CN114804115B - Block-shaped room-temperature ferromagnetism Si 1-x Ge x M y Semiconductor, preparation method and application thereof - Google Patents

Abstract

The invention provides a block-shaped room-temperature ferromagnetism Si _{1‑ x} Ge _x M _y A semiconductor, a method of manufacture, and uses thereof, the method comprising: s1: adding agate balls, silicon powder, germanium powder and manganese powder or iron powder into an agate ball milling tank containing absolute ethyl alcohol, wherein the mass ratio of the balls to the materials is 8:1, a step of; s2: placing the agate ball milling tank into a planetary ball mill to perform ball milling at a rotating speed of 200 r/min; s3: placing the ball-milled mixed powder containing absolute ethyl alcohol into a vacuum drying oven for drying to obtain dried mixed powder; s4: placing the dry mixed powder into a graphite die, and sintering by using discharge plasma, wherein the discharge plasma sintering conditions are as follows: heating to 800 ℃ at a heating rate of 100 ℃/min under a load pressure of 50MPa, then vacuum sintering at 800 ℃ for 0.5h, and naturally cooling to room temperature under a load pressure of 0MPa after sintering to obtain Si _1‑x Ge _x M _y The block, M is Mn or Fe. Si prepared by the invention _1‑x Ge _x M _y The semiconductor has uniform manganese or iron doping distribution, good crystallinity and high-temperature ferromagnetism.

Description

A bulk room temperature ferromagnetic Si1-xGexMy semiconductor, preparation method and application thereof

technical field

The invention relates to the technical field of magnetic semiconductor materials, in particular to a bulk room temperature ferromagnetic Si _{1-x Gex My} semiconductor, a preparation method and an application thereof.

Background technique

A magnetic semiconductor is a substance that has both semiconducting properties and ferromagnetism. Most ferromagnets such as iron are highly conductive, however, magnetic semiconductors are neither perfectly conductive nor purely resistive, and this unique combination of conductive and magnetic properties makes the material useful in new types of computers. Computers typically use semiconductors and electromagnets to perform different functions. Semiconductor silicon chips and other materials are used for processing and computing. Electromagnetic materials are often used for data storage, such as on the magnetic disks of hard drives. Magnetic semiconductor materials combine the functions of magnetic storage and semiconductor processing so that information can be manipulated and stored on the same chip and magnetic semiconductor computers can be started instantly.

At present, group IV dilute magnetic semiconductors have attracted great attention because they can provide both charge and spin for information processing and storage, and are compatible with current silicon integration technologies. However, for practical spintronics applications, an ideal dilute magnetic semiconductor should at least simultaneously possess room temperature ferromagnetism and high carrier mobility. At present, methods such as magnetron sputtering and thermal evaporation have been used to dope transition metal elements (such as Mn or Fe) into group IV materials (such as Si, Ge or SiGe) to prepare dilute magnetic semiconductors. However, these group IV dilute magnetic semiconductors usually exhibit an intrinsic Curie temperature lower than room temperature, and there are usually second phase precipitates (such as Mn-related clusters) formed, which is partly due to the transition metal elements in The equilibrium solubility in group IV materials is low (such as Mn, <10 ^-16 cm ^-3 ), therefore, exploring an alternative route to synthesize ideal group IV dilute magnetic semiconductors is a necessary research direction at present.

Contents of the invention

The object of the present invention is to provide a bulk room temperature ferromagnetic Si _{1-x Gex My} semiconductor, a preparation method and an application thereof. The bulk ferromagnetic Si _{1-x Gex My} semiconductor prepared by the preparation method of the present invention has uniform silicon, germanium and manganese or iron element distribution, and its Curie temperature increases with the increase of manganese or iron element content , up to 300K. The many technical effects that can be produced by the preferred technical solutions among the many technical solutions provided by the present invention are described in detail below.

To achieve the above object, the present invention provides the following technical solutions:

A method for preparing bulk room temperature ferromagnetic Si _{1-x Gex My} semiconductor provided by the present invention comprises the following steps:

S1: Add agate balls, silicon powder, germanium powder and manganese powder or iron powder into the agate ball mill tank containing absolute ethanol, and make the mass ratio of balls to materials 8:1;

S2: Put the above-mentioned agate ball mill jar into a planetary ball mill for ball milling at a speed of 200r/min;

S3: putting the ball-milled mixed powder containing absolute ethanol into a vacuum drying oven for drying to obtain a dried mixed powder;

S4: Put the dry mixed powder in step S3 into a graphite mold and use spark plasma sintering, wherein the spark plasma sintering conditions are: under a load pressure of 50MPa, heating to 800°C at a heating rate of 100°C/min, Then vacuum sintering at 800°C for 0.5h. After sintering, it was naturally cooled to room temperature under a load pressure of 0MPa to obtain a Si _{1-x Gex} M _y block, where M is Mn or Fe.

According to a preferred embodiment, the silicon powder is silicon powder with a mass fraction of silicon greater than 99.99%; the germanium powder is germanium powder with a mass fraction of germanium greater than 99.99%; the manganese powder is a mass fraction of manganese Manganese powder with a fraction greater than 99.8%; the iron powder is an iron powder with an iron mass fraction greater than 99.9%.

According to a preferred embodiment, in step S2, the ball milling time is 1 h.

According to a preferred embodiment, in step S3, the drying temperature is 50° C., and the drying time is 10 h.

According to a preferred implementation manner, in step S4, 0.7≤x≤0.8, y≤0.08.

According to a preferred embodiment, in step S4, x=0.75, y=0.03, 0.05 or 0.08.

The invention also provides a bulk room temperature ferromagnetic Si _{1-x Gex My} semiconductor, the Si _1-x Ge _{x My} semiconductor is prepared by the preparation method.

According to a preferred embodiment, the Curie temperature of the bulk room temperature ferromagnetic Si _{1-x Gex My} semiconductor can reach 300K at the highest.

The invention also provides the application of the bulk room temperature ferromagnetic Si _{1-x Gex} My _y semiconductor in the field of magnetic semiconductors.

Based on the above technical scheme, a bulk room temperature ferromagnetic Si _{1-x Gex} M _y semiconductor, preparation method and application thereof of the present invention at least have the following technical effects:

The preparation method of bulk room temperature ferromagnetic Si _1-x Ge _x My _y semiconductor of the present invention adopts planetary ball mill to ball mill agate balls, silicon powder, germanium powder and manganese powder or iron powder to obtain mixed powder, and then adopts discharge plasma sintering The method of sintering the mixed powder to obtain the Si _{1-x Gex} My _y block can quickly prepare the bulk Si _{1-x Gex My} semiconductor, and has the advantages of simple operation process, high output and low cost.

The bulk room temperature ferromagnetic Si _{1-x Gex My} semiconductor prepared by the preparation method of the present invention has a uniform manganese or iron doping distribution, and its Curie temperature increases with the increase of manganese or iron content, the highest Can reach room temperature 300K.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the physical picture of the Si _0.25 Ge _0.75 Mn _0.08 block prepared in Example 4 of the present invention, the X-ray diffraction characterization diagram of the bulk Si _1-x Ge _x Mn _y semiconductor prepared in Examples 1 to 4, and the implementation The high-angle annular dark field image and the corresponding element distribution diagram of the Si _0.25 Ge _0.75 Mn _0.08 block obtained in Example 4 under the spherical aberration transmission electron microscope scanning mode;

Fig. 2 is the graph showing the variation of magnetic moments of the bulk Si _1-x Ge _x Mn _y semiconductors prepared in Examples 1 to 4 with temperature and the Si _0.25 Ge _0.75 Mn _0.08 bulk prepared in Example 4 at different temperatures Hysteresis loop;

Fig. 3 is the X-ray diffraction characterization diagram of the bulk Si _1-x Ge _x Fe _y semiconductors prepared in Examples 1, 5 to 7, and the bulk Si _1-x Ge _x Fe _y semiconductors prepared in Examples 5 to 7 The variation diagram of the magnetic moment with temperature and the hysteresis loops of the Si _0.25 Ge _0.75 Fe _0.08 bulk prepared in Example 7 at different temperatures.

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Apparently, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other implementations obtained by persons of ordinary skill in the art without making creative efforts fall within the protection scope of the present invention.

Example 1

The present embodiment 1 provides a kind of preparation method of bulk Si _{1-x Gex} , comprises the following steps:

S1: Add agate balls, silicon powder and germanium powder into an agate ball mill tank containing absolute ethanol, so that the mass ratio of balls to materials is 8:1; among them, the mass ratio of silicon powder to germanium powder is 1:7.76;

S2: put the above-mentioned agate ball mill jar into a planetary ball mill at a speed of 200r/min, and ball mill for 1 hour;

S3: put the mixed powder containing absolute ethanol after ball milling into a vacuum drying oven, and dry at 50° C. for 10 hours to obtain a dried mixed powder;

S4: Put the dry mixed powder into a graphite mold and use spark plasma sintering. The spark plasma sintering conditions are: under a load pressure of 50MPa, heat to 800°C at a heating rate of 100°C/min, and then Vacuum sintering at high temperature for 0.5h, and naturally cooled to room temperature under a load pressure of 0MPa after sintering to obtain a Si _0.25 Ge _0.75 block.

Example 2

This embodiment provides a method for preparing a bulk ferromagnetic Si _1-x Ge _x Mn _y semiconductor, comprising the following steps:

S1: Add agate balls, silicon powder, germanium powder and manganese powder into an agate ball mill tank containing absolute ethanol, so that the mass ratio of balls to materials is 8:1; among them, the mass ratio of silicon powder, germanium powder and manganese powder is 1:7.76:0.24;

S2: put the above-mentioned agate ball mill jar into a planetary ball mill at a speed of 200r/min, and ball mill for 1 hour;

S3: put the mixed powder containing absolute ethanol after ball milling into a vacuum drying oven at 50° C. for 10 hours to obtain a dried mixed powder;

S4: Put the dry mixed powder into a graphite mold and use spark plasma sintering. The spark plasma sintering conditions are: under a load pressure of 50MPa, heat to 800°C at a heating rate of 100°C/min, and then Sintering under vacuum for 0.5h, and then naturally cooling to room temperature under a load pressure of 0MPa after sintering to obtain a Si _0.25 Ge _0.75 Mn _0.03 block.

Example 3

This embodiment provides yet another method for preparing a bulk ferromagnetic Si _1-x Ge _x Mn _y semiconductor, comprising the following steps:

S1: Add agate balls, silicon powder, germanium powder and manganese powder into an agate ball mill tank containing absolute ethanol, so that the mass ratio of balls to materials is 8:1; among them, the mass ratio of silicon powder, germanium powder and manganese powder is 1:7.76:0.41;

S2: put the above-mentioned agate ball mill jar into a planetary ball mill at a speed of 200r/min, and ball mill for 1 hour;

S3: put the mixed powder containing absolute ethanol after ball milling into a vacuum drying oven at 50° C. for 10 hours to obtain a dried mixed powder;

S4: Put the dry mixed powder into a graphite mold and use spark plasma sintering. The spark plasma sintering conditions are: under a load pressure of 50MPa, heat to 800°C at a heating rate of 100°C/min, and then Sintering under vacuum for 0.5h, and then naturally cooling to room temperature under a load pressure of 0MPa after sintering to obtain a Si _0.25 Ge _0.75 Mn _0.05 block.

Example 4

This embodiment provides yet another method for preparing a bulk ferromagnetic Si _1-x Ge _x Mn _y semiconductor, comprising the following steps:

S1: Add agate balls, silicon powder, germanium powder and manganese powder into an agate ball mill tank containing absolute ethanol, so that the mass ratio of balls to materials is 8:1; wherein, the mass ratio of silicon powder, germanium powder and manganese powder is 1:7.76:0.68;

S2: put the above-mentioned agate ball mill jar into a planetary ball mill at a speed of 200r/min, and ball mill for 1 hour;

S3: put the mixed powder containing absolute ethanol after ball milling into a vacuum drying oven at 50° C. for 10 hours to obtain a dried mixed powder;

S4: Put the dry mixed powder into a graphite mold and use spark plasma sintering. The spark plasma sintering conditions are: under a load pressure of 50MPa, heat to 800°C at a heating rate of 100°C/min, and then Vacuum sintering at high temperature for 0.5h, and naturally cooled to room temperature under a load pressure of 0MPa after sintering to obtain a Si _0.25 Ge _0.75 Mn _0.08 block.

Example 5

This embodiment provides a method for preparing a bulk ferromagnetic Si _{1-x Gex} Fe _y semiconductor, comprising the following steps:

S1: Add agate balls, silicon powder, germanium powder and iron powder into an agate ball mill tank containing absolute ethanol, so that the mass ratio of balls to materials is 8:1; among them, the mass ratio of silicon powder, germanium powder and iron powder For: 1:7.76:0.25;

S2: put the above-mentioned agate ball mill jar into a planetary ball mill at a speed of 200r/min, and ball mill for 1 hour;

S3: put the mixed powder containing absolute ethanol after ball milling into a vacuum drying oven at 50° C. for 10 hours to obtain a dried mixed powder;

S4: Put the dry mixed powder into a graphite mold and use spark plasma sintering. The spark plasma sintering conditions are: under a load pressure of 50MPa, heat to 800°C at a heating rate of 100°C/min, and then Vacuum sintering at high temperature for 0.5h, and naturally cooled to room temperature under a load pressure of 0MPa after sintering to obtain a Si _0.25 Ge _0.75 Fe _0.03 block.

Example 6

This embodiment provides yet another method for preparing a bulk ferromagnetic Si _{1-x Gex} Fe _y semiconductor, comprising the following steps:

S1: Add agate balls, silicon powder, germanium powder and iron powder into an agate ball mill tank containing absolute ethanol, so that the mass ratio of balls to materials is 8:1; among them, the mass ratio of silicon powder, germanium powder and iron powder For: 1:7.76:0.42;

S2: put the above-mentioned agate ball mill jar into a planetary ball mill at a speed of 200r/min, and ball mill for 1 hour;

S3: put the mixed powder containing absolute ethanol after ball milling into a vacuum drying oven at 50° C. for 10 hours to obtain a dried mixed powder;

S4: Put the dry mixed powder into a graphite mold and use spark plasma sintering. The spark plasma sintering conditions are: under a load pressure of 50MPa, heat to 800°C at a heating rate of 100°C/min, and then Vacuum sintering at high temperature for 0.5h, and naturally cooling to room temperature under a load pressure of 0MPa after sintering to obtain a Si _0.25 Ge _0.75 Fe _0.05 block.

Example 7

This embodiment provides yet another method for preparing a bulk ferromagnetic Si _{1-x Gex} Fe _y semiconductor, comprising the following steps:

S1: Add agate balls, silicon powder, germanium powder and iron powder into an agate ball mill tank containing absolute ethanol, so that the mass ratio of balls to materials is 8:1; among them, the mass ratio of silicon powder, germanium powder and iron powder For: 1:7.76:0.69;

S2: put the above-mentioned agate ball mill jar into a planetary ball mill at a speed of 200r/min, and ball mill for 1 hour;

S3: put the mixed powder containing absolute ethanol after ball milling into a vacuum drying oven at 50° C. for 10 hours to obtain a dried mixed powder;

S4: Put the dry mixed powder into a graphite mold and use spark plasma sintering. The spark plasma sintering conditions are: under a load pressure of 50MPa, heat to 800°C at a heating rate of 100°C/min, and then Vacuum sintering at high temperature for 0.5h, and naturally cooled to room temperature under a load pressure of 0MPa after sintering to obtain a Si _0.25 Ge _0.75 Fe _0.08 block.

The results are shown in Figures 1 to 3, and Figures 1 to 3 show the pictures obtained by characterizing the Si _{1-x Gex} M _y blocks obtained in Examples 1 to 7, wherein M is Mn or Fe . in:

Referring to Fig. 1, (a) in Fig. 1 is the physical map of the Si _0.25 Ge _0.75 Mn _0.08 block obtained in Example 4; (b) is the bulk Si ₁ prepared in Examples 1, 2, 3 and 4 _-X -ray diffraction characterization diagram of xGe _x Mn _y semiconductor; (c) The picture shows the high-angle annular dark field image of the Si _0.25 Ge _0.75 Mn _0.08 bulk obtained in Example 4 under the spherical aberration transmission electron microscope scanning mode and the corresponding elements Distribution. It can be seen from Fig. 1 that a polycrystalline Si _1-x Ge _x Mn _y block with good crystallinity can be prepared by the preparation method of the present invention, and the silicon, germanium, and manganese elements in the Si _1-x Ge _x Mn _y block The distribution is uniform, and no manganese element aggregation is found. Therefore, the preparation method of the present invention can increase the solubility of the Mn metal element in the silicon-germanium alloy lattice, and avoid the phenomenon of Mn precipitation and aggregation in the silicon-germanium alloy.

Referring to Fig. 2, (a) figure in Fig. 2 is the magnetic moment of the bulk Si _1-x Ge _x Mn _y semiconductor that embodiment 1, 2, 3 and 4 gains varies with temperature, as seen from Fig. 2 (a) , increasing the doping concentration of Mn can effectively increase the Curie temperature of Si _1-x Ge _x Mn _y semiconductor, and the Curie temperature can reach 300K. Fig. 2(b) shows the hysteresis loop tests of the Si _0.25 Ge _0.75 Mn _0.08 block obtained in Example 4 at different temperatures, and it can be seen that it still has ferromagnetism at room temperature at 300K. Therefore, the Si _{1-x Gex} M _y block prepared by the preparation method of the present invention, wherein M is Mn or Fe, has a relatively high Curie temperature and ferromagnetism at room temperature, and the Curie temperature can reach up to 300K at room temperature.

With reference to Fig. 3, among Fig. 3 (a) figure is example 1,5,6 and 7 bulk Si _1-x Ge _x Fe _y semiconductor's X-ray diffraction characterization figure of semiconductor, Fig. 3 (a) shows that by the present invention The preparation method can prepare polycrystalline Si _{1-x Gex} Fe _y blocks with good crystallinity. Fig. 3 (b) figure is the magnetic moment of the bulk Si _1-x Ge _x Fe _y semiconductor obtained in Examples 5, 6 and 7 varies with temperature. From Fig. 3 (b), it can be concluded that increasing the Fe doping concentration The Curie temperature of the Si _1-x Ge _x Fe _y semiconductor can be effectively increased, and the Curie temperature can reach 266K. Fig. 3(c) shows the hysteresis loop test of the Si _0.25 Ge _0.75 Fe _0.08 block obtained in Example 7 at different temperatures.

The present inventors considered the spark plasma sintering method because its high pulse current, high voltage and fast sintering rate can result in high densification and high uniformity of the synthesized alloy. Simultaneous spark plasma sintering is a non-equilibrium process, which is beneficial to increase the solubility of transition metal element dopants in the group IV lattice (>>equilibrium solubility), thus enhancing the ferromagnetism of the synthesized alloy. The invention can quickly prepare bulk room temperature ferromagnetic Si _{1-x Gex My} (M is Mn or Fe) semiconductor by adopting the method of planetary ball mill combined with discharge plasma sintering, and has simple operation process, high yield and low cost. The bulk room temperature ferromagnetic Si _{1-x Gex My} (M is Mn or Fe) semiconductor prepared by the preparation method of the present invention has uniform manganese or iron doping distribution, and its Curie temperature increases with the content of manganese or iron The concentration increases and increases, up to room temperature 300K.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (9)

1. Block-shaped room-temperature ferromagnetism Si _1-x Ge _x M _y The preparation method of the semiconductor is characterized by comprising the following steps:

s1: adding agate balls, silicon powder, germanium powder and manganese powder or iron powder into an agate ball milling tank containing absolute ethyl alcohol, wherein the mass ratio of the balls to the materials is 8:1, a step of;

s2: placing the agate ball milling tank into a planetary ball mill to perform ball milling at a rotating speed of 200 r/min;

s3: placing the ball-milled mixed powder containing absolute ethyl alcohol into a vacuum drying oven for drying to obtain dried mixed powder;

s4: placing the dried mixed powder in the step S3 into a graphite mold, and sintering by using discharge plasma, wherein the discharge plasma sintering conditions are as follows: heating to 800 ℃ at a heating rate of 100 ℃/min under a load pressure of 50MPa, then vacuum sintering at 800 ℃ for 0.5h, and naturally cooling to room temperature under a load pressure of 0MPa after sintering to obtain Si _1-x Ge _x M _y The block, wherein M is Mn or Fe, and y is more than or equal to 0.03 and less than or equal to 0.08.

2. The preparation method of claim 1, wherein the silicon powder is silicon powder with a mass fraction of silicon greater than 99.99%; the germanium powder is germanium powder with the mass fraction of germanium being more than 99.99%; the manganese powder is manganese powder with the mass fraction of manganese being more than 99.8%; the iron powder is iron powder with the mass fraction of iron being more than 99.9%.

3. The method according to claim 1, wherein in step S2, the ball milling time is 1h.

4. The method according to claim 1, wherein in step S3, the drying temperature is 50 ℃ and the drying time is 10 hours.

5. The method according to claim 1, wherein 0.7.ltoreq.x.ltoreq.0.8 in step S4.

6. The method according to claim 5, wherein in step S4, x=0.75, y=0.03, 0.05 or 0.08.

7. Block-shaped room-temperature ferromagnetism Si _1-x Ge _x M _y A semiconductor, characterized in that the Si _1-x Ge _x M _y The semiconductor is prepared by the preparation method as claimed in any one of claims 1 to 6.

8. Bulk room temperature ferromagnetic Si as recited in claim 7 _1-x Ge _x M _y The semiconductor is characterized in that the bulk room temperature ferromagnetism Si _1-x Ge _x M _y The curie temperature of the semiconductor can reach 300K at the highest.

9. Bulk room temperature ferromagnetic Si as claimed in claim 7 or 8 _1-x Ge _x M _y Application of semiconductors in the field of magnetic semiconductors.

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