CN105510642B - Nano magnetic heating in-situ detector and detection method based on scanning probe microscopy - Google Patents

Abstract

The present invention provides a kind of nano magnetic heating in-situ detectors based on scanning probe microscopy.The apparatus system is used with magnetic, conductive, thermal conductivity probe, it is capable of providing the surface topography detection, magnetic signal detection and thermal signal detection mode of sample, by controlling displacement or the oscillation trajectory of probe, can in situ, synchronous, detection sample in real time magnetic, hot property.Therefore, which overcomes the limitation that existing scanning probe microscopy only has the function of the single detective of magnetic or thermal signal；Simultaneously, can in situ, synchronous, detection material in real time temperature be distributed with thermal conductivity, domain structure and its Dynamic Evolution, so as to the Coupling Rule and mechanism between the intuitively magnetic heat of research material, help to reduce the power consumption of micro-/nano parts, improve its stability and integrated level, promote significantly it is micro-/receive the development of scale science of heat.

Description

Nano-magnetothermal in-situ detection device and detection method based on scanning probe microscope

technical field

The application belongs to the technical field of signal detection, and in particular relates to a nanometer magnetothermal in-situ detection device and detection method based on a scanning probe microscope.

Background technique

The heating and heat dissipation of micro/nano devices is an important bottleneck restricting the stability and integration of electronic devices. Researching the thermal properties of materials at the micro/nano scale and understanding the physical processes of heat generation and heat dissipation has attracted people's attention, and has gradually developed into a new discipline - micro/nano scale thermal science.

Under service conditions, the heating and cooling process of materials is usually closely related to the microstructure and domain structure (including magnetic domain structure, ferroelectric/piezoelectric domain structure, conductive domain structure, etc.) of the material. Taking magnetic materials as an example, magnetic domain flipping under the drive of an external field will generate micro-area heating. If physical parameters such as magnetism, temperature, and thermal conductance can be imaged synchronously, in-situ, and in real time in the micro-area, it will be possible to Real-time observation of the heating point and heat dissipation path of the material, and the correlation between them and the structure and magnetism of the material can be obtained. It is of great significance to reduce power consumption, improve stability and integration. In addition, for magnetic refrigeration materials and magnetic nanocomposite thermoelectric materials, magnetic domain flipping under the action of an external field produces a thermal effect. The study of this thermal effect is of great significance for the exploration of material mechanism and the development of new materials.

The existing micro/nano-scale thermal detection technology can realize the measurement of micro-area temperature and thermal conductivity distribution, but it cannot detect physical parameters such as magnetism, temperature/thermal conductivity in situ, synchronously and in real time in the micro-area, thus Research on the in-depth understanding of heat generation and heat dissipation processes and their physical mechanisms is limited.

Contents of the invention

The technical purpose of the present invention is to provide a signal detection device at the micro/nano scale, which can be used for synchronous, in situ and real-time detection of materials at the micro/nano scale. The physical parameters of magnetism, temperature/thermal conductivity are detected.

The technical scheme adopted by the present invention to achieve the above technical purpose is: a micro/nano magneto-thermal multi-parameter in-situ detection device based on a scanning probe microscope, which is used for synchronous, in-situ and real-time detection of micro Magnetic and temperature, thermal conductivity, Seebeck coefficient and other pyroelectric parameters, and synchronous imaging; the detection device includes the following:

(1) Scanning probe microscope platform, probe, probe control unit

Probe control unit: for driving or controlling the displacement and/or vibration of the probe;

Probe: magnetic, electrical and thermal conductivity;

The probe includes a probe arm and a needle tip;

(2) Morphology and magnetic signal detection platform

Including a displacement or vibration signal acquisition unit for receiving the displacement signal or vibration signal of the probe;

The probe scans the sample surface horizontally and directionally from the initial position. During the scanning process, the probe tip is controlled to be in point contact or vibration point contact with the sample surface. The displacement or vibration signal acquisition unit receives the longitudinal displacement signal or vibration signal of the probe tip. Analyze the shape signal of the sample;

After the probe returns to the initial position and is lifted up for a certain distance, the sample surface is scanned according to the lateral orientation. During the scanning process, the probe tip is controlled to perform longitudinal displacement or vibration along the profile curve, and the displacement or vibration signal is collected. The unit receives the longitudinal displacement signal or vibration signal of the probe tip, and obtains the magnetic signal of the sample through collection and analysis;

(3) Thermal signal detection platform

Including thermal circuit and thermal signal acquisition unit;

In the thermal circuit, the electrical signal is excited by the electrical signal applying unit, and the electrical signal flows into the probe and heats the probe. The probe and the sample perform heat exchange, so that the voltage signal in the thermal circuit changes. Change to obtain the thermal signal of the sample;

(4) Central control unit

It is used to initialize each unit of the system, control each unit of the system, receive the shape, magnetic, and thermal signals of the sample, and obtain the image of the shape, magnetic, and thermal signals of the sample after analysis.

Preferably, the scanning probe microscope platform is provided with a resistance heating stage for providing a variable temperature environment.

Preferably, the scanning probe microscope platform is provided with an energized coil for providing a magnetic field environment.

The present invention also provides a preferred probe structure. As shown in Figures 1 and 2, the probe includes a probe arm 1 and a needle point 2. The needle point 2 is composed of a needle point body 3 and a covering layer. Film one 4 on the surface, film two 5 on the surface of film one, and film three 6 on the surface of film two; film one 4 has conductivity, film two 5 has electrical insulation, film three 6 has magnetic properties, film one 4 and film three The materials of 6 are different; and, thin film one 4, thin film two 5 and thin film three 6 form a thermocouple structure, that is: at the tip of the needle point body, the surface of thin film one 4 is thin film three 6, and the remaining parts except the tip of the body, Film two 5 is located between film one 4 and film three 6 .

The material of the thin film-4 is not limited, including one material or a combination of two or more materials in metals and semiconductors with good electrical conductivity, such as bismuth (Bi), nickel (Ni), cobalt (Co), potassium ( K) and other metals and their alloys, at least one of semiconductors such as graphite and graphene.

The material of the thin film 25 is not limited, including semiconductors, inorganic materials or organic materials with certain insulating properties, such as zinc oxide (ZnO), bismuth ferrite (BiFeO ₃ ), lithium cobaltate (LiCoO ₂ ), nickel oxide ( NiO), cobalt oxide (Co ₂ O ₃ ), copper oxide (Cux _O ), silicon dioxide (SiO ₂ ), silicon nitride (SiN _x ), titanium dioxide (TiO ₂ ), tantalum pentoxide (Ta ₂ O ₅ ), niobium pentoxide (Nb ₂ O ₅ ), tungsten oxide (WO _x ), hafnium dioxide (HfO ₂ ), aluminum oxide (Al ₂ O ₃ ), carbon nanotubes, graphene, graphene oxide, non Crystalline carbon, copper sulfide ( _CuxS ), silver sulfide (Ag ₂ S), amorphous silicon, titanium nitride (TiN), polyimide (PI), polyamide (PAI), polyschiff base (PA ), polysulfone (PS) and the like.

The material of the thin film 36 is not limited, including ferromagnetic metals iron (Fe), cobalt (Co), nickel (Ni) and magnetic alloys.

The thermocouple structure composed of the first film, the second film and the third film can be obtained by the following preparation method:

Step 1. Prepare thin film-4 on the surface of the tip body by coating;

Step 2, using the coating method to prepare film two 5 on the surface of film one 4;

Step 3, using an etching method to remove the film 2 5 at the tip of the needle tip body, exposing the film 1 4;

Step 4. Prepare thin film 3 6 on the surface of thin film 1 exposed in step 3 by coating method, so that thin film 4 and thin film 3 6 are connected at the tip of the needle tip to form a thermocouple structure.

In the above-mentioned preparation method, the coating method in steps 1, 2, and 4 includes but is not limited to one of various solution spin coating methods, inkjet printing, solid sputtering, thermal evaporation, electron beam evaporation, etc. Or a combination of two or more; the method for removing the tip thin film 2 in step 3 includes but is not limited to dry etching, wet etching and other methods, such as ion etching, reactive ion etching, chemical etching and the like.

As shown in Figure 3, the thermocouple structure formed by the thin film one 4, the thin film two 5 and the thin film three 6 can also be obtained by another preparation method as follows:

Step 1. Using the coating method, film one 4, film two 5 and film three 6 are sequentially prepared on the surface of the needle tip body 3;

Step 2. Apply a voltage between the film 3 6 and the electrode layer 7, and use the tip discharge principle to adjust the distance between the film 3 6 and the electrode layer 7 to melt the film 3 6 at the tip of the needle point, exposing the film 2 5, and Other parts of the film 36 are not melted;

Step 3: remove the exposed film 2 5 described in step 2, and expose the film 1 4;

Step 4: Coating the exposed part with the same material as thin film three 6, so that thin film one 4 and thin film three 6 are connected at the tip of the needle tip to form a thermocouple structure.

In the above-mentioned preparation method, the coating method in steps 1 and 4 includes but is not limited to one or both of various solution spin coating methods, inkjet printing, solid sputtering, thermal evaporation or electron beam evaporation. more than one combination.

When the above-mentioned probe with a thermocouple structure is used, the working mode of the nano-magnetocaloric in-situ detection device based on the scanning probe microscope of the present invention includes the following two types, which are respectively used to detect the morphology, magnetic signal and thermal signal of the sample:

(1) Mode 1: used to detect the surface morphology and magnetic signal of the sample

The probe drive unit drives the probe to move to an initial position on the sample surface. From the initial position, the probe scans the sample surface in a transverse direction. During the scanning process, the probe tip is controlled to make point contact or vibration point contact, displacement or vibration with the sample surface. The signal acquisition unit receives the longitudinal displacement signal or vibration signal of the probe tip, and analyzes the shape signal of the sample through the central control unit;

The probe returns to the initial position and lifts up a certain distance, and then scans the surface of the sample according to the lateral orientation. During the scanning process, the probe tip is controlled to move longitudinally or vibrate along the topographical image. The displacement Or the vibration signal acquisition unit receives the longitudinal displacement signal or vibration signal of the probe tip, and obtains the magnetic signal image of the sample through analysis by the central control unit;

(2) Mode 2: used to detect the thermal signal of the sample

The electrical signal application unit, film 1, and film 3 form a closed thermoelectric circuit; the probe driving unit drives the probe to a certain position on the sample surface, so that the needle tip is in contact with the sample surface, and the electrical signal application unit applies an electrical signal to the needle tip, and the current flows into the The needle tip is heated, and the needle tip and the sample perform heat exchange, so that a voltage signal is generated in the thermal circuit, the thermal signal of the sample is obtained through the thermal signal acquisition unit, and the thermal signal image of the sample is obtained through the analysis of the central control unit;

When the probe with the above-mentioned thermocouple structure is used, the method for in-situ, synchronous and real-time detection of the magnetic and thermal properties of the sample using the nano-magnetothermal in-situ detection device based on the scanning probe microscope of the present invention is as follows:

Step 1: The sample is fixed on the scanning probe microscope platform, using the above-mentioned detection mode 1, the probe is displaced to the initial position, and the sample surface is scanned along the transverse direction to obtain the topography image and magnetic signal image of the sample;

Step 2: The probe is moved to the initial position in step 1, and the above-mentioned detection mode 2 is used to scan the surface of the sample in the transverse orientation described in step 1 to obtain the thermal signal image of the sample;

The present invention also proposes another preferred probe structure. In this structure, as shown in FIG. 1 , the probe includes a probe arm 1 and a needle tip 2 . The needle tip 2, as shown in Figure 4, includes a needle tip body 3, a thermal resistance material layer 8, a conductive layer 9 and a magnetic layer 10; the thermal resistance material layer 8 is located on the surface of the needle tip body 3, and the magnetic layer 10 is located on the surface of the thermal resistance material layer; the conductive layer 9 is connected with the thermal resistance material layer 8; the thermal resistance material layer 8 is composed of thermal resistance material, and is used to detect the temperature change and thermal conductivity of the sample; the conductive layer 9 is composed of conductive material, connected with the thermal resistance material, and is used to detect thermal resistance The change of material resistance; the magnetic layer 10 is made of magnetic material and is used to detect the magnetic signal of the sample.

The material of the thermal resistance material layer 8 is not limited, including silicon with low doping, semiconductor and metal resistance materials.

The material of the conductive layer 9 is not limited, including one material or a combination of two or more materials in metals and semiconductors with good electrical conductivity, such as bismuth (Bi), nickel (Ni), cobalt (Co), potassium ( K) and other metals and their alloys, at least one of semiconductors such as graphite and graphene.

The material of the magnetic layer 10 is not limited, including ferromagnetic metals iron (Fe), cobalt (Co), nickel (Ni) and magnetic alloys.

Preferably, an insulating layer is provided between the thermal resistance material layer and the magnetic layer.

The preparation method of above-mentioned probe is as follows:

Step 1. Prepare a thermal resistance material layer 8 on the surface of the tip body by coating;

Step 2, preparing a conductive layer 9 on the surface of the tip body by coating;

Step 3, preparing the magnetic layer 10 on the surface of the thermal resistance material layer 8 by coating.

In the above-mentioned preparation method, the coating methods in the steps 1, 2, and 3 include but are not limited to various solution spin coating methods, inkjet printing, etching, solid sputtering, thermal evaporation, electron beam evaporation, etc. one or a combination of two or more.

Preferably, the thickness of the thermal resistance material layer 8 is 0.1 μm˜10 μm.

Preferably, the thickness of the conductive layer 9 is 0.1 μm˜1 μm.

When the above-mentioned probe with a thermal resistance structure is used, the working mode of the nano-magnetothermal in-situ detection device based on the scanning probe microscope of the present invention includes the following two types, which are respectively used to detect the morphology, magnetic signal and thermal signal of the sample:

(1) Mode 1: used to detect the surface morphology and magnetic signal of the sample

The probe drive unit drives the probe to move to an initial position on the sample surface. From the initial position, the probe scans the sample surface in a transverse direction. During the scanning process, the probe tip is controlled to make point contact or vibration point contact, displacement or vibration with the sample surface. The signal acquisition unit receives the longitudinal displacement signal or vibration signal of the probe tip, and analyzes the shape signal of the sample through the central control unit;

The probe returns to the initial position and lifts up a certain distance, and then scans the surface of the sample according to the lateral orientation. During the scanning process, the probe tip is controlled to move longitudinally or vibrate along the topographical image. The displacement Or the vibration signal acquisition unit receives the longitudinal displacement signal or vibration signal of the probe tip, and obtains the magnetic signal image of the sample through analysis by the central control unit;

(2) Mode 2: used to detect the thermal signal of the sample

The electrical signal application unit, the conductive layer and the thermal resistance material layer form a closed loop; the electrical signal application unit heats the thermal resistance material layer, and then heats the probe tip, so that the temperature of the probe tip is different from the temperature of the sample (generally selected higher than the temperature of the sample); the probe driving unit drives the probe tip to contact the sample, and heat exchange occurs between the sample and the probe tip, which in turn affects the temperature of the thermal resistance material layer. Due to the thermal resistance effect, the thermal resistance material layer When the resistance value changes, it is collected by the thermal signal acquisition unit and then analyzed by the central control unit to obtain the thermal signal image of the sample.

In the above structure, the thermal resistance material layer 8 and the magnetic layer 10 are arranged in layers at the tip of the needle tip body. Considering that in the actual preparation process, because the tip of the needle tip body has a small cross-section, it is difficult to prepare the covering layer. It is especially difficult to prepare the multi-layer laminated structure; on the other hand, in this multi-layer laminated structure, the detection of magnetic signals and thermal signals is concentrated at the tip of the needle tip body, and the damage of one layer of film will cause the entire probe to Ineffective, the utilization rate is not high.

For this reason, the present invention improves the lamination structure, and the thermal resistance material layer and the conductive layer are arranged at the position of the probe wall, and only the magnetic layer is arranged at the tip of the probe, that is, the magnetic layer and the thermal resistance material layer, the conductive layer, and the conductive layer. This structure is specifically: the probe includes a probe arm and a needle tip; the needle tip includes a needle tip body and a magnetic layer on its surface, and a thermal resistance material layer is arranged on the probe arm at a certain distance from the needle tip, that is, The thermal resistance material layer is not electrically connected to the magnetic layer, while the conductive layer is electrically connected to the thermal resistance material layer 8 . Preferably, the conductive layer is arranged on the surface of the thermal resistance material layer.

When the above-mentioned probe with a thermal resistance structure is used, the working mode of the nano-magnetothermal in-situ detection device based on the scanning probe microscope of the present invention includes the following two types, which are respectively used to detect the morphology, magnetic signal and thermal signal of the sample:

(1) Mode 1: used to detect the surface morphology and magnetic signal of the sample

The probe drive unit drives the probe to move to an initial position on the sample surface. From the initial position, the probe scans the sample surface in a transverse direction. During the scanning process, the probe tip is controlled to make point contact or vibration point contact, displacement or vibration with the sample surface. The signal acquisition unit receives the longitudinal displacement signal or vibration signal of the probe tip, and analyzes the shape signal of the sample through the central control unit;

The probe returns to the initial position and lifts up a certain distance, and then scans the surface of the sample according to the lateral orientation. During the scanning process, the probe tip is controlled to move longitudinally or vibrate along the topographical image. The displacement Or the vibration signal acquisition unit receives the longitudinal displacement signal or vibration signal of the probe tip, and obtains the magnetic signal image of the sample through analysis by the central control unit;

(2) Mode 2: used to detect the thermal signal of the sample

The electrical signal application unit, the conductive layer and the thermal resistance material layer form a closed loop; the electrical signal application unit heats the thermal resistance material layer; the probe driving unit drives the probe tip to contact the sample, and the sample and the probe tip undergo heat exchange, The heat affects the temperature of the thermal resistance material layer through the air and the probe wall. Due to the thermal resistance effect, the resistance value of the thermal resistance material layer changes. After being collected by the thermal signal acquisition unit, it is analyzed by the central control unit to obtain the thermal resistance of the sample. signal image;

When the probe with the above-mentioned thermal resistance structure is used, the method for in-situ, synchronous and real-time detection of the magnetic and thermal properties of the sample using the nano-magnetothermal in-situ detection device based on the scanning probe microscope of the present invention is as follows:

Step 1: The sample is fixed on the scanning probe microscope platform, using the above-mentioned detection mode 1, the probe is displaced to the initial position, and the sample surface is scanned along the transverse direction to obtain the topography image and magnetic signal image of the sample;

Step 2: The probe is moved to the initial position in step 1, and the above-mentioned detection mode 2 is used to scan the surface of the sample horizontally and directionally as described in step 1 to obtain the thermal signal image of the sample.

The present invention also provides a preferred probe control unit structure, as shown in FIG. 5 , the probe control unit is a piezoelectric driver connected with the probe. At this time, the displacement signal acquisition unit includes a light source, a photoelectric four-quadrant detector and a signal processor; in the working state, the sample is placed on the platform of the scanning probe microscope, the probe vibrates under the action of the piezoelectric driver, and the light source illuminates the probe. The needle arm, the reflected signal is collected by the photoelectric four-quadrant detector, and then connected with the central control unit after being processed by the signal processor.

As an implementation manner, as shown in FIG. 5 , the signal processor includes a front-end amplifier, an integrator, a high-voltage amplifier, a delayer, a lock-in amplifier, and a back-end amplifier. The photoelectric four-quadrant detector is connected to the integrator through the front-end amplifier, and the integrator is connected to the high-voltage amplifier. One signal of the high-voltage amplifier is fed back to the piezoelectric driver to form a closed-loop control. The other signal is connected to the delayer, and the delayer It is connected with the 1ω (one times frequency channel) and 3ω (three times frequency channel) channels of the lock-in amplifier, the lock-in amplifier is connected with the back-end amplifier, and the back-end amplifier is connected with the control center.

As an implementation manner, as shown in FIG. 5 , the thermal signal acquisition unit includes a delayer, a lock-in amplifier and a back-end amplifier.

To sum up, the nano-magnetothermal in-situ detection device based on the scanning probe microscope provided by the present invention has the following advantages:

(1) Existing detection devices based on scanning probe microscopes only have the detection function of magnetic or thermal signals. The present invention breaks through the limitation of the detection function and provides the detection function of magnetic and thermal signals;

(2) By applying magnetic field, electric field and temperature field in situ, it can simulate the actual service environment, realize in situ excitation of magnetic/electric domain flipping and introduction of leakage current under the excitation or action of multiple physical fields, and realize in situ and synchronous , Real-time detection of material temperature and thermal conductance distribution, magnetic domain structure and its dynamic evolution process, so it is possible to study the magnetic-thermal coupling law and mechanism of materials in situ and intuitively.

Therefore, the present invention expands the function of the scanning probe microscope, and not only provides an advanced detection platform for the research of magnetoelectric functional materials and devices, but also provides a platform for reducing the power consumption of micro/nano devices and improving their stability and integration. At the same time, it will greatly promote the development of micro/nanoscale thermal science.

Description of drawings

Fig. 1 is the top view structure schematic diagram of the probe with thermocouple structure in the nano-magnetocaloric in-situ detection device based on the scanning probe microscope of the present invention;

Figure 2 is an enlarged view of the probe tip with a thermocouple structure in Figure 1;

Fig. 3 is a schematic diagram of the probe tip with thermocouple structure prepared in Fig. 1 by tip discharge melting method;

Fig. 4 is a schematic diagram of the probe tip structure with a thermal resistance structure in the nano-magnetothermal in-situ detection device based on the scanning probe microscope of the present invention;

Fig. 5 is a schematic diagram of a preferred functional structure of the nano-magnetothermal in-situ detection device based on the scanning probe microscope of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments. It should be noted that the following embodiments are intended to facilitate the understanding of the present invention, but do not limit it in any way.

Among them: 1-probe arm, 2-needle tip, 3-needle tip body, 4-film one, 5-film two, 6-film three, 7-electrode layer, 8-thermal resistance material layer, 9-conductive layer, 10 - Magnetic layer.

In this embodiment, the nano-magnetothermal in-situ detection device based on a scanning probe microscope includes a scanning probe microscope platform, a probe, a probe control unit, a morphology and magnetic signal detection platform, a thermal signal detection platform, and a central control unit .

The probe control unit is used to drive or control the probe to perform displacement and/or vibration;

The morphology and magnetic signal detection platform includes a displacement or vibration signal acquisition unit, which is used to receive the displacement signal or vibration signal of the probe;

The thermal signal detection platform includes a thermal circuit and a thermal signal acquisition unit; the thermal circuit excites the electrical signal by the electrical signal application unit, and the electrical signal flows into the probe and heats the probe, and the probe and the sample perform heat exchange, so that the thermal circuit The voltage signal changes, and the thermal signal of the sample is obtained through collection;

The central control unit is used to initialize each unit of the system, control each unit of the system, receive the shape, magnetic, and thermal signals of the sample, and obtain the image of the shape, magnetic, and thermal signals of the sample after analysis.

As shown in FIG. 1 , the probe includes a probe arm 1 and a needle tip 2 .

The structure of the needle tip 2 is shown in FIG. 2 . It is composed of the needle tip body 3 and the surface covering layer. The surface covering layer consists of film one 4 , film one 4 , film two 5 , film two 5 and film three 6 . Thin film one 4 has electrical conductivity, thin film two 5 has electrical insulation, thin film three 6 has magnetic properties, and thin film one 4 is different from the material of thin film three 6; and, thin film one 4, thin film two 5 and thin film three 6 form a thermocouple structure, That is: at the tip of the needle point body 3, the surface of the film one 4 is covered with the film three 6, and for the other parts of the needle point body 3 except the tip, the film two 5 is located between the film one 4 and the film three 6.

The probe tip with a thermocouple structure can be prepared by the following method, which includes the following steps:

Step 1. Prepare a thin film-4 on the surface of the needle tip body 3 by a coating method, such as solution spin coating, inkjet printing, solid sputtering, thermal evaporation, or electron beam evaporation;

Step 2, using methods such as solution spin coating, inkjet printing, solid sputtering, thermal evaporation, or electron beam evaporation to prepare a thin film 25 on the surface of the tip body 3 by using a coating method;

Step 3, using methods such as dry etching and wet etching, such as ion etching, reactive ion etching, chemical etching, etc., to remove the film 2 5 at the tip of the needle tip body 3, exposing the film 1 4;

Step 4. Prepare a thin film 36 on the surface of the tip body 3 by using methods such as solution spin coating, inkjet printing, solid sputtering, thermal evaporation, or electron beam evaporation to make the thin film at the tip of the tip body 3 The surface of 4 is covered with film three 6, except for the tip, film two 5 is located between film one 4 and film three 6.

The material of film one 4 is conductive metal Pt with a thickness of 100nm, the material of film two 5 is insulating layer Al ₂ O ₃ with a thickness of 200nm, and the material of film three 6 is magnetic Ni with a thickness of 100nm.

The probe control unit uses a piezoelectric driver connected to the probe. The piezoelectric driver is an MFP-3D-SA-SCANNER scanner produced by Asylum Research Company of the United States, and the scanning range is X×Y=90×90 μm ² .

As shown in Figure 5, the displacement or vibration signal acquisition unit includes a light source, a photoelectric four-quadrant detector and a signal processor. The signal processor consists of a front-end amplifier, an integrator, a high-voltage amplifier, a delayer, a lock-in amplifier and a back-end amplifier. In the working state, the sample is placed on the scanning probe microscope platform, the probe vibrates under the action of the piezoelectric driver, the light source illuminates the probe arm, the reflected signal is collected by the photoelectric four-quadrant detector, and then connected to the integrator through the front-end amplifier. The integrator is connected to the high-voltage amplifier, and one signal of the high-voltage amplifier is fed back to the piezoelectric driver to form a closed-loop control, and the other signal is connected to the delayer, and the delayer is connected to the lock-in amplifier's 1ω (one frequency channel) and 3ω (triple frequency channel) channels are connected, the lock-in amplifier is connected with the back-end amplifier, and the back-end amplifier is connected with the control center.

The control center is composed of a computer, an initialization module and a control module.

The thermal signal acquisition unit is composed of a delayer, a lock-in amplifier and a back-end amplifier. The electrical signal acquisition unit is composed of a delayer, a lock-in amplifier and a back-end amplifier. In this embodiment, the thermal signal acquisition unit, the electrical signal acquisition unit and the signal processor are integrated.

The electrical signal applying unit in the thermal circuit is a current source.

The electrical circuit consists of an electrical signal applying unit as a voltage source.

In this embodiment, the Fe film grown on the ferroelectric substrate PMN-PT is selected as the research sample, and the thickness of the sample is 90 nm.

Using the above-mentioned nano-magnetothermal in-situ detection device based on scanning probe microscope, the method of in-situ, synchronous and real-time detection of the magnetic and thermal properties of the sample at room temperature is as follows:

(1) The sample is fixed on the scanning probe microscope platform, and the initial parameters of each unit of the system are set through the initialization module;

(2) Under the action of the control module, the piezoelectric driver drives the probe to move to an initial position on the sample surface, the light source irradiates the probe arm, and the reflected signal is collected by a photoelectric four-quadrant detector; Carry out directional scanning. During the scanning process, the film 36 on the surface of the control probe tip 2 is in point contact or vibration point contact with the sample surface. The reflected signal is collected by a photoelectric four-quadrant detector, and then connected to the integrator through the front-end amplifier. The integrator is connected to the The high-voltage amplifier is connected, and one signal of the high-voltage amplifier is fed back to the piezoelectric driver to form a closed-loop control. The other signal is connected to the delayer, and the delayer is connected to the 1ω (one-fold frequency channel) and 3ω (three-fold frequency channel) of the lock-in amplifier. frequency channel) channel is connected, the lock-in amplifier is connected with the back-end amplifier, and the back-end amplifier is connected with the computer, and the topography signal image of the sample is obtained after analysis and processing;

(3) The piezoelectric driver drives the probe back to the initial position described in step (2) and lifts up a certain distance, and scans the sample surface again according to the lateral orientation described in step (2). During the scanning process, the probe is controlled. The thin film 36 on the surface of the needle tip 2 performs longitudinal displacement or vibration along the topography image obtained in step (2), the displacement or vibration signal acquisition unit receives the longitudinal displacement signal or vibration signal of the probe tip, and the reflected signal passes through the photoelectric four-quadrant detector Collect, then as described in step (1), through the front-end amplifier, integrator, high-voltage amplifier, time delay device, lock-in amplifier, back-end amplifier, be connected with computer, obtain the magnetic signal image of sample after analyzing and processing;

(4) The piezoelectric driver drives the probe back to the initial position described in step (2);

(5) Make the film 3 6 on the surface of the needle tip 2 contact the sample surface; the current source, the film 1 4 and the film 3 6 form a closed thermoelectric circuit; the current source applies an electrical signal to the probe, and the current flows into the needle tip 2 and performs Heating, heat exchange between the needle tip 2 and the sample, so that the voltage signal in the thermal circuit changes, the signal is collected, and connected to the computer through the delayer, lock-in amplifier and back-end amplifier, and the sample at the position is obtained after analysis and processing thermal signature image;

(6) According to the lateral direction described in step (2), the piezoelectric driver drives the probe to the next position;

(7) Steps (5) and (6) are repeated for each point until the sample surface is scanned point by point according to the transverse direction described in step (2).

Example 2:

In this embodiment, the nano-magnetothermal in-situ detection device based on the scanning probe microscope is exactly the same as that in Embodiment 1.

The difference is that the probe tip with a thermocouple structure is prepared by another method, which includes the following steps:

Step 1. Using the coating method, film one 4, film two 5 and film three 6 are sequentially prepared on the surface of the needle tip body 3;

Step 2. Apply a voltage between the film 3 6 and the electrode layer 7, and use the tip discharge principle to adjust the distance between the film 3 6 and the electrode layer 7 to melt the film 3 6 at the tip of the needle point, exposing the film 2 5, and Other parts of the film 36 are not melted;

Step 3: remove the exposed film 2 5 described in step 2, and expose the film 1 4;

Step 4: Coating the exposed part with the same material as thin film three 6, so that thin film one 4 and thin film three 6 are connected at the tip of the needle tip to form a thermocouple structure.

The method for in-situ, synchronous and real-time detection of the magnetic and thermal properties of the sample at room temperature using the nano-magnetocaloric in-situ detection device based on the scanning probe microscope is exactly the same as that in Example 1.

Example 3:

In this embodiment, the structure of the nano-magnetocaloric in-situ detection device based on the scanning probe microscope is basically the same as that in Embodiment 1, except that a probe with a thermal resistance structure is used.

As shown in FIG. 1 , the probe includes a probe arm 1 and a needle tip 2 . The needle tip 2, as shown in Figure 4, includes a needle tip body 3, a thermal resistance material layer 8, a conductive layer 9 and a magnetic layer 10; the thermal resistance material layer 8 is located on the surface of the needle tip body 3, and the magnetic layer 10 is located on the surface of the thermal resistance material layer; the conductive layer 9 is in electrical communication with the thermal resistance material layer 8 .

The thermal resistance material layer 8 is made of low-doped silicon with a thickness of 2m, and the conductive layer 9 is made of bismuth (Bi), nickel (Ni), cobalt (Co), potassium (K), graphite, and graphene. , the thickness is 1 μm, the material of the magnetic layer 10 is iron (Fe), cobalt (Co) or nickel (Ni), and the thickness is 0.1 μm.

The preparation method of above-mentioned probe is as follows:

Step 1. Prepare a thermal resistance material layer 8 on the surface of the needle tip body by coating methods such as solution spin coating, inkjet printing, etching, solid sputtering, thermal evaporation, and electron beam evaporation;

Step 2. Prepare a conductive layer 9 on the surface of the needle tip body by coating methods such as solution spin coating, inkjet printing, etching, solid sputtering, thermal evaporation, and electron beam evaporation, and the conductive layer is connected to the thermal resistance material layer 8 ;

Step 3. Prepare the magnetic layer 10 on the surface of the thermal resistance material layer 8 by using coating methods such as solution spin coating, inkjet printing, etching, solid sputtering, thermal evaporation, and electron beam evaporation.

Using the above-mentioned nano-magnetothermal in-situ detection device based on scanning probe microscope, the method of in-situ, synchronous and real-time detection of the magnetic and thermal properties of the sample at room temperature is as follows:

(1) The sample is fixed on the scanning probe microscope platform, and the initial parameters of each unit of the system are set through the initialization module;

(2) Under the action of the control module, the piezoelectric driver drives the probe to move to an initial position on the sample surface, the light source illuminates the probe arm, and the reflected signal is collected by a photoelectric four-quadrant detector; Carry out directional scanning. During the scanning process, the magnetic layer 10 on the surface of the control probe tip 2 is in point contact or vibration point contact with the sample surface. The reflected signal is collected by a photoelectric four-quadrant detector, and then connected to the integrator through the front-end amplifier. The integrator and The high-voltage amplifier is connected, and one signal of the high-voltage amplifier is fed back to the piezoelectric driver to form a closed-loop control. The other signal is connected to the delayer. frequency channel) channel is connected, the lock-in amplifier is connected with the back-end amplifier, and the back-end amplifier is connected with the computer, and the topography signal image of the sample is obtained after analysis and processing;

(3) The piezoelectric driver drives the probe back to the initial position described in step (2) and lifts up a certain distance, and scans the sample surface again according to the lateral orientation described in step (2). During the scanning process, the probe is controlled. The magnetic layer 10 on the surface of the needle tip 2 performs longitudinal displacement or vibration along the topography image obtained in step (2), the displacement or vibration signal acquisition unit receives the longitudinal displacement signal or vibration signal of the probe tip, and the reflected signal passes through the photoelectric four-quadrant detector Collect, then as described in step (1), through the front-end amplifier, integrator, high-voltage amplifier, time delay device, lock-in amplifier, back-end amplifier, be connected with computer, obtain the magnetic signal image of sample after analyzing and processing;

(4) The piezoelectric driver drives the probe back to the initial position described in step (2);

(5) Make the magnetic layer 10 on the surface of the needle point 2 contact the sample surface; the current source, the conductive layer 9, and the thermal resistance material layer 8 form a closed thermoelectric circuit; the electric signal application unit heats the thermal resistance material layer 8, and then The probe tip is heated so that the temperature of the probe tip is higher than the temperature of the sample; the probe driving unit drives the probe tip to contact the sample, and heat exchange occurs between the sample and the probe tip, thereby affecting the temperature of the thermal resistance material layer 8 , due to the thermal resistance effect, the resistance value of the thermal resistance material layer 8 changes, the signal is collected, and connected to the computer through the delayer, lock-in amplifier and back-end amplifier, and the thermal signal of the sample at the position is obtained after analysis and processing image;

(6) According to the lateral direction described in step (2), the piezoelectric driver drives the probe to the next position;

(7) Steps (5) and (6) are repeated for each point until the sample surface is scanned point by point according to the transverse direction described in step (2).

Example 4:

In this embodiment, the nano-magnetothermal in-situ detection device based on the scanning probe microscope is basically the same as that in Embodiment 1, except that a probe with a thermal resistance structure is used.

In this structure, the probe includes a probe arm and a needle tip. The needle tip includes a needle tip body and a magnetic layer on its surface. A thermal resistance material layer is arranged at a certain distance from the needle tip on the probe arm, that is, there is no electrical connection between the thermal resistance material layer and the magnetic layer, and the conductive layer is arranged on the thermal resistance material layer. surface.

The material of the thermal resistance material layer 8 is low-doped silicon with a thickness of 5 μm, and the material of the conductive layer 9 is one of bismuth (Bi), nickel (Ni), cobalt (Co), potassium (K), graphite, and graphene , the thickness is 1 μm, the material of the magnetic layer 10 is iron (Fe), cobalt (Co) or nickel (Ni), and the thickness is 0.1 μm.

Using the above-mentioned nano-magnetothermal in-situ detection device based on scanning probe microscope, the method of in-situ, synchronous and real-time detection of the magnetic and thermal properties of the sample at room temperature is as follows:

(1) The sample is fixed on the scanning probe microscope platform, and the initial parameters of each unit of the system are set through the initialization module;

(2) Under the action of the control module, the piezoelectric driver drives the probe to move to an initial position on the sample surface, the light source illuminates the probe arm, and the reflected signal is collected by a photoelectric four-quadrant detector; Carry out directional scanning. During the scanning process, the magnetic layer on the surface of the control probe tip is in point contact or vibration point contact with the sample surface. The reflected signal is collected by a photoelectric four-quadrant detector, and then connected to the integrator through the front-end amplifier, and the integrator is connected to the high-voltage amplifier. One signal of the high-voltage amplifier is fed back to the piezoelectric driver to form a closed-loop control. The other signal is connected to the delayer. ) channels are connected, the lock-in amplifier is connected with the back-end amplifier, and the back-end amplifier is connected with the computer, and the topography signal image of the sample is obtained after analysis and processing;

(3) The piezoelectric driver drives the probe back to the initial position described in step (2) and lifts up a certain distance, and scans the sample surface again according to the lateral orientation described in step (2). During the scanning process, the probe is controlled. The magnetic layer on the surface of the needle tip is longitudinally displaced or vibrated along the topography image obtained in step (2), and the displacement or vibration signal acquisition unit receives the longitudinal displacement signal or vibration signal of the probe tip, and the reflected signal is collected by a photoelectric four-quadrant detector. Then as described in step (1), through front-end amplifier, integrator, high-voltage amplifier, time delay device, lock-in amplifier, back-end amplifier, be connected with computer, obtain the magnetic signal image of sample after analyzing and processing;

(4) The piezoelectric driver drives the probe back to the initial position described in step (2);

(5) Make the magnetic layer on the surface of the needle point contact with the sample surface; the current source, the conductive layer, and the thermal resistance material layer form a closed thermoelectric circuit; the electric signal applying unit heats the thermal resistance material layer; the probe driving unit drives the probe Displace to a certain position on the surface of the sample, so that the magnetic layer on the surface of the needle tip is in contact with the surface of the sample, heat exchange occurs between the sample and the needle tip, and the heat affects the temperature of the thermal resistance material layer through the air and the magnetic layer. Due to the thermal resistance effect, the thermal resistance The resistance value of the material layer changes, the signal is collected, and connected to the computer through the delayer, lock-in amplifier and back-end amplifier, and the thermal signal image of the sample at the position is obtained after analysis and processing;

(6) According to the lateral direction described in step (2), the piezoelectric driver drives the probe to the next position;

(7) Steps (5) and (6) are repeated for each point until the sample surface is scanned point by point according to the transverse direction described in step (2).

The embodiments described above have described the technical solutions of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention, and are not intended to limit the present invention. All done within the principle scope of the present invention Any modification, supplement or substitution in a similar manner shall be included within the protection scope of the present invention.

Claims (13)

1. a kind of nano magnetic heating in-situ detector based on scanning probe microscopy, it is characterized in that：Including as follows：

(1) scanning probe microscopy platform, probe, probe control unit

Probe control unit：For driving or controlling probe to carry out displacement and/or vibration；

Probe：With magnetic, electric conductivity and thermal conductivity；

The probe includes feeler arm and needle point；

(2) pattern and magnetic signal detection platform

Including displacement or vibration signals collecting unit, for receiving the displacement signal of probe or vibration signal；

Probe carries out sample surfaces transversal orientation scanning from initial position, and probe tip and sample surfaces are controlled in scanning process Point contact, displacement or vibration signals collecting unit receive the length travel signal or vibration signal of probe tip, acquired to obtain The topography signal of sample；

Then, probe is back to initial position and raises upwards after certain distance according to the transversal orientation to sample surfaces It is scanned, probe tip is controlled to carry out length travel or vibration, displacement or vibration signal along topography profile in scanning process Collecting unit receives the length travel signal or vibration signal of probe tip, and acquired analysis obtains the magnetic signal of sample；

(3) thermal signal detection platform

Including calorifics circuit and thermal signal collecting unit；

Electric signal is encouraged in the calorifics circuit by electric signal applying unit, which flows into probe and probe is added Heat, probe carry out heat exchange with sample, the voltage signal in calorifics circuit are made to change, acquired analysis obtains the heat of sample Signal；

(4) centralized control unit

For initializing system each unit, control system each unit receives the pattern, magnetic, thermal signal of sample, sample is obtained after analysis Pattern, magnetic, the thermal signal image of product.

2. the nano magnetic heating in-situ detector based on scanning probe microscopy as described in claim 1, it is characterized in that：It is described Probe control unit be the piezoelectric actuator being connected with feeler arm；

The displacement or vibration signals collecting unit include light source, photoelectricity four-quadrant detector and signal processor；

During working condition, sample is placed in scanning probe microscopy platform, and probe carries out displacement or shaken under piezoelectric actuator effect Dynamic, light source irradiation feeler arm, reflection signal is collected by photoelectricity four-quadrant detector, then after signal processor processes with Centralized control unit is connected.

3. the nano magnetic heating in-situ detector based on scanning probe microscopy as claimed in claim 2, it is characterized in that：It is described Signal processor include front-end amplifier, integrator, high-voltage amplifier, delayer, lock-in amplifier and backend amplifier；Light Electric four-quadrant detector is connected by front-end amplifier with integrator, and integrator is connected with high-voltage amplifier, high voltage amplifier The signal all the way of device feeds back to piezoelectric actuator, forms closed-loop control, and another way signal is connected with delayer, delayer and lock One frequency multiplication chain of phase amplifier is connected with frequency tripling channel channel, and lock-in amplifier is connected with backend amplifier, rear end Amplifier is connected with control centre.

4. the nano magnetic heating in-situ detector based on scanning probe microscopy as described in claim 1, it is characterized in that：It is described Thermal signal collecting unit include delayer, lock-in amplifier and backend amplifier.

5. the nano magnetic heating in-situ investigation based on scanning probe microscopy as described in any claim in Claims 1-4 Device, it is characterized in that：The needle point is made of needle point ontology with coating, and coating is by being covered in the thin of needle point body surface The film three that film one, the film two of one surface of film covering, two surface of film cover forms；Film one is conductive, film Two with electrical insulating property, film three with magnetism, film one is different from the material of film three；Also, film one, film two and thin Film three forms thermocouple structure.

6. the nano magnetic heating in-situ detector based on scanning probe microscopy as claimed in claim 5, it is characterized in that：It is described Film one, the thermocouple structure that forms of film two and film three obtained using following preparation method：

Step 1 prepares film one using the method for plated film in needle point body surface；

Step 2 prepares film two using the method for plated film on one surface of film；

Step 3 removes the film two at needle point body tip using the method for etching, exposes film one；

Step 4 prepares film three using the method for plated film in one surface of film that step 3 is exposed, and film one is made to exist with film three Needle point tip position connects, and forms thermocouple structure；

Alternatively, the thermocouple structure that the film one, film two and film three are formed is obtained using following preparation method：

Step 1, the method using plated film prepare film one, film two and film three in needle point body surface successively；

Step 2 applies voltage between film three and electrode layer, using point discharge principle, by adjusting film three and electrode Distance between layer, melts the film three of needle point point, exposes film two, and other position films three do not melt；

Step 3：The film two that removal step 2 is exposed exposes film one；

Step 4：Using the method for plated film, the material identical with film three is plated in step 2 extending part, makes film one and film three It is connected at needle point tip position, forms thermocouple structure.

7. the nano magnetic heating in-situ detector based on scanning probe microscopy as claimed in claim 6, it is characterized in that：Including The following two kinds detection mode：

(1) detection mode one：For detecting the surface topography of sample and magnetic signal

Probe actuation unit driving probe is moved to sample surfaces initial position, and probe is from the initial position transversely to sample Surface is oriented scanning, and probe tip and sample surfaces point contact, displacement or vibration signals collecting list are controlled in scanning process Member receives the length travel signal or vibration signal of probe tip, analyzes to obtain the topography signal of sample through centralized control unit；

Then, probe is back to the initial position and raises certain distance upwards, according to the transversal orientation to sample Product surface is scanned, and probe tip is controlled to carry out length travel or vibration along feature image in scanning process, displacement or is shaken Dynamic signal gathering unit receives the length travel signal or vibration signal of probe tip, analyzes to obtain sample through centralized control unit Magnetic signal image；

(2) detection mode two：For detecting the thermal signal of sample

Electric signal applying unit, film one, film three form the calorifics circuit being closed；Probe actuation unit driving probe is moved to Sample surfaces position, makes probe tip be in contact with sample surfaces, and electric signal applying unit applies electric signal, electric current to probe It flows into probe tip and it is heated, probe tip carries out heat exchange with sample, sends out the voltage signal in calorifics circuit Changing obtains the thermal signal of sample through thermal signal collecting unit, analyzes to obtain the thermal signal figure of sample through centralized control unit Picture.

8. the nano magnetic heating in-situ investigation based on scanning probe microscopy as described in any claim in Claims 1-4 Device, it is characterized in that：The needle point includes needle point ontology, thermal resistance material layer, conductive layer and magnetosphere；Thermal resistance material Layer is located at needle point body surface, and magnetosphere is located at thermal resistance material surface；Conductive layer is mutually electrically connected with thermal resistance material layer.

9. the nano magnetic heating in-situ detector based on scanning probe microscopy as claimed in claim 8, it is characterized in that：Including The following two kinds detection mode：

(1) pattern one：For detecting the surface topography of sample and magnetic signal

Probe actuation unit driving probe is moved to sample surfaces initial position, and probe is from the initial position transversely to sample Surface is oriented scanning, and probe tip and sample surfaces point contact, displacement or vibration signals collecting list are controlled in scanning process Member receives the length travel signal or vibration signal of probe tip, analyzes to obtain the topography signal of sample through centralized control unit；

Probe is back to the initial position and raises certain distance upwards, then according to the transversal orientation to sample Surface is scanned, and probe tip is controlled to carry out length travel or vibration, displacement or vibration along feature image in scanning process Signal gathering unit receives the length travel signal or vibration signal of probe tip, analyzes to obtain sample through centralized control unit Magnetic signal image；

(2) pattern two：For detecting the thermal signal of sample

Electric signal applying unit, conductive layer and thermal resistance material layer form closed circuit；Electric signal applying unit is to thermal resistance material The bed of material is heated, and then probe tip is heated so that the temperature of probe tip is different from the temperature of sample；Probe drives Moving cell driving probe tip is in contact with sample, and with probe tip heat exchange occurs for sample, and then influences thermal resistance material The temperature of layer, due to thermal resistance effect so that the resistance value of thermal resistance material layer changes, after the acquisition of thermal signal collecting unit It is analyzed through centralized control unit, obtains the thermal signal image of sample.

10. the nano magnetic heating in-situ investigation based on scanning probe microscopy as described in any claim in Claims 1-4 Device, it is characterized in that：The needle point includes needle point ontology and the magnetosphere positioned at its surface, apart from needle point one on feeler arm Surely thermal resistance material layer is arranged at intervals, conductive layer is mutually electrically connected with thermal resistance material layer.

11. the nano magnetic heating in-situ detector based on scanning probe microscopy as claimed in claim 10, it is characterized in that：Institute 5 μm~50 μm are divided between stating.

12. the nano magnetic heating in-situ detector based on scanning probe microscopy as claimed in claim 10, it is characterized in that：Packet Include the following two kinds detection mode：

(1) pattern one：For detecting the surface topography of sample and magnetic signal

Probe actuation unit driving probe is moved to sample surfaces initial position, and probe is from the initial position transversely to sample Surface is oriented scanning, and probe tip and sample surfaces point contact, displacement or vibration signals collecting list are controlled in scanning process Member receives the length travel signal or vibration signal of probe tip, analyzes to obtain the topography signal of sample through centralized control unit；

Probe is back to the initial position and raises certain distance upwards, then according to the transversal orientation to sample Surface is scanned, and probe tip is controlled to carry out length travel or vibration, displacement or vibration along feature image in scanning process Signal gathering unit receives the length travel signal or vibration signal of probe tip, analyzes to obtain sample through centralized control unit Magnetic signal image；

(2) pattern two：For detecting the thermal signal of sample

Electric signal applying unit, conductive layer and thermal resistance material layer form closed circuit；Electric signal applying unit is to thermal resistance material The bed of material is heated；Probe actuation unit driving probe tip is in contact with sample, and with probe tip heat exchange occurs for sample, Heat influences the temperature of thermal resistance material layer through air or through probe wall, due to thermal resistance effect so that thermal resistance material layer Resistance value change, analyzed after the acquisition of thermal signal collecting unit through centralized control unit, obtain the thermal signal figure of sample Picture.

13. utilize the detection mode of the nano magnetic heating in-situ detector based on scanning probe microscopy described in claim 7 Original position, synchronization, the magnetic of real-time detection sample, hot property method, it is characterized in that：Include the following steps：

Step 1：Sample is fixed on scanning probe microscopy platform, and using above-mentioned detection mode one, probe is moved to initial bit It puts, transversely sample surfaces is oriented with scanning, obtain the feature image of sample and magnetic signal image；

Step 2：Probe is moved to the initial position in step 1, and using above-mentioned detection mode two, step 1 is carried out to sample surfaces Described in transversal orientation scanning, obtain the thermal signal image of sample.