Magnetic code disc film material and preparation method and application thereof

Abstract

The invention provides a magnetic code disc film material and a preparation method and application thereof. By introducing the TiN layer, a proper amount of nitrogen atoms can enter lattice gaps of iron, electron cloud distribution of iron atoms is changed, and the magnetic moment of the iron atoms is changed; the magnetic moment of Fe atoms can be influenced by N atoms and crystal structures, an alpha-Fe8N phase is formed in FeCoCr through introduction of N ions, the average magnetic moment of each Fe atom in the alpha-Fe8N phase is 2.4 mu B, alpha-Fe8N is a metastable phase, a sample can finally form stable gamma '-Fe4N through annealing, and the magnetic moment of the stable gamma'-Fe4N is generally about 2.5 mu B-2. 7 mu B and is higher than the magnetic moment 2.2 mu B of the Fe atoms in metal Fe; besides, Ti forms a Ti-Fe weak magnetic phase pinning magnetic domain wall in the FeCoCr thin film, and the coercive force and residual magnetism of the FeCoCr layer can be effectively improved at the same time through the method.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic materials, and in particular to a magnetic code disk thin film material, a preparation method thereof, and an application thereof. Background Art

[0002] FeCoCr alloys were first discovered in 1972. Within a specific composition range, FeCoCr alloys can achieve ideal permanent magnetic properties after magnetic field heat treatment, combining high remanence and coercivity, even achieving a magnetic energy product comparable to that of AlNiCo alloys. Furthermore, FeCoCr alloys exhibit excellent processability and ductility, leading to a wide range of applications. Compared to three-dimensional bulk materials, two-dimensional thin film materials typically exhibit superior and unique magnetic properties. With the continued booming global information industry, electronic information devices are moving towards intelligence, integration, and miniaturization, and research on two-dimensional magnetic thin film materials has gradually attracted widespread attention. The accuracy of magnetic encoders is closely related to the performance and structure of the hard magnetic film used in magnetic code disks. To ensure easy writing of magnetic pole signals while ensuring strong resistance to external magnetic field interference, the coercivity of magnetic code disk film materials must be maintained within a certain range. To facilitate reading of magnetic pole signals and increase output signal strength, magnetic code disk film materials require high remanent magnetization. In recent years, to meet the diverse requirements of magnetic thin film materials for various applications, researchers have attempted to manipulate the magnetic properties of FeCoCr alloy thin films through various approaches. Previous studies on FeCoCr thin films have often targeted target composition design, sample preparation conditions, and annealing processes. Studies have found that FeCoCr thin films require shorter annealing times to achieve coercivity similar to that of bulk FeCoCr materials, likely due to faster atomic diffusion in thin films. In bulk materials, atoms can diffuse only through grain boundaries, whereas in thin films, atoms can diffuse not only through grain boundaries but also along the surface. While the coercivity of FeCoCr films can be influenced by modifying the substrate, introducing a seed layer, adjusting the elemental composition, and optimizing the annealing process and growth parameters, sufficient remanent magnetization cannot be achieved. Because it is often difficult to simultaneously achieve an ideal structure with a highly uniform distribution of both soft and hard magnetic phases in FeCoCr films, these manipulation methods often only manage either the coercivity or the remanence of the film, making it difficult to achieve a balanced balance between coercivity and remanence in FeCoCr films.

[0003] How to synergistically and significantly improve the coercivity and remanence of thin films through effective means, especially by finding new ideas and methods that are different from previous research, is a key issue that needs to be urgently addressed in the development of high-performance FeCoCr thin film materials. Summary of the Invention

[0004] In view of this, the present invention provides a magnetic code disk thin film material and a preparation method and application thereof, so as to solve or at least partially solve the defects in the prior art.

[0005] In a first aspect, the present invention provides a magnetic code disk thin film material, comprising:

[0006] substrate;

[0007] a buffer layer located on the surface of the substrate;

[0008] a first Ti layer, which is located on a surface of the buffer layer away from the substrate;

[0009] a first FeCoCr layer located on a surface of the first Ti layer away from the substrate;

[0010] a TiN layer located on a surface of the first FeCoCr layer away from the substrate;

[0011] a second FeCoCr layer located on a surface of the TiN layer away from the substrate;

[0012] A second Ti layer is located on a surface of the second FeCoCr layer away from the substrate.

[0013] Preferably, the first FeCoCr layer and the second FeCoCr layer include the following elements: Fe, Co, Cr, Mo, and Ti.

[0014] Preferably, the first FeCoCr layer and the second FeCoCr layer include the following elements in mass fractions: Fe 40-45%, Co 20-25%, Cr 30-35%, Mo 2-4%, and Ti 0.5-1%.

[0015] Preferably, the substrate includes any one of a Si substrate, a sapphire substrate, a MgO substrate, and a stainless steel substrate;

[0016] And / or, the material of the buffer layer includes any one of Cr, Ta, and Ru.

[0017] Preferably, the thickness of the substrate is 0.1 to 1 mm;

[0018] and / or, the thickness of the buffer layer is 20 to 30 nm;

[0019] and / or, the thickness of the first Ti layer is 5 to 10 nm;

[0020] and / or, the thickness of the first FeCoCr layer is 50 to 60 nm;

[0021] and / or, the thickness of the TiN layer is 1 to 10 nm;

[0022] and / or, the thickness of the second FeCoCr layer is 50 to 60 nm;

[0023] And / or, the thickness of the second Ti layer is 5-10 nm.

[0024] In a second aspect, the present invention further provides a method for preparing the magnetic code disk thin film material, comprising the following steps:

[0025] A buffer layer, a first Ti layer, a first FeCoCr layer, a TiN layer, a second FeCoCr layer, and a second Ti layer are sequentially deposited on the substrate;

[0026] Under a vacuum environment, the substrate formed with the multilayer film is annealed to obtain a magnetic code disk thin film material.

[0027] Preferably, in the step of annealing the substrate with the multilayer film formed thereon under a vacuum environment, the annealing temperature is 600-650° C., the annealing time is 30-40 min, and the vacuum degree of the vacuum environment is 1×10 -5 ~5×10 -5 Pa.

[0028] Preferably, the TiN layer is prepared by: using TiN as a target material, a direct current sputtering method is used to prepare a TiN layer on the first FeCoCr layer; or using Ti as a target material and introducing N2, a direct current sputtering method is used to prepare a TiN layer on the first FeCoCr layer; wherein, during sputtering, the background vacuum degree of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa, the working pressure of argon is 3~6mTorr.

[0029] Preferably, the buffer layer, the first Ti layer, the first FeCoCr layer, the second FeCoCr layer, and the second Ti layer are prepared by DC sputtering; wherein, during sputtering, the background vacuum degree of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa, the working pressure of argon is 3~6mTorr.

[0030] In a third aspect, the present invention further provides an application of the magnetic code disk thin film material or the magnetic code disk thin film material prepared by the preparation method in preparing a magnetic encoder.

[0031] The magnetic code disk film material and its preparation method and application of the present invention have the following advantages over the prior art:

[0032] Beneficial effects:

[0033] 1. The magnetic code disk thin film material of the present invention, by introducing a TiN layer, an appropriate amount of nitrogen atoms can enter the iron lattice gap, change the electron cloud distribution of the iron atoms, and change the magnetic moment of the iron atoms; the magnetic moment of the Fe atoms is affected by the N atoms and the crystal structure. The introduction of N ions forms an α-Fe8N phase in FeCoCr. The average magnetic moment of each Fe atom in the α-Fe8N phase is 2.4μ B α-Fe8N is a metastable phase. After annealing, the sample can eventually form a stable γ'-Fe4N, whose magnetic moment is usually about 2.5μ B ~2.7μ B About (higher than the magnetic moment of Fe atoms in metal Fe 2.2μ B ); In addition, Ti forms a Ti-Fe weak magnetic phase pinning magnetic domain wall in the FeCoCr film. By this method, the coercivity and remanence of the FeCoCr layer can be effectively improved at the same time; the magnetic code disk film material of the present invention can be used as a code disk material for encoders, and is used in high-end intelligent equipment such as CNC machine tools and robots, and has the advantages of high precision, high speed resistance, high impact resistance and vibration resistance;

[0034] 2. The preparation method of the magnetic code disk thin film material of the present invention, after annealing, N and Ti in the TiN layer will diffuse to the upper and lower FeCoCr layers (i.e., the second FeCoCr layer and the first FeCoCr layer), and the supersaturated solid solution of N in the α-Fe phase has lattice constants of First, α-Fe8N is formed in the film, and after the annealing process, a stable γ'-Fe4N is formed in the film. The magnetic moment of γ'-Fe4N is usually about 2.5μ B -2.7μ B About (higher than the magnetic moment of Fe atoms in metal Fe 2.2μ B ), therefore, the remanence of the film is improved compared to the film without the introduction of the TiN layer. In addition, since Ti forms a Ti-Fe weak magnetic phase with part of Fe during the diffusion process, it will pin the magnetic domain wall so that the remanence of the film is improved while the coercive force is also improved. Through this method, the coercive force and remanence of the film can be effectively and synergistically improved. More importantly, from the perspective of practical applications, the development of high-precision magnetic encoders requires that the code disk material must ensure a uniform output signal while achieving high-density and small magnetic pole pitch. Therefore, the film material needs to meet the magnetic properties while taking into account the uniformity (homogeneity) of the material structure. By introducing the TiN layer, an appropriate amount of nitrogen atoms can enter the lattice gap of iron, change the electron cloud distribution of the iron atoms, and change the magnetic moment of the iron atoms. The γ'-Fe4N generated in the FeCoCr layer has a face-centered cubic structure (FCC) with a lattice constant of and The phases have similar lattice constants, which is different from the previous methods of regulating the magnetic properties of materials by creating defects and forming intermetallic compounds (such as: ), the formation of an appropriate amount of γ'-Fe4N not only promotes the improvement of the magnetic properties of the FeCoCr layer, but also takes into account the uniformity of the material, which has important guiding significance for the design and preparation of magnetic code disks for high-precision magnetic encoders. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0036] Figure 1 This is a schematic structural diagram of a thin film material for a magnetic code disk in one embodiment of the present invention;

[0037] Figure 2 is the hysteresis loop of the magnetic code disk thin film material prepared in Example 1;

[0038] Figure 3 This is the hysteresis loop of the magnetic code disk thin film material prepared in Comparative Example 1. DETAILED DESCRIPTION

[0039] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0041] In the description of the present invention, it should be understood that the directions or positions indicated by “upper” and the like are based on the directions or positions shown in the accompanying drawings, or are the directions or positions in which the product of the invention is usually placed when in use, or are the directions or positions commonly understood by those skilled in the art. These directions or positions are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or component referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0042] The following are detailed descriptions respectively. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments. In addition, in the description of this application, the term "including" means "including but not limited to". Various embodiments of the present invention may be in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be understood as a rigid limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the numbered ranges, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated in this article, it is meant to include any cited numbers (fractions or integers) within the indicated range.

[0043] The present invention provides a magnetic code disk film material, such as Figure 1 Shown, including:

[0044] Substrate 1;

[0045] a buffer layer 2, which is located on the surface of the substrate 1;

[0046] a first Ti layer 3, which is located on the surface of the buffer layer 2 away from the substrate 1;

[0047] a first FeCoCr layer 4, which is located on the surface of the first Ti layer away from the substrate 1;

[0048] A TiN layer 5 located on a surface of the first FeCoCr layer 4 away from the substrate 1;

[0049] a second FeCoCr layer 6 located on a surface of the TiN layer 5 away from the substrate 1;

[0050] The second Ti layer 7 is located on the surface of the second FeCoCr layer 6 away from the substrate 1 .

[0051] The magnetic code disk thin film material of the present invention includes a substrate 1 and a buffer layer 2, a first Ti layer 3, a first FeCoCr layer 4, a TiN layer 5, a second FeCoCr layer 6, and a second Ti layer 7 located on the surface of the substrate 1 and stacked in sequence. The magnetic code disk thin film material of the present invention introduces a TiN layer through an innovative structural design, so that an appropriate amount of nitrogen atoms can enter the lattice gap of iron, change the electron cloud distribution of the iron atoms, and change the magnetic moment of the iron atoms. The magnetic moment of Fe atoms is affected by N atoms and the crystal structure. The introduction of N ions forms an α-Fe8N phase in FeCoCr. The average magnetic moment of each Fe atom in the α-Fe8N phase is 2.4μ Bα-Fe8N is a metastable phase. After annealing, the sample can eventually form a stable γ'-Fe4N, whose magnetic moment is usually about 2.5μ B ~2.7μ B About (higher than the magnetic moment of Fe atoms in metal Fe 2.2μ B ); in addition, Ti forms a Ti-Fe weakly magnetic phase in the FeCoCr film, pinning magnetic domain walls. This method effectively and simultaneously enhances the coercivity and remanence of the FeCoCr layer. The magnetic code disk film material of this invention can be used in encoder code disks for high-end intelligent equipment such as CNC machine tools and robots, offering advantages such as high precision, high speed resistance, and strong shock and vibration resistance.

[0052] In some embodiments, the first FeCoCr layer 4 and the second FeCoCr layer 6 include the following elements: Fe, Co, Cr, Mo, and Ti.

[0053] In some embodiments, the first FeCoCr layer 4 and the second FeCoCr layer 6 include the following elements in mass fractions: Fe 40-45%, Co 20-25%, Cr 30-35%, Mo 2-4%, and Ti 0.5-1%.

[0054] Further preferably, the first FeCoCr layer 4 and the second FeCoCr layer 6 include the following elements in mass fractions: Fe 42%, Co 25%, Cr 30%, Mo 3%, and Ti 1%.

[0055] In some embodiments, substrate 1 comprises any one of a Si substrate, a sapphire substrate, an MgO substrate, and a stainless steel substrate. Preferably, substrate 1 comprises a single-polished MgO substrate with a (001) orientation. The lattice of this substrate is well matched to the buffer Cr layer, facilitating the deposition and growth of the thin film.

[0056] In some embodiments, the material of the buffer layer 2 includes any one of Cr, Ta, and Ru. Preferably, the material of the buffer layer 2 is Cr.

[0057] In some embodiments, the thickness of the substrate 1 is 0.1-1 mm.

[0058] In some embodiments, the buffer layer 2 has a thickness of 20-30 nm, preferably 20 nm.

[0059] In some embodiments, the thickness of the first Ti layer 3 is 5-10 nm, preferably, 5 nm.

[0060] In some embodiments, the thickness of the first FeCoCr layer 4 is 50-60 nm, preferably 50 nm.

[0061] In some embodiments, the thickness of the TiN layer 5 is 1-10 nm, preferably, 10 nm.

[0062] In some embodiments, the second FeCoCr layer 6 has a thickness of 50-60 nm, preferably 50 nm.

[0063] In some embodiments, the thickness of the second Ti layer 7 is 5-10 nm, preferably 5 nm.

[0064] Based on the same inventive concept, the present invention also provides a method for preparing the above-mentioned magnetic code disk thin film material, comprising the following steps:

[0065] A buffer layer, a first Ti layer, a first FeCoCr layer, a TiN layer, a second FeCoCr layer, and a second Ti layer are sequentially deposited on the substrate;

[0066] Under a vacuum environment, the substrate formed with the multilayer film is annealed to obtain a magnetic code disk thin film material.

[0067] In some embodiments, in the step of annealing the substrate formed with the multilayer film under a vacuum environment, the annealing temperature is 600-650° C., the annealing time is 30-40 min, and the vacuum degree of the vacuum environment is 1×10 -5 ~5×10 -5 Pa, preferably, the annealing temperature is 650° C. and the annealing time is 30 min.

[0068] In some embodiments, the TiN layer represents a Ti layer doped with N atoms, having a thickness of 1 to 10 nm, and can be obtained by sputtering a TiN target, or by reactive sputtering by introducing N2 gas when sputtering a Ti target; specifically, the TiN layer is prepared on the first FeCoCr layer by using TiN as a target material and a DC sputtering method; or, the TiN layer is prepared on the first FeCoCr layer by using Ti as a target material and introducing N2 gas, and the TiN layer is prepared on the first FeCoCr layer by using a DC sputtering method; wherein, during sputtering, the background vacuum of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa, the working pressure of argon is 3~6mTorr, the sputtering temperature is room temperature 20~25℃, and the sputtering power is 45~55W.

[0069] In some embodiments, a buffer layer, a first Ti layer, a first FeCoCr layer, a second FeCoCr layer, and a second Ti layer are prepared by DC sputtering; wherein, during sputtering, the background vacuum of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa, the working pressure of argon is 3~6mTorr.

[0070] In some embodiments, the buffer layer is made of Cr, and Cr is used as a target material. The buffer layer is deposited on the substrate by DC sputtering. During sputtering, the background vacuum of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa, the working pressure of argon is 3~6mTorr, the sputtering temperature is room temperature 20~25℃, and the sputtering power is 45~55W.

[0071] In some embodiments, a first Ti layer is deposited on the buffer layer using a DC sputtering method with Ti as the target. During sputtering, the background vacuum of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa, the working pressure of argon is 3~6mTorr, the sputtering temperature is room temperature 20~25℃, and the sputtering power is 45~55W.

[0072] In some embodiments, a first FeCoCr layer is deposited on the first Ti layer using a FeCoCrMoTi alloy as a target by DC sputtering. During sputtering, the background vacuum of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa, the working pressure of argon is 3~6mTorr, the sputtering temperature is room temperature 20~25℃, and the sputtering power is 25~35W.

[0073] In some embodiments, a second FeCoCr layer is deposited on the TiN layer using a DC sputtering method using a FeCoCrMoTi alloy as a target. During sputtering, the background vacuum of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa, the working pressure of argon is 3~6mTorr, the sputtering temperature is room temperature 20~25℃, and the sputtering power is 25~35W.

[0074] In some embodiments, a second Ti layer is deposited on the second FeCoCr layer using a DC sputtering method with Ti as the target. During sputtering, the background vacuum of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa, the working pressure of argon is 3~6mTorr, the sputtering temperature is room temperature 20~25℃, and the sputtering power is 45~55W.

[0075] In some embodiments, before depositing each layer on the substrate, the substrate is further cleaned. Specifically, the substrate is ultrasonically cleaned in aqueous ethanol, acetone, or anhydrous ethanol, and then blown dry with high-purity nitrogen.

[0076] The preparation method of the magnetic code disk thin film material of the present invention, after annealing, N and Ti in the TiN layer will diffuse to the upper and lower FeCoCr layers (i.e., the second FeCoCr layer and the first FeCoCr layer), and the supersaturated solid solution of N in the α-Fe phase has lattice constants of First, α-Fe8N is formed in the film, and after the annealing process, a stable γ'-Fe4N is formed in the film. The magnetic moment of γ'-Fe4N is usually about 2.5μ B -2.7μ B About (higher than the magnetic moment of Fe atoms in metal Fe 2.2μ B ), therefore, the remanence of the film is improved compared to the film without the introduction of the TiN layer. In addition, since Ti forms a Ti-Fe weak magnetic phase with part of Fe during the diffusion process, it will pin the magnetic domain wall so that the remanence of the film is improved while the coercive force is also improved. Through this method, the coercive force and remanence of the film can be effectively and synergistically improved. More importantly, from the perspective of practical applications, the development of high-precision magnetic encoders requires that the code disk material must ensure a uniform output signal while achieving high-density and small magnetic pole pitch. Therefore, the film material needs to meet the magnetic properties while taking into account the uniformity (homogeneity) of the material structure. By introducing the TiN layer, an appropriate amount of nitrogen atoms can enter the lattice gap of iron, change the electron cloud distribution of the iron atoms, and change the magnetic moment of the iron atoms. The γ'-Fe4N generated in the FeCoCr layer has a face-centered cubic structure (FCC) with a lattice constant of and The phases have similar lattice constants, which is different from the previous methods of regulating the magnetic properties of materials by creating defects and forming intermetallic compounds (such as: ), the formation of an appropriate amount of γ'-Fe4N not only promotes the improvement of the magnetic properties of the FeCoCr layer, but also takes into account the uniformity of the material, which has important guiding significance for the design and preparation of magnetic code disks for high-precision magnetic encoders.

[0077] Based on the same inventive concept, the present invention also provides the use of the aforementioned magnetic code disk film material, or the magnetic code disk film material prepared by the aforementioned preparation method, in the manufacture of a magnetic encoder. The magnetic code disk film material of the present invention can be used as a code disk material for encoders, particularly in high-end intelligent equipment such as CNC machine tools and robots, and exhibits advantages such as high precision, high speed resistance, and strong resistance to shock and vibration.

[0078] The following further illustrates the magnetic code disk thin film material and its preparation method of the present application with specific examples. This section further illustrates the content of the present invention in conjunction with specific examples, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the art.

[0079] Example 1

[0080] This embodiment provides a magnetic code disk thin film material, including:

[0081] substrate;

[0082] a buffer layer located on the surface of the substrate;

[0083] a first Ti layer, which is located on a surface of the buffer layer away from the substrate;

[0084] a first FeCoCr layer located on a surface of the first Ti layer away from the substrate;

[0085] A TiN layer is located on a surface of the first FeCoCr layer away from the substrate;

[0086] a second FeCoCr layer located on a surface of the TiN layer away from the substrate;

[0087] a second Ti layer located on a surface of the second FeCoCr layer away from the substrate;

[0088] The first FeCoCr layer and the second FeCoCr layer include the following elements in mass fractions: Fe 42%, Co 25%, Cr 30%, Mo 3%, and Ti 1%;

[0089] The substrate is a MgO substrate with a (001) orientation and a thickness of 0.5 mm;

[0090] The material of the buffer layer is Cr, and the thickness of the buffer layer is 20 nm;

[0091] The thickness of the first Ti layer is 5 nm;

[0092] The thickness of the first FeCoCr layer is 50 nm;

[0093] The thickness of the TiN layer is 10 nm;

[0094] The thickness of the second FeCoCr layer is 50 nm;

[0095] The thickness of the second Ti layer is 5 nm.

[0096] The method for preparing the magnetic code disk thin film material comprises the following steps:

[0097] S1. Using a Cr target, a Ti target, a FeCoCrMoTi alloy target, a TiN target, a FeCoCrMoTi alloy target, and a Ti target, a buffer layer, a first Ti layer, a first FeCoCr layer, a TiN layer, a second FeCoCr layer, and a second Ti layer are sequentially deposited on a substrate by a DC sputtering method to form a substrate / Cr / Ti / FeCoCr / TiN / FeCoCr / Ti multilayer film; the FeCoCrMoTi alloy target includes the following elements by mass fraction: Fe 42%, Co 25%, Cr 30%, Mo 3%, and Ti 1%;

[0098] S2. Annealing the substrate / Cr / Ti / FeCoCr / TiN / FeCoCr / Ti multilayer film in a vacuum environment to obtain a magnetic code disk thin film material;

[0099] The buffer layer was deposited on the substrate by DC sputtering. During sputtering, the background vacuum of the sputtering chamber was 3×10 -5 Pa, the working pressure of argon was 3 mTorr, the sputtering temperature was room temperature 25 °C, and the sputtering power was 50 W;

[0100] The first Ti layer was deposited on the buffer layer by DC sputtering. During sputtering, the background vacuum of the sputtering chamber was 3×10 -5 Pa, the working pressure of argon was 3 mTorr, the sputtering temperature was room temperature 25 °C, and the sputtering power was 45 W;

[0101] The first FeCoCr layer was deposited on the first Ti layer by DC sputtering with FeCoCrMoTi alloy as the target. During sputtering, the background vacuum of the sputtering chamber was 3×10 -5 Pa, the working pressure of argon was 3 mTorr, the sputtering temperature was room temperature 25 °C, and the sputtering power was 30 W;

[0102] The TiN layer was prepared on the first FeCoCr layer by DC sputtering with TiN as the target. During sputtering, the background vacuum of the sputtering chamber was 3×10 -5 Pa, the working pressure of argon was 3 mTorr, the sputtering temperature was room temperature 25 °C, and the sputtering power was 50 W;

[0103] The second FeCoCr layer was deposited on the TiN layer by DC sputtering with FeCoCrMoTi alloy as the target. During sputtering, the background vacuum of the sputtering chamber was 3×10 -5 Pa, the working pressure of argon was 3 mTorr, the sputtering temperature was room temperature 25 °C, and the sputtering power was 30 W;

[0104] The second Ti layer was deposited on the second FeCoCr layer by DC sputtering with Ti as the target. During sputtering, the background vacuum of the sputtering chamber was 3×10 -5 Pa, the working pressure of argon was 3 mTorr, the sputtering temperature was room temperature 25 °C, and the sputtering power was 45 W;

[0105] In the step of annealing the substrate with the multilayer film formed thereon under a vacuum environment in S2, the annealing temperature is 650° C., the annealing time is 30 min, and the vacuum degree of the vacuum environment is 1×10 -5 Pa.

[0106] Comparative Example 1

[0107] The magnetic code disk thin film material provided in this comparative example is the same as that in Example 1, but does not contain a TiN layer. Specifically, the magnetic code disk thin film material in Comparative Example 1 includes:

[0108] substrate;

[0109] a buffer layer located on the surface of the substrate;

[0110] a first Ti layer, which is located on a surface of the buffer layer away from the substrate;

[0111] a first FeCoCr layer located on a surface of the first Ti layer away from the substrate;

[0112] a second FeCoCr layer located on a surface of the first FeCoCr layer away from the substrate;

[0113] a second Ti layer located on a surface of the second FeCoCr layer away from the substrate;

[0114] The first FeCoCr layer and the second FeCoCr layer include the following elements in mass fractions: Fe 42%, Co 25%, Cr 30%, Mo 3%, and Ti 1%;

[0115] The substrate is a MgO substrate with a (001) orientation and a thickness of 0.5 mm;

[0116] The material of the buffer layer is Cr, and the thickness of the buffer layer is 20 nm;

[0117] The thickness of the first Ti layer is 5 nm;

[0118] The thickness of the first FeCoCr layer is 50 nm;

[0119] The thickness of the second FeCoCr layer is 50 nm;

[0120] The thickness of the second Ti layer is 5 nm.

[0121] The method for preparing the magnetic code disk thin film material comprises the following steps:

[0122] S1. Using a Cr target, a Ti target, a FeCoCrMoTi alloy target, a FeCoCrMoTi alloy target, and a Ti target, a buffer layer, a first Ti layer, a first FeCoCr layer, a second FeCoCr layer, and a second Ti layer are sequentially deposited on a substrate by a DC sputtering method to form a substrate / Cr / Ti / FeCoCr / FeCoCr / Ti multilayer film; the FeCoCrMoTi alloy target comprises the following elements by mass: Fe 42%, Co 25%, Cr 30%, Mo 3%, and Ti 1%;

[0123] S2. Annealing the substrate / Cr / Ti / FeCoCr / FeCoCr / Ti multilayer film in a vacuum environment to obtain a magnetic code disk thin film material;

[0124] The buffer layer was deposited on the substrate by DC sputtering. During sputtering, the background vacuum of the sputtering chamber was 3×10 -5 Pa, the working pressure of argon was 3 mTorr, the sputtering temperature was room temperature 25 °C, and the sputtering power was 50 W;

[0125] The first Ti layer was deposited on the buffer layer by DC sputtering. During sputtering, the background vacuum of the sputtering chamber was 3×10 -5 Pa, the working pressure of argon was 3 mTorr, the sputtering temperature was room temperature 25 °C, and the sputtering power was 45 W;

[0126] The first FeCoCr layer was deposited on the first Ti layer by DC sputtering with FeCoCrMoTi alloy as the target. During sputtering, the background vacuum of the sputtering chamber was 3×10 -5 Pa, the working pressure of argon was 3 mTorr, the sputtering temperature was room temperature 25 °C, and the sputtering power was 30 W;

[0127] The second FeCoCr layer was deposited on the first FeCoCr layer by DC sputtering with FeCoCrMoTi alloy as the target. During sputtering, the background vacuum of the sputtering chamber was 3×10 -5 Pa, the working pressure of argon was 3 mTorr, the sputtering temperature was room temperature 25 °C, and the sputtering power was 30 W;

[0128] The second Ti layer was deposited on the second FeCoCr layer by DC sputtering with Ti as the target. During sputtering, the background vacuum of the sputtering chamber was 3×10 -5 Pa, the working pressure of argon was 3 mTorr, the sputtering temperature was room temperature 25 °C, and the sputtering power was 45 W;

[0129] In the step of annealing the substrate with the multilayer film formed thereon under a vacuum environment in S2, the annealing temperature is 650° C., the annealing time is 30 min, and the vacuum degree of the vacuum environment is 1×10 -5 Pa.

[0130] Comparative Example 2

[0131] This comparative example provides a FeCoCr single-layer film, comprising:

[0132] substrate;

[0133] A FeCoCr layer located on the substrate surface;

[0134] The FeCoCr layer includes the following elements in mass fractions: Fe 42%, Co 25%, Cr 30%, Mo 3%, Ti 1%;

[0135] The substrate is a MgO substrate with a (001) orientation and a thickness of 0.5 mm;

[0136] The thickness of the FeCoCr layer is 50 nm.

[0137] The method for preparing the FeCoCr single-layer film comprises the following steps:

[0138] S1. Using a FeCoCrMoTi alloy target, a FeCoCr layer is deposited on a substrate by a DC sputtering method to obtain a substrate / FeCoCr film; the FeCoCrMoTi alloy target comprises the following elements by mass: Fe 42%, Co 25%, Cr 30%, Mo 3%, and Ti 1%;

[0139] S2. Annealing the substrate / FeCoCr film in a vacuum environment to obtain a magnetic code disk thin film material;

[0140] The FeCoCrMoTi alloy was used as the target material and the FeCoCr layer was deposited on the substrate by DC sputtering. During sputtering, the background vacuum of the sputtering chamber was 3×10 -5 Pa, the working pressure of argon was 3 mTorr, the sputtering temperature was room temperature 25 °C, and the sputtering power was 30 W;

[0141] In the step of annealing the substrate with the multilayer film formed thereon under a vacuum environment in S2, the annealing temperature is 650° C., the annealing time is 30 min, and the vacuum degree of the vacuum environment is 1×10 -5 Pa.

[0142] Performance Testing

[0143] The hysteresis loop of the magnetic code disk film material prepared in Example 1 was measured at room temperature using a Versalab vibrating sample magnetometer (VSM). Figure 2 shown.

[0144] The hysteresis loop of the magnetic code disk film material prepared in Comparative Example 1 was measured at room temperature using a Versalab vibrating sample magnetometer (VSM). Figure 3 shown.

[0145] from Figure 2 It can be seen from the figure that the coercive force of the magnetic code disk film material prepared in Example 1 is better than 570Oe, and the residual magnetization is better than 5000Oe; Figure 3 As can be seen, the coercivity and remanence of the magnetic code disk thin film material prepared in Comparative Example 1 are approximately 490 Oe and 2300 Oe, respectively; the coercivity and remanence of the FeCoCr single-layer film prepared in Comparative Example 2 are approximately 470 Oe and 4100 Oe, respectively. Compared with Comparative Examples 1 and 2, the magnetic code disk thin film material prepared in Example 1 has both higher coercivity and remanence. This method can effectively synergistically improve the coercivity and remanence of the film.

[0146] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A magnetic code disk thin film material, characterized in that: include: substrate; a buffer layer located on the surface of the substrate; a first Ti layer, which is located on a surface of the buffer layer away from the substrate; a first FeCoCr layer located on a surface of the first Ti layer away from the substrate; a TiN layer located on a surface of the first FeCoCr layer away from the substrate; a second FeCoCr layer located on a surface of the TiN layer away from the substrate; A second Ti layer is located on a surface of the second FeCoCr layer away from the substrate.

2. The magnetic code disk thin film material according to claim 1, wherein: The first FeCoCr layer and the second FeCoCr layer include the following elements: Fe, Co, Cr, Mo, and Ti.

3. The magnetic code disk thin film material according to claim 1, wherein: The first FeCoCr layer and the second FeCoCr layer include the following elements in mass fractions: Fe 40-45%, Co 20-25%, Cr 30-35%, Mo 2-4%, and Ti 0.5-1%.

4. The magnetic code disk thin film material according to claim 1, wherein: The substrate includes any one of a Si substrate, a sapphire substrate, a MgO substrate, and a stainless steel substrate; And / or, the material of the buffer layer includes any one of Cr, Ta, and Ru.

5. The magnetic code disk thin film material according to claim 1, wherein: The thickness of the substrate is 0.1 to 1 mm; and / or, the thickness of the buffer layer is 20 to 30 nm; and / or, the thickness of the first Ti layer is 5 to 10 nm; and / or, the thickness of the first FeCoCr layer is 50 to 60 nm; and / or, the thickness of the TiN layer is 1 to 10 nm; and / or, the thickness of the second FeCoCr layer is 50 to 60 nm; And / or, the thickness of the second Ti layer is 5-10 nm.

6. A method for preparing a magnetic code disk thin film material according to any one of claims 1 to 5, characterized in that: The following steps are involved: A buffer layer, a first Ti layer, a first FeCoCr layer, a TiN layer, a second FeCoCr layer, and a second Ti layer are sequentially deposited on the substrate; Under a vacuum environment, the substrate formed with the multilayer film is annealed to obtain a magnetic code disk thin film material.

7. The method for preparing a magnetic code disk thin film material according to claim 6, wherein: In the step of annealing the substrate with the multilayer film formed thereon under a vacuum environment, the annealing temperature is 600-650° C., the annealing time is 30-40 min, and the vacuum degree of the vacuum environment is 1×10 -5 ~5×10 -5 Pa.

8. The method for preparing a magnetic code disk thin film material according to claim 6, wherein: The TiN layer is prepared by using TiN as a target material and adopting a DC sputtering method to prepare a TiN layer on a first FeCoCr layer; or using Ti as a target material and introducing N2 to prepare a TiN layer on a first FeCoCr layer by a DC sputtering method; wherein, during sputtering, the background vacuum degree of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa, the working pressure of argon is 3~6mTorr.

9. The method for preparing a magnetic code disk thin film material according to claim 6, wherein: The buffer layer, the first Ti layer, the first FeCoCr layer, the second FeCoCr layer, and the second Ti layer were prepared by DC sputtering. During the sputtering, the background vacuum of the sputtering chamber was 1×10 -5 ~3×10 -5 Pa, the working pressure of argon is 3~6mTorr.

10. Use of the magnetic code disk thin film material according to any one of claims 1 to 5 or the magnetic code disk thin film material prepared by the preparation method according to any one of claims 6 to 9 in preparing a magnetic encoder.

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