CN108624852B

CN108624852B - high-Curie-temperature Fe-Zr amorphous multilayer film and preparation method thereof

Info

Publication number: CN108624852B
Application number: CN201710153336.5A
Authority: CN
Inventors: 孙铭; 吴斌; 冯涛; 彭国
Original assignee: Nanjing University of Science and Technology
Current assignee: Nanjing University of Science and Technology
Priority date: 2017-03-15
Filing date: 2017-03-15
Publication date: 2020-04-10
Anticipated expiration: 2037-03-15
Also published as: CN108624852A

Abstract

The invention discloses an iron-zirconium amorphous multilayer film with high Curie temperature and a preparation method thereof. The amorphous multilayer film is Fe₇₅Zr₂₅/Cu₆₄Zr₃₆The material has a single layer thickness of 10nm and has 50 layers. The amorphous alloy has the advantages of a FeZr single-layer film material, has a higher Curie temperature which is higher than 300K of room temperature, is the best performance achieved by the existing FeZr amorphous system, and can realize the wide application of the FeZr system.

Description

high-Curie-temperature Fe-Zr amorphous multilayer film and preparation method thereof

Technical Field

The invention belongs to the field of amorphous alloy, and particularly relates to an iron-based amorphous multilayer film alloy with Curie temperature higher than room temperature and good applicability and a preparation method thereof.

Background

Amorphous alloys are a class of alloy materials with short-range order, long-range disordered structures. The atoms in the amorphous are arranged in disorder, and defects such as vacancies, dislocations, grain boundaries, and faults in the crystalline metal do not exist. The amorphous unique structural characteristics bring unique performance performances such as high catalytic activation, excellent biocompatibility, excellent soft magnetism, high strength, high hardness and the like.

The amorphous multilayer film material has a more complex interface structure, which plays an important role in changing and improving the performance. Amorphous multilayer film materials have been used in a variety of fields due to their excellent magnetic, mechanical, and photoelectric properties. For example, Fe/Cr nano-multilayer films exhibit a giant magnetoresistance effect in an external magnetic field, and are expected to be promising materials in the field of information storage.

Amorphous alloy materials have been most developed as a field of soft magnetic materials. The amorphous material has lower coercive force and higher magnetic permeability due to disordered arrangement of atoms in the amorphous material and no pinning effect of crystal boundary and second-term particles on a domain wall. The feazr amorphous alloy material has become a hot spot of current research due to its own superconductivity, ferromagnetism, spin glass, and antiferromagnetism. However, the traditional FeZr amorphous alloy has a low Curie temperature of about 200K, which is lower than room temperature, and limits the application of the FeZr amorphous alloy in small devices and room temperature, and in order to solve the problems, it is very important to develop a FeZr system amorphous alloy with a high Curie temperature.

Disclosure of Invention

The invention aims to provide an iron-zirconium amorphous multilayer film with high Curie temperature and a preparation method thereof, aiming at the technical analysis and problems.

The technical scheme for realizing the purpose of the invention is as follows: an Fe-Zr amorphous multilayer film with high Curie temperature contains Fe₇₅Zr₂₅/Cu₆₄Zr₃₆Each single layer film had a thickness of 10nm and the number of layers was 50.

Said Fe₇₅Zr₂₅/Cu₆₄Zr₃₆The Curie temperature of the amorphous multilayer film is more than 300K.

The preparation method of the multilayer film material comprises the following steps:

(1) select Fe₇₅Zr₂₅、Cu₆₄Zr₃₆An alloy target is selected from clean Si (111) sheetThe wafer is used as a substrate, high-purity argon is used as working gas, and nitrogen is used as drying gas of the cavity;

(2) during sputtering, the vacuum is pre-pumped to 1 x 10^-4And introducing argon below Pa to enable the pressure to reach 0.5Pa, controlling the sputtering power of the target material to be 30W, and controlling the growth thickness of each single-layer film to be 10nm and the growth layer number to be 50.

Further, in the step (2), by controlling Fe₇₅Zr₂₅The sputtering time of the alloy target was 400s, Cu₆₄Zr₃₆The sputtering time of the alloy target was 150 seconds, the number of cycles was 25, the growth thickness of each single layer film was controlled to 10nm, and the number of layers grown was 50.

Compared with the prior art, the invention has the advantages that:

the amorphous alloy prepared by the method has excellent soft magnetic performance, the Curie temperature is higher than 300K, and the Curie temperature of the FeZr amorphous alloy system reported at present is about 200K.

Drawings

FIG. 1 shows Fe obtained in example 1₇₅Zr₂₅/Cu₆₄Zr₃₆SEM image of actual thickness cross section of the multilayer film.

FIG. 2 shows Fe obtained in example 1₇₅Zr₂₅/Cu₆₄Zr₃₆Actual XRD pattern of multilayer film.

FIG. 3 shows Fe obtained in example 1₇₅Zr₂₅/Cu₆₄Zr₃₆ZFC-FC curves for multilayer films.

FIG. 4 shows Fe obtained in example 1₇₅Zr₂₅/Cu₆₄Zr₃₆M-H curve of multilayer film (a is at 4K temperature)

M-H curve, b is M-H curve at 300K temperature).

Detailed Description

The invention is described in further detail below with reference to the figures and examples.

Examples 1

This example uses magnetron sputtering to produce Fe₇₅Zr₂₅/Cu₆₄Zr₃₆Amorphous multilayer film and X-ray diffractometerAnd performing structural characterization on the scanning electron microscope, and performing magnetic test on the comprehensive physical property measurement system.

(1) Select Fe₇₅Zr₂₅Alloy target, Cu₆₄Zr₃₆The alloy target has a target thickness of 3mm and a target diameter of 50 mm. A clean Si (111) single crystal wafer is selected as a substrate, high-purity argon is used as a working gas, and nitrogen is used as a drying gas of a cavity.

(2) During sputtering, the vacuum is pre-pumped to 1 x 10^-4Below Pa, argon gas was introduced so that the pressure reached 0.5 Pa. Sputtering power of the target material is 30W, and single-layer Fe is respectively prepared₇₅Zr₂₅Thin film, Cu₆₄Zr₃₆Film thickness by SEM observation, 2 hours coating time, Fe₇₅Zr₂₅Film thickness of 180nm, Cu₆₄Zr₃₆The thickness of the film is 480nm, and the growth rate of the film is obtained.

(3) Preparation of 10nm monolayer thickness of Fe₇₅Zr₂₅/Cu₆₄Zr₃₆The multilayer film is programmed by using a computer control system, so that the control of the switching time and the cycle number of each target material is realized, and specific parameters are shown in table 1.

TABLE 1 coating Process parameters

The amorphous structure of the film is characterized by XRD, the test result is shown in figure 1, and only one wide diffuse scattering peak exists on the XRD spectrum of the sample, so that the film has a better amorphous structure. And the thickness and composition of the film were measured using SEM-EDS, and the results of the tests are shown in fig. 2 and table 2, and it was found that multilayer film materials having relatively uniform composition and very close thickness were prepared.

TABLE 2 Fe₇₅Zr₂₅/Cu₆₄Zr₃₆Component ratio of multilayer film

FeZr/CuZr	Fe(at％)	Cu(at％)	Zr(at％)	Ta(at％)	Fe:Cu(at)
						10nm	41	28	30	1	1.5:1

(4) The magnetism of the multilayer film is measured by using a comprehensive physical property measurement system, the test result of a ZFC-FC curve is shown in figure 3, and the test result of an M-H curve is shown in figure 4. The Curie temperature of the multilayer film material is obviously higher than 300K, and the saturation magnetization at 4K is 0.75 mu_BThe saturation intensity at 300K is 0.58 mu_B。

Comparative example 1

This example uses magnetron sputtering to produce Fe₇₅Zr₂₅And carrying out structural characterization on the amorphous single-layer film by using an X-ray diffractometer and a scanning electron microscope, and carrying out magnetic test on the comprehensive physical property measurement system.

(1) Select Fe₇₅Zr₂₅The alloy target has the target thickness of 3mm and the target diameter of 50mm, a clean Si (111) single crystal wafer is selected as a substrate, high-purity argon is used as a working gas, and nitrogen is used as a drying gas of a chamber.

(2) During sputtering, the vacuum is pre-pumped to 1 x 10^-4Below Pa, argon gas was introduced so that the pressure reached 0.5 Pa. The sputtering power of the target material is 30W, and the Fe with the single-layer thickness of 250nm is prepared₇₅Zr₂₅A film.

(3) The structure of the sample is characterized by an X-ray diffraction method, and the result shows that only one wide diffuse scattering peak exists on the XRD spectrum of the sample, and the sample has a better amorphous structure. And the thickness and composition of the film were measured using SEM-EDS to find that the sample composition was relatively uniform, with a thickness of about 250 nm.

(4) The magnetism of the multilayer film is measured by using an integrated physical property measuring system, and the M-H curve and the ZFC curve are included. The results show Fe₇₅Zr₂₅The amorphous monolayer film has a saturation magnetization close to that of the multilayer film, but has a Curie temperature of about 200K, which is lower than room temperature.

Comparative example 2

Comparative example 2 used an amorphous multilayer film material of Fe90Zr10/Al75Zr25 in the Finite-size efficiencies in Amorphous Fe90Zr10/Al75Zr25 multilayers, P.T. Korelis et Al, PHYSICAL REVIEW B,85,214430(2012), also analyzed for Curie temperature and saturation magnetization, and found that the multilayer film material had Curie temperatures below 200K.

Claims

1. The Fe-Zr amorphous multilayer film with high Curie temperature is characterized in that the component is Fe₇₅Zr₂₅/Cu₆₄Zr₃₆Each single layer film had a thickness of 10nm and the number of layers was 50.

2. The Fe-Zr amorphous multilayer film according to claim 1, wherein said Fe is Fe₇₅Zr₂₅/Cu₆₄Zr₃₆The Curie temperature of the amorphous multilayer film is more than 300K.

3. The method for producing an iron-zirconium amorphous multilayer film according to claim 1 or 2, characterized by comprising the steps of:

(1) select Fe₇₅Zr₂₅、Cu₆₄Zr₃₆Alloy target, clean Si (1)11) The single chip is used as a substrate, high-purity argon is used as working gas, and nitrogen is used as drying gas of a cavity;

4. The method of claim 3, wherein in step (2), Fe is controlled₇₅Zr₂₅The sputtering time of the alloy target was 400s, Cu₆₄Zr₃₆The sputtering time of the alloy target was 150 seconds, the number of cycles was 25, the growth thickness of each single layer film was controlled to 10nm, and the number of layers grown was 50.