A planar anisotropic rare earth-based high-frequency soft magnetic film and its preparation method

Abstract

The present invention belongs to the technical field of soft magnetic film materials, and relates to a planar anisotropic rare earth-based high-frequency soft magnetic film and a preparation method thereof. The rare earth-based high-frequency soft magnetic film is composed of RE2TM 17 , wherein RE is a rare earth element and TM is a transition metal element; the preparation method comprises the following steps: depositing a rare earth-transition metal film on a substrate, and then preparing RE2TM by vacuum annealing. 17 Soft magnetic film. This invention breaks through the Acher limit of soft magnetic film and the composition obtained is RE2TM 17 The planar anisotropic rare earth-based high-frequency soft magnetic film improves the natural resonance frequency without sacrificing magnetic permeability.

Description

Technical Field

[0001] The invention belongs to the technical field of soft magnetic film materials and relates to a planar anisotropic rare earth-based high-frequency soft magnetic film and a preparation method thereof. Background Art

[0002] Soft magnetic materials refer to magnetic materials that are easy to magnetize and demagnetize under a weak external magnetic field. + High-frequency technologies such as microinductors, noise suppressors, and magnetic recording have important applications in fields like communications. With the increasing density of information storage, data transmission rates, and processing frequencies, as well as the advancement of device integration, high-frequency and miniaturization are essential development trends, placing higher demands on high-frequency soft magnetic film materials. Currently, the widely studied Fe- and Co-based soft magnetic films exhibit microwave magnetism that follows the Acher limit due to the out-of-plane anisotropy field being equal to the demagnetization field. Increasing the natural resonant frequency of the film necessarily requires increasing the saturation magnetization, while sacrificing microwave permeability. Improving the high-frequency performance of soft magnetic films solely by increasing the saturation magnetization is clearly not the optimal solution, and therefore cannot meet the demands of the high-frequency and miniaturization of electronic devices. Therefore, the research and development of new soft magnetic film materials with excellent comprehensive high-frequency magnetic properties is a critical scientific challenge for GHz-band applications.

[0003] According to the bi-anisotropy model proposed by Xue Desheng and others, for magnetic thin film materials with planar anisotropy, such as rare earth-transition metal soft magnetics, the axial anisotropy field is equal to the superposition of the demagnetization field and the equivalent field of magnetocrystalline anisotropy. This significantly increases the natural resonance frequency of the film. Simultaneously, the microwave permeability of the film is unaffected by magnetocrystalline anisotropy and remains high. These rare earth-transition metal soft magnetic materials, with their excellent intrinsic properties, transcend the limitations of traditional Fe- / Co-based and planar hexagonal ferrite materials, combining high permeability with high cutoff frequency, and are expected to become a new generation of high-frequency soft magnetic thin film materials. Summary of the Invention

[0004] The present invention aims to address the deficiencies in the prior art and provides a planar anisotropic rare earth-based high-frequency soft magnetic film and a preparation method thereof.

[0005] One object of the present invention is achieved by the following technical solutions:

[0006] A planar anisotropic rare earth-based high-frequency soft magnetic film, wherein the rare earth-based high-frequency soft magnetic film is composed of RE2TM 17 , where RE is a rare earth element and TM is a transition metal element.

[0007] Preferably, the rare earth element is one or more of lanthanides, Sc, and Y, wherein the lanthanides are La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.

[0008] Preferably, the transition metal element is one or more of Fe, Co, Ni, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, and Cu.

[0009] More preferably, the rare earth element is one or more of Y, Pr, Nd, Gd, Tb, Dy, Ho, and Lu.

[0010] More preferably, TM is one or both of Co and Fe.

[0011] Another object of the present invention is achieved through the following technical solutions:

[0012] A method for preparing a planar anisotropic rare earth-based high-frequency soft magnetic film comprises the following steps: depositing a rare earth-transition metal film on a substrate, and then preparing RE2TM by vacuum annealing. 17 Soft magnetic film.

[0013] Preferably, the substrate is Al2O3, oriented in the (0001) direction. 17 Thin film, because the hexagonal structure of Al2O3 is the same crystal structure as the final desired structure, the lattice is more matched and more conducive to the growth of RE2TM 17 texture.

[0014] Preferably, the rare earth-transition metal thin film is deposited on the substrate by magnetron sputtering.

[0015] Preferably, the target material for magnetron sputtering is an alloy target with an atomic ratio of rare earth elements to transition metal elements of 2:17.

[0016] Preferably, the magnetron sputtering process parameters are: argon gas pressure 0.1-1.0 Pa, sputtering power 50-200 W, and deposition time 60-120 min.

[0017] Further preferably, the magnetron sputtering process parameters are: argon gas pressure 0.5 Pa, sputtering power 80 W, and deposition time 90 min.

[0018] Preferably, the vacuum annealing process is performed at a vacuum degree of less than 1×10 -3 Paozhong carried out.

[0019] Preferably, the annealing temperature of the vacuum annealing treatment is 500-800° C., and the holding time is 1-40 hours.

[0020] Preferably, after the vacuum annealing treatment, rapid water cooling is performed, which prevents excessive grain growth and enables the formation of an ideal texture.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention provides a composition comprising RE2TM 17 Planar anisotropic rare earth-based high-frequency soft magnetic films;

[0023] 2. The present invention successfully prepared RE2TM by magnetron sputtering and vacuum annealing. 17 , rare earth-based soft magnetic films with planar anisotropy;

[0024] 3. The planar anisotropic rare earth-based high-frequency soft magnetic film of the present invention is deposited on an Al2O3 substrate oriented in the (0001) direction. Since the hexagonal structure of Al2O3 is the same crystal structure as the final desired structure, the lattice is more matched and more conducive to the growth of RE2TM 17 texture;

[0025] 4. The microwave magnetic properties of traditional Fe- / Co-based soft magnetic film materials follow the Acher limit. Increasing the frequency will inevitably sacrifice the magnetic permeability. The present invention breaks through the Acher limit of the soft magnetic film and the prepared composition is RE2TM 17 The planar anisotropic rare earth-based high-frequency soft magnetic film improves the natural resonance frequency without sacrificing magnetic permeability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Y2Co in Examples 1-5 17 XRD patterns corresponding to rare earth soft magnetic films;

[0027] Figure 2 a is the magnetic spectrum of the Y-Co thin film as prepared but not annealed in Example 3; Figure 2 b is Y2Co in Example 3 17 Magnetic spectrum results of rare earth soft magnetic films. DETAILED DESCRIPTION

[0028] Below by specific embodiment and accompanying drawing, technical scheme of the present invention is further described explanation, it should be understood that specific embodiment described herein is only for helping to understand the present invention, is not used for specific limitation of the present invention.And accompanying drawing used herein, is only for better illustrating the disclosure of the present invention, does not have limiting effect on protection scope.If no special instructions, the raw materials adopted in the embodiment of the present invention are all raw materials commonly used in this area, and the method adopted in the embodiment is all conventional method in this area.

[0029] Example 1

[0030] A planar anisotropic rare earth-based high-frequency soft magnetic film composed of Y2Co 17 , and its preparation method comprises the following steps:

[0031] A Y-Co thin film was grown on an Al2O3 substrate oriented in the (0001) direction using a magnetron sputtering deposition device. The magnetron sputtering target was an alloy target with an atomic ratio of Y to Co of 2:17. The magnetron sputtering process conditions were: argon pressure 0.5 Pa, sputtering power 80 W, and deposition time 90 min.

[0032] The Y-Co film was vacuum annealed at a vacuum degree of 1×10 -5 Pa, the annealing temperature of the vacuum annealing treatment is 500℃, the holding time is 1h, and after vacuum annealing treatment, rapid water cooling is obtained to obtain Y2Co 17 Rare earth-transition metal compound high-frequency soft magnetic films.

[0033] Example 2

[0034] The difference between Example 2 and Example 1 is that the annealing temperature of Example 2 is 550°C.

[0035] Example 3

[0036] The difference between Example 3 and Example 1 is that the annealing temperature of Example 3 is 600°C.

[0037] Example 4

[0038] The difference between Example 4 and Example 1 is that the annealing temperature of Example 4 is 650°C.

[0039] Example 5

[0040] The difference between Example 5 and Example 1 is that the annealing temperature of Example 5 is 700°C.

[0041] Example 6

[0042] A planar anisotropic rare earth-based high-frequency soft magnetic film composed of Y2Fe 17 , and its preparation method comprises the following steps:

[0043] A Y-Fe thin film was grown on an Al2O3 substrate oriented in the (0001) direction using a magnetron sputtering deposition device. The magnetron sputtering target was an alloy target with an atomic ratio of Y to Fe of 2:17. The magnetron sputtering process conditions were: argon pressure 0.5 Pa, sputtering power 80 W, and deposition time 90 min.

[0044] The Y-Fe film was vacuum annealed at a vacuum degree of 1×10 -5 Pa, the annealing temperature of the vacuum annealing treatment is 650 ° C, the holding time is 1h, and after vacuum annealing treatment, rapid water cooling is obtained to obtain Y2Fe 17 Rare earth-transition metal compound high-frequency soft magnetic films.

[0045] Example 7

[0046] A planar anisotropic rare earth-based high-frequency soft magnetic film, composed of Y2Fe9Co8, and a preparation method thereof comprising the following steps:

[0047] A Y-Fe-Co thin film was grown on an Al2O3 substrate oriented in the (0001) direction using a magnetron sputtering deposition device. The magnetron sputtering target was an alloy target with an atomic ratio of Y to FeCo of 2:9:8. The magnetron sputtering process conditions were: argon pressure 0.5 Pa, sputtering power 80 W, and deposition time 90 min.

[0048] The Y-Fe-Co film was vacuum annealed at a vacuum degree of 1×10 -5 The vacuum annealing treatment is carried out under Pa, the annealing temperature is 650℃, the holding time is 1h, and after the vacuum annealing treatment, it is quickly water-cooled to obtain the Y2Fe9Co8 rare earth-transition metal intermetallic compound high-frequency soft magnetic film.

[0049] Example 8

[0050] A planar anisotropic rare earth-based high-frequency soft magnetic film composed of Nd2Co 17 , and its preparation method comprises the following steps:

[0051] A Nd-Co thin film was grown on an Al2O3 substrate oriented in the (0001) direction using a magnetron sputtering deposition device. The magnetron sputtering target was an alloy target with an atomic ratio of Nd to Co of 2:17. The magnetron sputtering process conditions were: argon pressure 0.5 Pa, sputtering power 80 W, and deposition time 90 min.

[0052] The Nd-Co film was vacuum annealed at a vacuum degree of 1×10 -5 The annealing temperature of the vacuum annealing treatment was 650℃ and the holding time was 1h. After the vacuum annealing treatment, the Nd2Co 17 Rare earth-transition metal compound high-frequency soft magnetic films.

[0053] Comparative Example 1

[0054] The difference between Comparative Example 1 and Example 1 is that no annealing treatment was performed in Comparative Example 1. The Y-doped Co thin film obtained had a natural resonance frequency of only 2.87 GHz.

[0055] Comparative Example 2

[0056] The difference between Comparative Example 2 and Example 1 is that the annealing temperature in Comparative Example 1 is 900° C. Too high an annealing temperature causes Y in the film to escape, preventing the formation of rare earth-transition metal intermetallic compounds, and causing the film to crack at high temperatures.

[0057] Comparative Example 3

[0058] The difference between Comparative Example 3 and Example 1 is that the annealing temperature of Comparative Example 1 is 400°C.

[0059] Comparative Example 4

[0060] The difference between Comparative Example 4 and Example 1 is that after vacuum annealing, slow air cooling is performed in Comparative Example 4. Under slow air cooling, the grains grow and the texture is destroyed.

[0061] Performance Testing

[0062] Figure 1 Y2Co in Examples 1-5 17 The XRD spectrum of the soft magnetic film shows that the peak position of the spectrum is 44.2°, corresponding to Y2Co 17 (006) crystal plane of the phase.

[0063] The magnetic spectra of the soft magnetic films of Examples 1-5 were tested using a vector network analyzer and a short-circuited microstrip line fixture. Figure 2 a is the magnetic spectrum of the as-prepared unannealed Y-Co film. Figure 2 b is Y2Co in Example 3 17 Magnetic spectrum results of rare earth soft magnetic films. Compared with the unannealed Y-Co film, the Y2Co 17 It has planar anisotropy, and its natural resonance frequency is greatly improved, which is much larger than the Fe- / Co-based soft magnetic films that are currently widely studied.

[0064] The magnetic permeability (μ), natural resonance frequency (f r The results of ) and damping factor (α) are shown in Table 1.

[0065] Table 1 Magnetic permeability (μ), natural resonance frequency (f r ) and the damping factor (α)

[0066]

[0067]

[0068] The soft magnetic films of Examples 1-8 have excellent natural resonance frequencies. The natural resonance frequency of the unannealed film (Comparative Example 1) is only 2.87 GHz; the annealing temperature is too high (Comparative Example 2), which causes the rare earth elements in the film to escape and cannot form rare earth-transition metal compounds, and the film is prone to cracking at high temperatures; while the annealing temperature is too low (Comparative Example 3), the natural resonance frequency is lower and the damping factor is higher.

[0069] The various aspects, embodiments, and features of the present invention should be considered in all respects as illustrative and not limiting, the scope of which is defined solely by the claims. Other embodiments, modifications, and uses will be apparent to those skilled in the art without departing from the spirit and scope of the invention as claimed.

[0070] In the preparation method of the present invention, the order of the steps is not limited to the order listed. Persons skilled in the art will appreciate that variations in the order of the steps are within the scope of the present invention without inventive effort. Furthermore, two or more steps or actions may be performed simultaneously.

[0071] Finally, it should be noted that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit its implementation. Persons skilled in the art may make various modifications, additions, or substitute similar methods for the described specific embodiments. It is not necessary and impossible to provide comprehensive examples of all implementations here. However, obvious variations or modifications arising from the essential spirit of the present invention remain within the scope of protection of the present invention, and interpreting them as any additional limitations would be contrary to the spirit of the present invention.

Claims

1. A method for preparing a planar anisotropic rare earth-based high-frequency soft magnetic film, characterized in that: The rare earth-based high-frequency soft magnetic film is composed of RE2TM 17 , wherein RE is one or more of lanthanide elements, Sc, and Y, and TM is one or more of Fe, Co, Ni, Mn, and Cu; The preparation method comprises the following steps: depositing a rare earth-transition metal thin film on a substrate by magnetron sputtering, wherein the magnetron sputtering process parameters are: argon gas pressure 0.1-1.0 Pa, sputtering power 50-200 W, deposition time 60-120 min, and then performing vacuum annealing to prepare RE2TM 17 Soft magnetic film; The substrate is Al2O3, oriented in the (0001) direction; The annealing temperature of vacuum annealing treatment is 500~800℃, and the holding time is 1~40h; After vacuum annealing, rapid water cooling is performed.

2. The preparation method according to claim 1, characterized in that The target material for magnetron sputtering is an alloy target with an atomic ratio of rare earth elements to transition metal elements of 2:

17.

3. The preparation method according to claim 1, characterized in that Vacuum annealing treatment is performed at a vacuum degree of less than 1×10 -3 Paozhong carried out.

4. A planar anisotropic rare earth-based high-frequency soft magnetic film, characterized in that: The rare earth-based high-frequency soft magnetic film is composed of RE2TM 17 , wherein RE is one or more of lanthanide elements, Sc, and Y, and TM is one or more of Fe, Co, Ni, Mn, and Cu; The method for preparing the rare earth-based high-frequency soft magnetic film comprises the following steps: depositing a rare earth-transition metal film on a substrate by magnetron sputtering, wherein the magnetron sputtering process parameters are: argon gas pressure 0.1-1.0 Pa, sputtering power 50-200 W, deposition time 60-120 min, and then performing vacuum annealing to prepare RE2TM 17 Soft magnetic film; The substrate is Al2O3, oriented in the (0001) direction; The annealing temperature of vacuum annealing treatment is 500~800℃, and the holding time is 1~40h; After vacuum annealing, rapid water cooling is performed.

5. The planar anisotropic rare earth-based high-frequency soft magnetic film according to claim 4, characterized in that: The target material for magnetron sputtering is an alloy target with an atomic ratio of rare earth elements to transition metal elements of 2:17.

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