Fe-pt alloy target and method of preparing the same

Abstract

This invention provides an iron-platinum alloy target and its manufacturing method. The iron-platinum alloy target comprises iron, platinum, carbon, boron nitride, and additive metals including tin, zinc, or combinations thereof. Based on the total number of atoms in the iron-platinum alloy target, the iron content is 26 at% to 42 at%, the platinum content is 25 at% to 38 at%, the carbon content is 1 at% to 30 at%, the boron nitride content is 10 at% to 35 at%, and the additive metal content is 0.5 at% to 6 at%. In its X-ray diffraction pattern, the ratio of the diffraction intensity value A at 2θ of 41.0° to 41.1° to the diffraction intensity value B at 2θ of 47.1° to 47.2° is 0.13 to 0.33. Thin films prepared by sputtering using this iron-platinum alloy target exhibit good magnetic properties.

Description

Technical Field

[0001] This invention relates to a ferro-platinum alloy target and its manufacturing method, particularly to a ferro-platinum alloy target for use in magnetic recording media and its manufacturing method. Prior Technology

[0002] With the increasing demand for information storage capacity in the market, perpendicular magnetic recording (PMR) media, which has a higher magnetic recording density, has been widely adopted in recent years to increase the storage capacity of hard drives. Furthermore, to further improve magnetic recording density, heat-assisted magnetic recording (HAMR) technology has been developed to achieve the goal of increasing storage capacity.

[0003] Generally speaking, the layered structure of heat-assisted magnetic recording media, from bottom to top, basically includes a substrate, adhesion layer, soft under layer, heat sink, under layer, diffusion barrier, magnetic recording layer, and cap layer. Among them, the magnetic recording layer achieves data writing by temporarily reducing the coercivity (usually referred to as Hc) of the magnetic particles by raising their temperature above the Curie temperature.

[0004] Regarding the selection of materials for the magnetic recording layer, iron-platinum alloys possess a unique L10 ordered structure and high magnetic anisotropy energy density, resulting in excellent magnetic recording performance, good magnetic recording stability, and support for high-density data writing. Therefore, currently, thin films are primarily formed using sputtered iron-platinum alloy targets as the magnetic recording layer. However, existing technologies for sputtering thin films with iron-platinum alloy targets still struggle to simultaneously improve magnetic properties such as coercivity, magnetic saturation (Ms), and magnetic anisotropy (Ku), thus failing to meet the demands for higher recording densities in heat-assisted magnetic recording media. Therefore, it is essential to develop technologies that can further enhance the magnetic properties of the magnetic recording layer to meet future industry developments and trends. Summary of the Invention

[0005] In view of the problems faced by the prior art, the purpose of the present invention is to provide an iron-platinum alloy target material, the thin film made by sputtering with it can simultaneously improve the three magnetic properties of coercivity, saturation magnetization and magnetocrystalline anisotropy, so as to be suitable for magnetic recording layers of heat-assisted magnetic recording media with higher recording density.

[0006] To achieve the aforementioned objectives, the present invention provides an iron-platinum alloy target material comprising iron (Fe), platinum (Pt), carbon (C), boron nitride (BN), and an additive metal comprising tin (Sn), zinc (Zn), or a combination thereof; wherein, based on the total atomic number of the iron-platinum alloy target material, the iron content is greater than or equal to 26 atomic percent (at%) and less than or equal to 42 at%, the platinum content is greater than or equal to 25 at% and less than or equal to 38 at%, the carbon content is greater than or equal to 1 at% and less than or equal to 30 at%, the boron nitride content is greater than or equal to 10 at% and less than or equal to 35 at%, and the additive metal content is greater than or equal to 0.5 at% and less than or equal to 6 at%. at%; In the X-ray diffraction pattern of the iron-platinum alloy target, there is a corresponding diffraction intensity value A at 2θ of 41.0° to 41.1°, and a corresponding diffraction intensity value B at 2θ of 47.1° to 47.2°, and the ratio of the diffraction intensity value B to the diffraction intensity value A is greater than or equal to 0.13 and less than or equal to 0.33.

[0007] By controlling the ratio of the iron-platinum alloy target of the present invention to a specific type and content range of constituent components (especially the specific type and content range of the added metal) and a specific 2θ range of diffraction intensity values ​​within a specific range, the thin film sputtered with the iron-platinum alloy target of the present invention simultaneously possesses good magnetic properties such as good coercivity (e.g., greater than or equal to 33 kilo-Oersted (kOe)), saturation magnetization (e.g., greater than or equal to 608 electromagnetic units / cubic centimeter (emu / cm3)), and magnetocrystalline anisotropy (e.g., greater than or equal to 1.93 × 107 erg / cubic centimeter (erg / cm3)).

[0008] According to the present invention, the "electromagnetic unit (emu)" is an abbreviation for "electromagnetic unit", which is a physical quantity commonly used to express magnetization in the CGS unit system, and can be converted to express it in the SI unit system, that is, "1 emu / cm3" equals "1000 amperes / meter (A / m)".

[0009] In some embodiments of the present invention, the diffraction intensity value A may be the diffraction intensity value corresponding to 2θ being 41.04° to 41.05° in the X-ray diffraction pattern of the iron-platinum alloy target. More specifically, the diffraction intensity value A may be the diffraction intensity value corresponding to 2θ being approximately 41.049° in the X-ray diffraction pattern of the iron-platinum alloy target.

[0010] In some embodiments of the present invention, the diffraction intensity value B may be the diffraction intensity value corresponding to 2θ being 47.12° to 47.13° in the X-ray diffraction pattern of the iron-platinum alloy target. More specifically, the diffraction intensity value B may be the diffraction intensity value corresponding to 2θ being approximately 47.123° in the X-ray diffraction pattern of the iron-platinum alloy target.

[0011] According to the present invention, the boron nitride may be hexagonal boron nitride (h-BN), cubic boron nitride (c-BN), close-packed hexagonal boron nitride (w-BN), or a combination thereof, but is not limited thereto.

[0012] In some embodiments of the present invention, the iron-platinum alloy target may further contain silver (Ag), and the silver content is greater than 0 at% and less than or equal to 10 at% based on the total number of atoms in the iron-platinum alloy target. In other embodiments of the present invention, the silver content is greater than or equal to 3 at% and less than or equal to 10 at% based on the total number of atoms in the iron-platinum alloy target. By further incorporating silver within a specific range into the composition of the iron-platinum alloy target, it can help reduce the required ordering temperature when the thin film formed by sputtering the iron-platinum alloy target is subsequently applied to a magnetic recording layer.

[0013] In some embodiments of the present invention, the iron-platinum alloy target may further comprise a nitride, and the nitride content, based on the total number of atoms in the iron-platinum alloy target, is greater than 0 at% and less than or equal to 10 at%. The nitride may comprise zirconium nitride (ZrN), aluminum nitride (AlN), titanium nitride (TiN), chromium nitride (CrN), tantalum nitride (TaN), hafnium nitride (HfN), silicon nitride (Si3N4), titanium carbonitride (TiCN), tungsten nitride (WN), vanadium nitride (VN), or combinations thereof, but is not limited thereto. By further incorporating a nitride within a specific content range into the composition of the iron-platinum alloy target, it can form a barrier between the iron-platinum grains, thereby helping to reduce the magnetic coupling effect. It should be understood that the nitride referred to in this specification does not include boron nitride, an essential component of the iron-platinum alloy target.

[0014] In some embodiments of the present invention, based on the total number of atoms of the iron-platinum alloy target material, the content of the nitride is greater than or equal to 3 at% and less than or equal to 10 at%.

[0015] In some embodiments of the present invention, the nitride comprises zirconium nitride, vanadium nitride, or a combination thereof.

[0016] Preferably, the coercivity of the thin film formed by sputtering the iron-platinum alloy target is greater than or equal to 33 kOe. More preferably, the coercivity of the thin film formed by sputtering the iron-platinum alloy target is greater than or equal to 33 kOe and less than or equal to 40 kOe.

[0017] Preferably, the saturation magnetization of the thin film formed by sputtering the iron-platinum alloy target is greater than or equal to 608 emu / cm3. More preferably, the saturation magnetization of the thin film formed by sputtering the iron-platinum alloy target is greater than or equal to 608 emu / cm3 and less than or equal to 648 emu / cm3.

[0018] Preferably, the magnetocrystalline anisotropy of the thin film sputtered from the iron-platinum alloy target is greater than or equal to 1.93 × 10⁷ erg / cm³. More preferably, the magnetocrystalline anisotropy of the thin film sputtered from the iron-platinum alloy target is greater than or equal to 1.93 × 10⁷ erg / cm³ and less than or equal to 2.26 × 10⁷ erg / cm³.

[0019] In addition, the present invention also provides a method for preparing an iron-platinum alloy target, comprising the following steps: step (a): mixing an iron raw material and an additive metal raw material, and then smelting to obtain a first pre-alloy raw material, wherein the additive metal raw material comprises a tin raw material, a zinc raw material, or a combination thereof; step (b): mixing the first pre-alloy raw material and a platinum raw material, and then smelting to obtain a second pre-alloy raw material; step (c): grinding and mixing a raw material mixture to obtain an additive raw material, wherein the raw material mixture comprises a carbon raw material and a boron nitride raw material; step (d): grinding and mixing the second pre-alloy raw material and the additive raw material to obtain an iron-platinum alloy raw material; and step (e): sintering the iron-platinum alloy raw material to obtain the iron-platinum alloy target; wherein, based on the total number of atoms of the iron-platinum alloy raw material, the content of the iron raw material is greater than or equal to 26 at% and less than or equal to 42 at%, the content of the platinum raw material is greater than or equal to 25 at% and less than or equal to 38 at%, and the content of the carbon raw material is greater than or equal to 1 at% and less than or equal to 30 at%. The boron nitride raw material has a content greater than or equal to 10 at% and less than or equal to 35 at%, and the added metal raw material has a content greater than or equal to 0.5 at% and less than or equal to 6 at%. In the X-ray diffraction pattern of the iron-platinum alloy target, there is a corresponding diffraction intensity value A at 2θ of 41.0° to 41.1° and a corresponding diffraction intensity value B at 2θ of 47.1° to 47.2°, and the ratio of the diffraction intensity value B to the diffraction intensity value A is greater than or equal to 0.13 and less than or equal to 0.33.

[0020] By simultaneously controlling the types and content ranges of specific raw materials during the fabrication process of the iron-platinum alloy target, and by preparing the first and second pre-alloyed raw materials in advance before mixing the second pre-alloyed material with the additive raw materials, the ratio of diffraction intensity values ​​within a specific 2θ range in the X-ray diffraction pattern of the prepared iron-platinum alloy target can fall within a specific range. This allows the thin film formed by sputtering to simultaneously possess good magnetic properties such as coercivity, saturation magnetization, and magnetocrystalline anisotropy.

[0021] In some embodiments of the present invention, in step (c), the raw material mixture may further include a silver raw material, and the content of the silver raw material is greater than 0 at% and less than or equal to 10 at%, based on the total number of atoms of the iron-platinum alloy raw material as a whole. In other embodiments of the present invention, the content of the silver raw material is greater than or equal to 3 at% and less than or equal to 10 at%, based on the total number of atoms of the iron-platinum alloy raw material as a whole.

[0022] In some embodiments of the present invention, in step (c), the raw material mixture may further include a nitride raw material, and the content of the nitride raw material is greater than 0 atomic percentage and less than or equal to 10 atomic percentage, based on the total number of atoms of the iron-platinum alloy raw material; the nitride raw material may include zirconium nitride raw material, aluminum nitride raw material, titanium nitride raw material, chromium nitride raw material, tantalum nitride raw material, hafnium nitride raw material, silicon nitride raw material, titanium carbonitride raw material, tungsten nitride raw material, vanadium nitride raw material or combinations thereof, but is not limited thereto.

[0023] In some embodiments of the present invention, based on the total number of atoms of the iron-platinum alloy raw material, the content of the nitride raw material is greater than or equal to 3 at% and less than or equal to 10 at%.

[0024] In some embodiments of the present invention, the nitride raw material comprises zirconium nitride raw material, vanadium nitride raw material, or a combination thereof.

[0025] According to the present invention, the form of the "raw material" can be selected according to actual needs, for example, it can be in block, flake, or powder form, but is not limited thereto. In some embodiments of the present invention, the iron raw material, the first pre-alloy raw material, and the platinum raw material can be in block form; the tin raw material and the zinc raw material can be in flake form; the second pre-alloy raw material, the carbon raw material, the boron nitride raw material, the silver raw material, the nitride raw material, and the iron-platinum alloy raw material can be in powder form.

[0026] In some embodiments of the present invention, the melting process in step (a) can be carried out in an argon (Ar) atmosphere at a pressure of 1.5 bar to 3 bar and a temperature of 950°C to 1050°C.

[0027] In some embodiments of the present invention, the melt obtained after the melting process in step (a) can be placed into a casting mold and solidified (i.e., a casting process is performed) to obtain the first pre-alloyed raw material.

[0028] In some embodiments of the present invention, the melting process in step (b) can be carried out under an argon atmosphere, a pressure of 1.5 bar to 3 bar, and a temperature of 1400°C to 1600°C.

[0029] In some embodiments of the present invention, the melt obtained after the melting process in step (b) can be subjected to a gas atomization process to obtain the second pre-alloyed raw material. The gas atomization process can be carried out under an argon atmosphere and a pressure of 5 bar to 20 bar.

[0030] In some embodiments of the present invention, the grinding and mixing process in step (c) may be carried out for 10 to 20 minutes at a rotation speed of 400 rpm to 900 rpm to obtain the added material. For example, the grinding and mixing process may be carried out using a high-speed mill under the aforementioned conditions, but is not limited thereto.

[0031] In some embodiments of the present invention, the grinding and mixing process in step (d) can be carried out at a rotation speed of 400 rpm to 900 rpm for 1 to 2 hours to obtain the iron-platinum alloy raw material. For example, the grinding and mixing process can be carried out using a high-speed grinder under the aforementioned conditions, but is not limited thereto.

[0032] Preferably, in step (d), the average particle size of the second pre-alloyed material is less than 175 micrometers (μm).

[0033] In some embodiments of the present invention, after obtaining the second pre-alloyed raw material in step (b), a sieving step can be performed, and the undersize material is taken as the second pre-alloyed raw material used in step (d); wherein, the sieve aperture used in the sieving step can be greater than or equal to 80 mesh, so that the average particle size of the undersize material is less than 175 μm.

[0034] In some embodiments of the present invention, the average particle size of the carbon raw material may be less than 10 μm, the average particle size of the boron nitride raw material may be less than 10 μm, the average particle size of the silver raw material may be less than 20 μm, and the average particle size of the nitride raw material may be less than 10 μm. In other embodiments of the present invention, the average particle size of the carbon raw material may be greater than or equal to 0.5 μm and less than 10 μm, the average particle size of the boron nitride raw material may be greater than or equal to 0.5 μm and less than 10 μm, the average particle size of the silver raw material may be greater than or equal to 1 μm and less than 20 μm, and the average particle size of the nitride raw material may be greater than or equal to 1 μm and less than 10 μm.

[0035] In some embodiments of the invention, after obtaining the iron-platinum alloy raw material in step (d) and before proceeding to step (e), a pre-compression step may be performed. This pre-compression step can be any means capable of pressing the iron-platinum alloy raw material into a fixed shape. For example, the pre-compression step may involve placing the iron-platinum alloy raw material in a hydraulic press and pre-compressing it at a pressure of approximately 250 pounds per square inch (psi) to 350 psi, but is not limited thereto.

[0036] Preferably, in step (e), the sintering process uses a pressure greater than or equal to 350 bar and less than or equal to 1800 bar, and a temperature greater than or equal to 700°C and less than or equal to 1200°C.

[0037] According to the present invention, the sintering process can be hot pressing (HP), spark plasma sintering (SPS), or hot isostatic pressing (HIP). For example, when the sintering process uses HP, the sintering temperature can be 800°C to 1200°C, the sintering pressure can be 350 bar to 400 bar, and the sintering time can be 2 hours to 4 hours, but is not limited thereto; when the sintering process uses SPS, the sintering temperature can be 700°C to 1200°C, the sintering pressure can be 1100 bar to 1200 bar, and the sintering time can be 2 hours to 4 hours, but is not limited thereto; when the sintering process uses HIP, the sintering temperature can be 700°C to 1200°C, the sintering pressure can be 1700 bar to 1800 bar, and the sintering time can be 2 hours to 4 hours, but is not limited thereto.

[0038] In this specification, the range represented by "smallest value to largest value" means, unless otherwise specified, that the range is greater than or equal to the smallest value and less than or equal to the largest value. For example, 2θ is 41.0° to 41.1°, which means that the range of 2θ is "greater than or equal to 41.0° and less than or equal to 41.1°". Simple Explanation of the Diagram

[0039] Figure 1 shows the X-ray diffraction pattern of the iron-platinum alloy target material in Example 4. Figure 2 shows the X-ray diffraction pattern of the iron-platinum alloy target material in Example 14. Figure 3 shows the X-ray diffraction pattern of the iron-platinum alloy target of Comparative Example 14. Implementation

[0040] To verify the influence of the composition of iron-platinum alloy targets, the content of each component, and the relationship between the diffraction intensity values ​​within a specific 2θ range in the X-ray diffraction pattern, several iron-platinum alloy targets are listed below as examples to illustrate the embodiments of the present invention in detail. Those skilled in the art can easily understand the advantages and effects of the present invention from the content of this specification, and can make various modifications and changes without departing from the spirit of the present invention to implement or apply the content of the present invention.

[0041] [Example] [1] [to]

[26] [Iron-platinum alloy sputtering target] [ ]

[0042] According to the composition listed in Table 1, appropriate amounts of iron blocks (purity greater than 99.95%) and zinc sheets (purity greater than 99.95%) and / or tin sheets (purity greater than 99.95%) as additive metal raw materials are weighed and placed in a crucible. A vacuum is then applied to a pressure of approximately 1×10⁻² mbar to 1×10⁻³ mbar. Argon gas is then introduced to a pressure of approximately 1.5 bar to 3 bar, followed by heating to 950°C to 1050°C for melting. After melting, a casting process is performed, whereby the molten material is rapidly poured into a preheated casting mold (e.g., a metal mold or a water-cooled mold) and allowed to solidify. After cooling, the material is removed, and any residual oxide scale on the surface is removed to obtain the first pre-alloyed material. The composition of the first pre-alloyed material can be an iron-zinc alloy, an iron-tin alloy, or an iron-zinc-tin alloy.

[0043] Next, according to the composition listed in Table 1, an appropriate amount of platinum ingots (purity greater than 99.95%) were weighed and placed together with the aforementioned first pre-alloying raw material (cut into blocks) in a crucible. A vacuum was then drawn to a pressure of approximately 1×10⁻² mbar to 1×10⁻³ mbar, followed by the introduction of argon gas to a pressure of approximately 1.5 bar to 3 bar, and then heated to 1400°C to 1600°C for melting. After melting, a gas atomization process was performed, in which the melt was placed in an atomization chamber filled with argon gas and atomized into powder at a pressure of 5 bar to 20 bar. The powder was then collected using a cyclone separator to obtain the second pre-alloying raw material. The composition of the second pre-alloying raw material can be an iron-platinum-zinc alloy, an iron-platinum-tin alloy, or an iron-platinum-zinc-tin alloy.

[0044] Next, according to the composition listed in Table 1, appropriate amounts of carbon powder (average particle size less than 10 μm), boron nitride powder (average particle size less than 10 μm), silver powder (average particle size less than 20 μm), vanadium nitride powder (average particle size less than 10 μm), and / or zirconium nitride powder (average particle size less than 10 μm) were weighed and placed in a high-speed grinder and ground and mixed for 10 minutes at a speed of 400 rpm to 900 rpm to obtain a raw material mixture. On the other hand, the above-mentioned second pre-alloyed raw material was passed through a sieve with a mesh size of approximately 80 mesh, and the powder passing through the sieve was collected to make the average particle size of the second pre-alloyed raw material less than 175 μm. Subsequently, it was placed together with the aforementioned raw material mixture in a high-speed grinder and ground and mixed for 1 hour at a speed of 400 rpm to 900 rpm to obtain an iron-platinum alloy raw material.

[0045] Next, the aforementioned iron-platinum alloy raw material was placed in a hydraulic press and pre-pressed at a pressure of approximately 300 psi. Then, sintering was performed according to the sintering process and sintering temperature listed in Table 1 below to obtain the iron-platinum alloy targets of Examples 1 to 26. Wherein, if the sintering process is HP, the sintering pressure is approximately 380 bar and the sintering time is approximately 3 hours; if the sintering process is SPS, the sintering pressure is approximately 1150 bar and the sintering time is approximately 3 hours; if the sintering process is HIP, the sintering pressure is approximately 1750 bar and the sintering time is approximately 3 hours.

[0046] In Table 1 below, the composition of the iron-platinum alloy targets of Examples 1 to 26 can be represented by the general formula aFe-bPt-cC-dBN-e1Sn-e2Zn-fAg-g1VN-g2ZrN; where a represents the content ratio of iron relative to the total number of atoms in the iron-platinum alloy target, b represents the content ratio of platinum relative to the total number of atoms in the iron-platinum alloy target, c represents the content ratio of carbon relative to the total number of atoms in the iron-platinum alloy target, d represents the content ratio of boron nitride relative to the total number of atoms in the iron-platinum alloy target, e1 to e2 represent the content ratios of tin and zinc relative to the total number of atoms in the iron-platinum alloy target, f represents the content ratio of silver relative to the total number of atoms in the iron-platinum alloy target, and g1 to g2 represent the content ratios of vanadium nitride and zirconium nitride relative to the total number of atoms in the iron-platinum alloy target. In this specification, the "content of added metals" refers to the sum of e1 to e2, and the "content of nitrides" refers to the sum of g1 to g2.

[0047] [Comparative Example] [1] [to]

[29] [Iron-platinum alloy sputtering target] [ ]

[0048] Comparative Examples 1 to 29 were first prepared using the same method as in Examples 1 to 29 to obtain a second pre-alloying material (average particle size less than 175 μm). Then, according to the composition listed in Table 1, appropriate amounts of carbon powder (average particle size less than 10 μm), boron nitride powder (average particle size less than 10 μm), silver powder (average particle size less than 20 μm), vanadium nitride powder (average particle size less than 10 μm), zirconium nitride powder (average particle size less than 10 μm), germanium (Ge) powder (average particle size less than 15 μm), and / or silicon dioxide (SiO2) powder (average particle size less than 1 μm) were weighed and mixed manually with the aforementioned second pre-alloying material. This mixture was then placed in an automatic powder mixer (manufacturer: RETSCH, Germany; model: RM24) for 1 hour of rolling mixing to obtain a iron-platinum alloy material. Subsequently, the iron-platinum alloy targets of Comparative Examples 1 to 29 were prepared using the same pre-pressing and sintering process as in Examples 2 to 29.

[0049] The composition of the iron-platinum alloy targets of Comparative Examples 1 to 29 and the content of each component in atomic percentage are listed in Table 1 below. The iron-platinum alloy targets of Comparative Examples 1 to 29 can also be represented by the general formula as described in the aforementioned embodiments, namely, aFe-bPt-cC-dBN-e1Sn-e2Zn-fAg-g1VN-g2ZrN-hGe-iSiO2; wherein, a to d, e1, e2, f, g1 and g2 represent the same meaning as described in the aforementioned embodiments, and h represents the content ratio of germanium relative to the total number of atoms of the iron-platinum alloy target, and i represents the content ratio of silicon dioxide relative to the total number of atoms of the iron-platinum alloy target. Table 1: Composition of the iron-platinum alloy targets of Examples 1 to 26 (referred to as E1 to E26) and Comparative Examples 1 to 29 (referred to as C1 to C29), and the selected sintering process and sintering temperature. [composition] [Composition of iron-platinum alloy sputtering target] [sintering] [Manufacturing Process] [temperature] [(°C)] E1 26Fe-26Pt-29C-18BN-1Zn HP 1200 E2 32Fe-25Pt-30C-11BN-2Zn HIP 1200 E3 28Fe-30Pt-5C-35BN-2Zn SPS 1200 E4 29Fe-27Pt-8C-30BN-6Zn SPS 1000 E5 29Fe-27Pt-8C-30BN-6Sn SPS 1000 E6 30Fe-38Pt-18.5C-10BN-0.5Sn-3Zn HP 700 E7 42Fe-30Pt-1C-25BN-1.5Sn-0.5Zn SPS 700 E8 32Fe-26Pt-30C-11.5BN-0.5Sn HIP 700 E9 37Fe-27Pt-6C-23BN-4Zn-3VN SPS 950 E10 30Fe-32Pt-6C-20BN-2Sn-10VN SPS 1000 E11 35Fe-31Pt-10C-20BN-4Sn SPS 900 E12 26Fe-26Pt-30C-15BN-2Zn-1Ag HIP 1200 E13 31Fe-26Pt-5C-34BN-2Zn-2Ag SPS 1200 E14 29Fe-27Pt-8C-30BN-3Zn-3Ag SPS 1000 E15 28Fe-30Pt-1C-35BN-2Zn-4Ag SPS 1000 E16 32Fe-26Pt-6C-28BN-5Zn-3Ag SPS 950 E17 32Fe-26Pt-6C-28BN-4Zn-4Ag SPS 950 E18 35Fe-25Pt-20C-11BN-2Zn-7Ag HP 1200 E19 30Fe-32Pt-12C-15BN-5Sn-6Ag HP 800 E20 35Fe-29Pt-6C-20BN-2Sn-8Ag SPS 900 E21 32Fe-30Pt-15C-10BN-3Zn-10Ag HP 700 E22 30Fe-38Pt-12C-10BN-0.5Sn-3Zn-6.5Ag HIP 700 E23 42Fe-30Pt-1C-20BN-1.5Sn-0.5Zn-5Ag SPS 700 E24 33Fe-27Pt-6C-23BN-4Zn-6Ag-3ZrN HIP 1000 E25 33Fe-27Pt-6C-23BN-4Zn-4Ag -3VN HIP 1000 E26 30Fe-32Pt-6C-18BN-2Sn-2Ag-10VN SPS 1000 C1 20Fe-40Pt-8C-22BN-5Zn-5Sn SPS 800 C2 44Fe-26Pt-15C-10BN-5Zn HP 700 C3 28Fe-26Pt-31C-10BN-1Zn HIP 1200 C4 24Fe-24Pt-40BN-12Sn SPS 1200 C5 35Fe-32Pt-25C-5BN-3Sn HP 850 C6 26Fe-26Pt-2C-38BN-8Zn SPS 1200 C7 26Fe-26Pt-30C-18BN HP 1200 C8 27Fe-26Pt-10C-30BN-7Zn SPS 1200 C9 35Fe-25Pt-10C-24BN-6Sn SPS 900 C10 43Fe-27Pt-15C-10BN-3Zn-2Ag HP 700 C11 37Fe-37Pt-10BN-10Zn-6Ag SPS 700 C12 35Fe-32Pt-25C-5BN-2Sn-1Ag HP 850 C13 31Fe-26Pt-5C-34BN-4Ag HIP 1000 C14 29Fe-27Pt-8C-30BN-6Ag SPS 1000 C15 28Fe-30Pt-1C-35BN-6Ag SPS 1000 C16 32Fe-26Pt-6C-28BN-8Ag SPS 900 C17 30Fe-32Pt-12C-20BN-6Ag SPS 850 C18 35Fe-25Pt-20C-11BN-9Ag HP 900 C19 35Fe-29Pt-6C-20BN-10Ag HIP 800 C20 42Fe-30Pt-1C-20BN-7Ag SPS 700 C21 27Fe-26Pt-8C-30BN-7Zn-2Ag HP 1000 C22 35Fe-25Pt-5C-24BN-6Sn-5Ag SPS 800 C23 33Fe-27Pt-6C-23BN-8Ag-3VN HP 1000 C24 33Fe-27Pt-6C-23BN-8Ag-3ZrN HP 1000 C25 30Fe-32Pt-6.5C-19BN-0.5Sn-12VN HIP 900 C26 25Fe-24Pt-36C-9BN-6Sn HIP 1200 C27 27Fe-27Pt-40C-3Zn-3Ge HIP 1200 C28 35Fe-35Pt-10BN-10Zn-10SiO2 SPS 700 C29 25Fe-39Pt-10BN-8Sn-8Zn-10VN SPS 700

[0050] [analyze] [1] [:] [X] [In the ray diffraction pattern] [specific] [2θ] [Within the range] [Diffraction] [Intensity Value] [Relationship] [analyze] [ ]

[0051] This analysis used iron-platinum alloy targets from Examples 1 to 26 and Comparative Examples 1 to 29 as test samples. Each sample was analyzed using an X-ray diffractometer (hereinafter referred to as XRD; manufacturer: Rigaku, model: Ultima IV). The relationship between the diffraction intensity value (i.e., diffraction intensity value A) at approximately 2θ of 41.049° and the diffraction intensity value (i.e., diffraction intensity value B) at approximately 2θ of 47.123° was then determined in the X-ray diffraction pattern.

[0052] Specifically, the iron-platinum alloy targets of Examples 1 to 26 and Comparative Examples 1 to 29 were first wire-cut to obtain test pieces with a size of 5 mm × 5 mm × 5 mm. After the test pieces were polished with sandpaper, they were placed in an XRD machine and measured with a step angle of 0.04° (° / step) in a scanning range of 2θ from 20° to 80°.

[0053] The following description uses the results of the iron-platinum alloy targets of Example 4, Example 14 and Comparative Example 14 as examples. Their respective X-ray diffraction patterns are shown in Figures 1 to 3 in sequence. Each pattern was compared and identified using the XRD analysis software "Jade". The standard pattern of iron-platinum crystallization (card number 43-1359) is listed below the XRD pattern.

[0054] As can be seen from Figures 1 and 2, the spectra of Examples 4 and 14 show obvious characteristic peaks at the (111) crystal plane of the corresponding iron-platinum crystal (i.e., at 2θ of approximately 41.049°); and also at the (200) crystal plane of the corresponding iron-platinum crystal (i.e., at 2θ of approximately 47.123°), and these characteristic peaks are obviously shifted to the left (i.e. to the direction of 2θ, which is a smaller angle).

[0055] Looking at Figure 3 again, a distinct characteristic peak can be observed at the (111) crystal plane of the corresponding iron-platinum crystal (i.e., at 2θ of approximately 41.049°); and a distinct characteristic peak can also be observed at the (200) crystal plane of the corresponding iron-platinum crystal (i.e., at 2θ of approximately 47.123°), and this characteristic peak has not shifted significantly.

[0056] To quantify the relationship between the aforementioned diffraction intensity values ​​A and B, this analysis further uses diffraction intensity value B as the numerator and diffraction intensity value A as the denominator, and divides the two to obtain the ratio of diffraction intensity value B to diffraction intensity value A, so as to specifically evaluate the relationship between the two. The results of Examples 1 to 26 and Comparative Examples 1 to 29 are all listed in Table 2 below and labeled as "B / A ratio". Taking the results of Examples 4, 14, and Comparative Example 14 as examples, the diffraction intensity value at 2θ of approximately 41.049° in the spectrum of Example 4 is 187.5 and the diffraction intensity value at 2θ of approximately 47.123° is 23.75. Therefore, the B / A ratio of Example 4 in Table 2 is 0.13. In the spectrum of Example 14, the diffraction intensity value at 2θ of approximately 41.049° is 181.25 and the diffraction intensity value at 2θ of approximately 47.123° is 43.50. Therefore, the B / A ratio of Example 14 in Table 2 is 0.24. In the spectrum of Comparative Example 14, the diffraction intensity value at 2θ of approximately 41.049° is 141.0 and the diffraction intensity value at 2θ of approximately 47.123° is 49.0. Therefore, the B / A ratio of Comparative Example 14 in Table 2 is 0.35.

[0057] [analyze] [2] [Magnetic Properties Analysis] [ ]

[0058] First, the iron-platinum alloy targets of Examples 1 to 26 and Comparative Examples 1 to 29 were further processed by wire cutting and lathe to obtain circular targets with a diameter of 2 inches and a thickness of 3 millimeters. Then, the targets were placed in a magnetron sputtering machine (Golden Technology) to pre-sputter them to remove dirt from the surface of the targets in order to obtain the targets to be sputtered.

[0059] Subsequently, the sputtering target was sputtered onto a substrate at a working vacuum of 1×10⁻³ torr and a power of 30 watts (W) to obtain a thin film. The sputtering time was adjusted according to the measured deposition rate to achieve a film thickness of 15 nanometers (nm). The substrate was a magnesium oxide (100) single-crystal wafer with a diameter of 1 cm and a thickness of 1 cm, on which a 1 nm thick iron-platinum layer had been pre-sputtered as an initial nucleation layer. The base vacuum during sputtering was 1×10⁻⁷ torr, and the film was heated at a fixed temperature of 700°C during deposition. After deposition, an annealing treatment was performed at 700°C for 10 minutes to obtain a sample with the magnetic properties to be measured.

[0060] Subsequently, the samples with the magnetic properties to be measured were placed in a superconducting quantum interference device (SQUID; manufacturer: Quantum Design, model: MPMS-3). The magnetization of each sample under different magnetic field intensities was measured at a magnetic field strength of ±7 Tesla (T) (i.e., ±70,000 Gauss (G)) and room temperature. The results of the coercivity (Hc), saturation magnetization (Ms), and magnetocrystalline anisotropy (Ku) were obtained by calculating the measured hysteresis curves. Here, Ku = 1 / 2 (Hk × Ms), and Hk is the magnetic field strength H value corresponding to 0.95 times Ms in the hysteresis curve. The results of Examples 1 to 26 and Comparative Examples 1 to 29 are shown in Table 2 below. Table 2: Composition of iron-platinum alloy targets, their B / A ratios, and magnetic properties of the sputtered thin films of Examples 1 to 26 (referred to as E1 to E26) and Comparative Examples 1 to 29 (referred to as C1 to C29). [composition] [Composition of iron-platinum alloy sputtering target] [B / A] [ratio] [Magnetic properties] [Hc] [(kOe)] [Ms] [(emu / cm, 3 , )] [Ku] [(×10, 7 , erg / cm, 3 )] E1 26Fe-26Pt-29C-18BN-1Zn 0.33 33 627 1.93 E2 32Fe-25Pt-30C-11BN-2Zn 0.27 36.5 648 1.94 E3 28Fe-30Pt-5C-35BN-2Zn 0.28 33.6 608 1.97 E4 29Fe-27Pt-8C-30BN-6Zn 0.13 40 641 2.26 E5 29Fe-27Pt-8C-30BN-6Sn 0.14 38.5 639 2.2 E6 30Fe-38Pt-18.5C-10BN-0.5Sn-3Zn 0.23 34.8 609 1.93 E7 42Fe-30Pt-1C-25BN-1.5Sn-0.5Zn 0.29 36.9 639 1.96 E8 32Fe-26Pt-30C-11.5BN-0.5Sn 0.33 34 619 1.95 E9 37Fe-27Pt-6C-23BN-4Zn-3VN 0.18 38 645 2.4 E10 30Fe-32Pt-6C-20BN-2Sn-10VN 0.26 41 610 2.3 E11 35Fe-31Pt-10C-20BN-4Sn 0.17 33 614 1.99 E12 26Fe-26Pt-30C-15BN-2Zn-1Ag 0.28 34.9 625 2.04 E13 31Fe-26Pt-5C-34BN-2Zn-2Ag 0.30 35 624 1.99 E14 29Fe-27Pt-8C-30BN-3Zn-3Ag 0.24 37.5 632 2.1 E15 28Fe-30Pt-1C-35BN-2Zn-4Ag 0.28 33 615 2.08 E16 32Fe-26Pt-6C-28BN-5Zn-3Ag 0.16 40 637 2.12 E17 32Fe-26Pt-6C-28BN-4Zn-4Ag 0.20 37.1 648 2.26 E18 35Fe-25Pt-20C-11BN-2Zn-7Ag 0.27 34.9 635 1.95 E19 30Fe-32Pt-12C-15BN-5Sn-6Ag 0.18 37.5 609 2.15 E20 35Fe-29Pt-6C-20BN-2Sn-8Ag 0.32 36.7 627 2.14 E21 32Fe-30Pt-15C-10BN-3Zn-10Ag 0.25 38.1 631 2.11 E22 30Fe-38Pt-12C-10BN-0.5Sn-3Zn-6.5Ag 0.22 35.1 608 1.98 E23 42Fe-30Pt-1C-20BN-1.5Sn-0.5Zn-5Ag 0.30 36.8 640 1.93 E24 33Fe-27Pt-6C-23BN-4Zn-6Ag-3ZrN 0.21 35.4 614 2.03 E25 33Fe-27Pt-6C-23BN-4Zn-4Ag-3VN 0.22 39 619 2.2 E26 30Fe-32Pt-6C-18BN-2Sn-2Ag-10VN 0.26 41 613 2.3 C1 20Fe-40Pt-8C-22BN-5Zn-5Sn 0.11 20.9 421 0.98 C2 44Fe-26Pt-15C-10BN-5Zn 0.10 0.7 678 0.07 C3 28Fe-26Pt-31C-10BN-1Zn 0.34 27.5 560 1.43 C4 24Fe-24Pt-40BN-12Sn 0.10 22.8 446 1.54 C5 35Fe-32Pt-25C-5BN-3Sn 0.34 31.6 568 1.83 C6 26Fe-26Pt-2C-38BN-8Zn 0.12 24.7 458 1.51 C7 26Fe-26Pt-30C-18BN 0.36 26.8 521 1.65 C8 27Fe-26Pt-10C-30BN-7Zn 0.11 31.8 503 1.76 C9 35Fe-25Pt-10C-24BN-6Sn 0.12 29.8 605 2.4 C10 43Fe-27Pt-15C-10BN-3Zn-2Ag 0.10 0.8 680 0.06 C11 37Fe-37Pt-10BN-10Zn-6Ag 0.11 24.5 471 1.57 C12 35Fe-32Pt-25C-5BN-2Sn-1Ag 0.34 28.4 563 1.48 C13 31Fe-26Pt-5C-34BN-4Ag 0.39 31 576 1.74 C14 29Fe-27Pt-8C-30BN-6Ag 0.35 30 535 1.89 C15 28Fe-30Pt-1C-35BN-6Ag 0.44 28.6 468 1.64 C16 32Fe-26Pt-6C-28BN-8Ag 0.44 32.8 604 1.88 C17 30Fe-32Pt-12C-20BN-6Ag 0.41 24.1 465 1.6 C18 35Fe-25Pt-20C-11BN-9Ag 0.43 27.6 588 1.68 C19 35Fe-29Pt-6C-20BN-10Ag 0.48 26.8 581 1.58 C20 42Fe-30Pt-1C-20BN-7Ag 0.40 29 581 1.67 C21 27Fe-26Pt-8C-30BN-7Zn-2Ag 0.11 32 485 1.57 C22 35Fe-25Pt-5C-24BN-6Sn-5Ag 0.12 30.7 602 2.45 C23 33Fe-27Pt-6C-23BN-8Ag-3VN 0.46 31.7 600 1.55 C24 33Fe-27Pt-6C-23BN-8Ag-3ZrN 0.48 28.6 595 1.92 C25 30Fe-32Pt-6.5C-19BN-0.5Sn-12VN 0.35 24.2 603 1.81 C26 25Fe-24Pt-36C-9BN-6Sn 0.13 19.7 480 1.03 C27 27Fe-27Pt-40C-3Zn-3Ge 0.38 26.7 472 1.52 C28 35Fe-35Pt-10BN-10Zn-10SiO2 0.07 25.4 467 1.63 C29 25Fe-39Pt-10BN-8Sn-8Zn-10VN 0.09 23.2 427 0.94

[0061] [Discussion of Experimental Results] [ ]

[0062] According to the manufacturing process of each embodiment and the results in Table 2, by employing at least the following techniques simultaneously: (1) controlling the specific types of raw materials, (2) controlling the content range of each raw material, (3) grinding and mixing the raw material mixture to obtain the additive material, and (4) grinding and mixing the second pre-alloyed material with the additive material, the resulting iron-platinum alloy target material can simultaneously possess the following technical characteristics: (I) iron content greater than or equal to 26 at% and less than or equal to 42 at%, (II) platinum content greater than or equal to 25 at% and less than or equal to 38 at%, (III) carbon content greater than or equal to 1 at% and less than or equal to 30 at%, (IV) boron nitride content greater than or equal to 10 at% and less than or equal to 35 at%, (V) the content of the additive metal greater than or equal to 0.5 at% and less than or equal to 6 at%. At% and (VI) In the X-ray diffraction pattern, the ratio of the diffraction intensity value B to the diffraction intensity value A is greater than or equal to 0.13 and less than or equal to 0.33. Accordingly, the thin films obtained by sputtering the iron-platinum alloy targets of Examples 1 to 26 can simultaneously possess good magnetic properties of Hc greater than or equal to 33 kOe, Ms greater than or equal to 608 emu / cm3 and Ku greater than or equal to 1.93×107 erg / cm3.

[0063] In contrast, none of the comparative examples 1 to 29 simultaneously employed the aforementioned technical means (1) to (4). Therefore, the iron-platinum alloy targets of comparative examples 1 to 29 could not simultaneously possess the aforementioned technical features (I) to (VI), resulting in the thin films obtained by sputtering using the iron-platinum alloy targets of comparative examples 1 to 29 not simultaneously possessing good magnetic properties of Hc, Ms and Ku.

[0064] Therefore, the technical means and solutions provided by the present invention can enable the thin film sputtered from the iron-platinum alloy target to have good magnetic properties of Hc, Ms and Ku, and thus be suitable as a magnetic recording layer and can be applied to heat-assisted magnetic recording media that require higher recording density.

[0065] Furthermore, referring to Comparative Examples 7, 13 to 20, 23 and 24, although the content ranges of iron, platinum, carbon, boron nitride, silver and / or nitrides in the iron-platinum alloy targets of these examples all conform to the specific ranges defined in this invention, since Comparative Examples 7, 13 to 20, 23 and 24 did not add specific types and content ranges of additive metals (i.e. tin, zinc or combinations thereof) to their compositions, and their B / A ratios were not within the range of greater than or equal to 0.13 and less than or equal to 0.33 as defined in this invention, the films obtained by sputtering the iron-platinum alloy targets of Comparative Examples 7, 13 to 20, 23 and 24 could not exceed 31.7 kOe, Ms could not exceed 604 emu / cm3 and Ku could not exceed 1.92×107 erg / cm3.

[0066] Furthermore, referring to Comparative Examples 8 and 21, although the iron-platinum alloy targets of these groups contain zinc as an additive metal, since the content of the additive metal in Comparative Examples 8 and 21 is higher than the content range defined by the present invention, and their B / A ratios are also lower than the range defined by the present invention, the films obtained by sputtering the iron-platinum alloy targets of Comparative Examples 8 and 21 cannot have Hc higher than 32 kOe, Ms higher than 503 emu / cm3, and Ku higher than 1.76×107 erg / cm3.

[0067] Furthermore, referring to Comparative Examples 9 and 22, although the composition and content range of the iron-platinum alloy targets in these groups all conform to the specific range defined by the present invention, the B / A ratio of the iron-platinum alloy targets in Comparative Examples 9 and 22 is less than 0.13, which is outside the range of greater than or equal to 0.13 and less than or equal to 0.33 defined by the present invention. Therefore, the thin films obtained by sputtering the iron-platinum alloy targets in Comparative Examples 9 and 22 still cannot simultaneously possess the good magnetic properties of Hc greater than or equal to 33 kOe, Ms greater than or equal to 608 emu / cm3 and Ku greater than or equal to 1.93×107 erg / cm3.

[0068] In summary, by controlling the composition of the iron-platinum alloy target material to contain specific types and ranges of components, and simultaneously controlling the ratio of diffraction intensity values ​​within a specific 2θ range in its X-ray diffraction pattern, the present invention enables the thin film sputtered using the iron-platinum alloy target material of the present invention to have excellent magnetic properties. Therefore, it can be used as a magnetic recording layer in heat-assisted magnetic recording media with higher recording density, in line with future development trends and further enhancing its commercial value.

[0069] none.

[0070] none.

Claims

1. A ferroplatinum alloy target comprising iron, platinum, carbon, boron nitride, and an additive metal comprising tin, zinc, or a combination thereof; wherein, Based on the total number of atoms of the iron-platinum alloy target, the iron content is greater than or equal to 26 atomic percent and less than or equal to 42 atomic percent, the platinum content is greater than or equal to 25 atomic percent and less than or equal to 38 atomic percent, the carbon content is greater than or equal to 1 atomic percent and less than or equal to 30 atomic percent, the boron nitride content is greater than or equal to 10 atomic percent and less than or equal to 35 atomic percent, and the content of the added metal is greater than or equal to 0.5 atomic percent and less than or equal to 6 atomic percent. In the X-ray diffraction pattern of the iron-platinum alloy target, there is a corresponding diffraction intensity value A at 2θ of 41.0° to 41.1°, and a corresponding diffraction intensity value B at 2θ of 47.1° to 47.2°, and the ratio of the diffraction intensity value B to the diffraction intensity value A is greater than or equal to 0.13 and less than or equal to 0.

33.

2. The iron-platinum alloy target as described in claim 1, wherein, The iron-platinum alloy target also contains silver, and based on the total number of atoms in the iron-platinum alloy target, the silver content is greater than 0 atomic percentage and less than or equal to 10 atomic percentage.

3. The iron-platinum alloy target material as described in claim 1, wherein, The iron-platinum alloy target also contains silver, and based on the total number of atoms in the iron-platinum alloy target, the silver content is greater than or equal to 3 atomic percent and less than or equal to 10 atomic percent.

4. The iron-platinum alloy target as described in claim 1 or 2, wherein, The iron-platinum alloy target also contains a nitride, and based on the total number of atoms of the iron-platinum alloy target, the content of the nitride is greater than 0 atomic percentage and less than or equal to 10 atomic percentage; the nitride includes zirconium nitride, aluminum nitride, titanium nitride, chromium nitride, tantalum nitride, hafnium nitride, silicon nitride, titanium carbonitride, tungsten nitride, vanadium nitride, or combinations thereof.

5. A method for preparing an iron-platinum alloy target, comprising the following steps: Step (a): mixing an iron raw material and an additive metal raw material, followed by smelting to obtain a first pre-alloyed raw material, wherein, The added metal raw material includes a tin raw material, a zinc raw material, or a combination thereof; Step (b): Mix the first pre-alloy raw material and a platinum raw material, and then smelt them to obtain a second pre-alloy raw material; Step (c): Grind and mix a raw material mixture to obtain an additive raw material, wherein the raw material mixture contains a carbon raw material and a boron nitride raw material; Step (d): Grind and mix the second pre-alloy raw material and the additive raw material to obtain an iron-platinum alloy raw material; and Step (e): Sinter the iron-platinum alloy raw material to obtain the iron-platinum alloy target; wherein, based on the total number of atoms of the iron-platinum alloy raw material, the content of the iron raw material is greater than or equal to 26 atomic percent and less than or equal to 42 atomic percent, the content of the platinum raw material is greater than or equal to 25 atomic percent and less than or equal to 38 atomic percent, the content of the carbon raw material is greater than or equal to 1 atomic percent and less than or equal to 30 atomic percent, the content of the boron nitride raw material is greater than or equal to 10 atomic percent and less than or equal to 35 atomic percent, and the content of the additive metal raw material is greater than or equal to 0.5 atomic percent and less than or equal to 6 atomic percent; In the X-ray diffraction pattern of the iron-platinum alloy target, there is a corresponding diffraction intensity value A at 2θ of 41.0° to 41.1° and a corresponding diffraction intensity value B at 2θ of 47.1° to 47.2°, and the ratio of the diffraction intensity value B to the diffraction intensity value A is greater than or equal to 0.13 and less than or equal to 0.

33.

6. The manufacturing method as described in claim 5, wherein, In step (c), the raw material mixture also contains a silver raw material, and the content of the silver raw material is greater than 0 atomic percentage and less than or equal to 10 atomic percentage, based on the total number of atoms of the iron-platinum alloy raw material as a whole.

7. The manufacturing method as described in claim 6, wherein, Based on the total number of atoms in the iron-platinum alloy raw material, the content of the silver raw material is greater than or equal to 3 atomic percentages and less than or equal to 10 atomic percentages.

8. The manufacturing method as described in claim 5 or 6, wherein, In step (c), the raw material mixture further comprises a nitride raw material, and the content of the nitride raw material is greater than 0 atomic percentage and less than or equal to 10 atomic percentage, based on the total number of atoms of the iron-platinum alloy raw material; the nitride raw material comprises zirconium nitride, aluminum nitride, titanium nitride, chromium nitride, tantalum nitride, hafnium nitride, silicon nitride, titanium carbide nitride, tungsten nitride, vanadium nitride, or a combination thereof.

9. The manufacturing method as described in claim 5, wherein, In step (d), the average particle size of the second pre-alloyed material is less than 175 micrometers.

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