JPH0696947A - Thin belt-like iron nitride material - Google Patents

Abstract

(57) [Summary] [Structure] In order to produce Fe ₁₆ N ₂ having a large area and film thickness,
Fe is vapor-deposited while rotating the flexible substrate in the vapor deposition device.
An iron nitride film having a film thickness of 100 nm or more is vapor-deposited thereon and heat-treated at 200 ° C. to precipitate Fe ₁₆ N ₂ in the film to increase the saturation magnetic flux density. [Effect] It is possible to obtain a tape-like material in which a material having a maximum saturation magnetic flux density of 2.8 T is formed on a flexible substrate. As a result, Fe ₁₆ N ₂ can be used for the core of a transformer or the like.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a high saturation magnetic flux density material Fe.
_The present invention relates to a method for producing iron nitride containing ₁₆ N ₂ in a ribbon shape, and a ribbon-shaped iron nitride material produced by this method.

[0002]

2. Description of the Related Art Iron nitride Fe ₁₆ N ₂ is N ₂ or N ₂ +
It is produced in a single-phase and single-crystal state by vapor deposition in a high vacuum vapor deposition apparatus in an NH ₃ atmosphere, and has a saturation magnetic flux density of 2.8.
It is known to have the maximum saturation magnetic flux density of T-3.0T among existing materials. However, this direct growth or lattice constant to 6.058Å or less on the substrate over 5.653Å in InGaAs-based, Fe ₁₆ N from after depositing the Fe in the base
₂ can be produced. Manufacturable Fe
_{The 16} N ₂ film had a film thickness of about 100 nm and a size of about 2 inches in diameter, and was not suitable for practical use as a transformer material or a magnet material. The reason for this is that Fe ₁₆ N ₂ is very sensitive to the substrate, film growth rate, temperature, and atmosphere, and is extremely difficult to manufacture. Also, in a general vapor deposition apparatus, since the region where the growth rate of the substance to be vapor deposited is constant is limited, the substrate is fixed at one position in the vapor deposition chamber during vapor deposition.

This iron nitride is disclosed in JP-A-59-65911.
Japanese Patent Laid-Open Publication No. 2003-242242 discloses an iron nitride containing 10% or more of Fe ₁₆ N ₂ produced by sputtering in a nitrogen-containing atmosphere.

[0004]

The greatest feature of the present invention is that it uses a flexible material for the substrate and the thickness of the iron nitride produced is 100 nm or more, which is not an obstacle. The present invention enables a tape-like Fe ₁₆ N ₂ thin film having an unprecedented high saturation magnetic flux density to be produced by selecting the type of substrate and a method of fixing the substrate in a vapor deposition chamber, and The present invention aims to provide an electromagnet having an increased saturation magnetic field of a magnetic pole, a transformer having a reduced eddy current loss, and other practically effective application examples.

[0005]

In order to achieve the above-mentioned object, the present invention uses a flexible ceramic or polymer material as a substrate as shown in FIG. With this substrate fixed, this drum is rotated to deposit Fe. After that, N ₂ or N ₂ + NH
We devise a production method that enables the production of tape-like Fe ₁₆ N ₂ samples by growing Fe ₁₆ N ₂ on Fe in ₃ atmospheres.

The electric resistivity of Fe ₁₆ N ₂ is about three times higher than that of Fe at room temperature. Further, the hysteresis loss is almost the same as that of Fe, and it is considered that it is effective as a core material having a small eddy current loss for low-frequency alternating current.

Further, the tape-like Fe ₁₆ N ₂ produced by this production method is cut into an appropriate size, and the sheets are superposed and joined to each other, whereby the shape of the core of the transformer can be obtained.

[0008]

[Operation] By using a high saturation magnetic flux density Fe ₁₆ N ₂ ,
It can be used as a core material that is less likely to saturate up to a larger magnetic field than conventional materials.

[0009]

EXAMPLES An example of the present invention will be described below.
First, as the substrate, a flexible substrate made of YSZ or a ceramic such as polyimide or a polymer is used. Figure 2
The substrate holder 21 shown in FIG. A rod is screwed to the portion of this substrate holder at 25, and the substrate holder is introduced into the vacuum chamber shown in FIG. The drum 22 can be rotated in the vapor deposition tank via a gear 26. The substrate is roll-shaped, tape-shaped, or plate-shaped and can be fixed to the substrate holder. The vapor deposition apparatus has the configuration shown in FIG. 3, and the ultimate vacuum in the vapor deposition tank is 10 ⁻⁶ Pa or less. There are two electron beams 32 and 33 in the figure, 32 is used as a vapor deposition source, and 33 is used for thermal dissociation of gas. The evaporation source is 99.999% Fe.

First, the substrate holder is rotated to bring the substrate temperature to 30
Fe at 10 to 50 n at 0 ° C. and vapor deposition rate of 0.01 nm / sec
m vapor deposition. The film thickness is examined during film formation using a crystal oscillation type film thickness meter 37 shown in FIG. The amount of N in the film is X after the film is formed.
It is measured by line photoelectron spectroscopy. According to this, the saturation magnetic flux density with respect to the amount of N becomes as shown in FIG. Therefore, the sample having a saturation magnetic flux density higher than 2.5T needs to have an N content of 7% or more and 11% or less. Here, the amount of N with respect to the gas pressure is as shown in FIG. From now on, N
In order to reach the amount, after Fe deposition, N ₂ or N
₂ + NH ₃ gas is introduced in the range of 10 ^-3 Pa or more and 10 ^-1 Pa or less. At this time, especially in the vicinity of 1.4 × 10 ^-2 Pa, Fe
The N concentration in the inside becomes 11 at%. The substrate temperature is
250 ° C is suitable. During vapor deposition, the atmospheric gas is dissociated by adjusting the electric current applied to the electron beam for thermal dissociation.
The dissociated state is measured by a quadrupole mass spectrometer shown at 35 in FIG. Fe ₁₆ N ₂ is grown on the Fe film at a deposition rate of 0.01 nm / sec or more to a film thickness of about 100 to 1000 nm. The tape-shaped sample prepared in this manner was used for 10 ^-2
Heat treatment is performed at 200 ° C. for 8 hours or more in a vacuum chamber of Pa or less. As shown in FIG. 7, the saturation magnetic flux density changes depending on the annealing time. Furthermore, the temperature range X-ray heat treatment temperature than the diffraction following 300 ° C. 0.99 ° C. or higher in FIG. 8 Fe ₁₆ N
Generation of ₂ can be seen. Fe-N produced in this way
The film has a thickness of 10 when measured by a stylus type film thickness meter.
It is 0 nm or more, the magnetic measurement by the sample vibrating magnetometer (VSM) has the magnetization curve shown in FIG. 9, and the saturation magnetic flux density is 2.2T or more and 2.8T or less. From this fact and the result of X-ray diffraction, it is understood that Fe ₁₆ N ₂ is generated in the sample by the heat treatment. Furthermore, when the electric resistance of this film was measured, as shown in FIG. 10, it showed an electric resistivity of not less than 1.5 × 10 ⁻⁵ Ωcm and not more than 4.0 × 10 ⁻⁵ Ωcm, which is effective in reducing eddy current loss. is there.

The sample thus produced has a tape-like shape. This is cut into an appropriate shape, and several tens to several hundreds are stacked and bonded with a resin or the like to form a plate-shaped material. This material can be used as a core material such as the 111 part of the transformer as shown in FIG. 11 and the 121 part of the electromagnet as shown in FIG.

[0012]

According to the present invention, an iron-nitrogen compound ribbon having a high saturation magnetic flux density and a good eddy current reduction characteristic can be obtained.

[Brief description of drawings]

FIG. 1 is an explanatory view of a ribbon-shaped iron nitride material produced by the present invention.

FIG. 2 is a perspective view of a substrate holder used in the present invention.

FIG. 3 is an explanatory diagram of a vapor deposition device used in the present invention.

FIG. 4 is a characteristic diagram of nitrogen content dependency of saturation magnetic flux density of iron nitride.

FIG. 5 is a characteristic diagram of the gas pressure dependency during deposition of the nitrogen content of iron nitride.

FIG. 6 is a characteristic diagram of substrate temperature dependence of saturation magnetic flux density of iron nitride.

FIG. 7 is a characteristic diagram of annealing time dependency of saturation magnetic flux density of iron nitride.

FIG. 8 is an explanatory view of a change in annealing temperature of X-ray diffraction of iron nitride.

FIG. 9 is a magnetization characteristic diagram of iron nitride.

FIG. 10 is an explanatory diagram of N concentration dependence of resistance of iron nitride.

FIG. 11 is a sectional view of a transformer using a tape-shaped iron nitride film.

FIG. 12 is a sectional view of an electromagnet using a tape-shaped iron nitride film.

[Explanation of symbols]

11 ... Sheet-shaped iron nitride material, 12, 13, 14 ... Cross-sectional view of this sample, 12 ... Fe _95-88 N _5-12 film, 13 ... Fe
Membrane, 14 ... Flexible substrate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Hoshiya 4026 Kuji Town, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi, Ltd.

Claims (3)

[Claims] 1. An iron nitride Fe-N containing N at 5.0 at% or more and 12.0 at% or less and having a film thickness of 100 nm or more is grown on an Fe film, and heat treated at 150 ° C. or more and 350 ° C. or less to produce Fe. _A strip-shaped iron nitride material produced by a method of solid-phase growing ₁₆ N ₂ and having a saturation magnetic flux density of 2.2 T or more and 2.8 T or less. 2. The roll-shaped, tape-shaped or flat-shaped flexible substrate according to claim 1, which is fixed to a drum in a vapor deposition apparatus, and Fe is vapor-deposited on the flexible substrate in vacuum.
_A method for producing a strip-shaped iron nitride material in which Fe-N is grown while rotating a drum in a ₂ or NH ₃ + N ₂ atmosphere. 3. The material as set forth in claim 1, which has an electric resistivity of 1.5 × 10 ⁻⁵ Ωcm or more and 7.0 at room temperature.
A strip-shaped iron nitride material having a density of less than × 10 ^-5 Ωcm.