Magnetic material targets and magnetic material target assemblies

Abstract

The present invention provides a magnetic material target and a magnetic material target assembly that enable the fabrication of thin films with small Dn (magnetic cluster size) and excellent Hc (coercivity). [Solution] A magnetic material target comprising one or more of Pt and B, Mo, an oxide, with the remainder being Co and selectively included impurities, wherein the combined concentration of Co and Pt is 50 at% or more, the combined concentration of B and Mo is 10 at% or more, and the concentration of O is 20 at% or more.

Description

Technical Field

[0001] The present invention relates to a magnetic material target and a magnetic material target assembly.

Background Art

[0002] In the layers constituting a hard disk drive (HDD) employing a perpendicular magnetic recording method, for example, materials based on ferromagnetic metals such as Co, Fe, and Ni are used. In the recording layer, composite materials composed of ferromagnetic alloys mainly containing Co, such as Co-Cr-based, Co-Pt-based, and Co-Cr-Pt-based, and non-magnetic inorganic materials are often used. Thin films of magnetic recording media such as such hard disk drives are often produced by sputtering a magnetic material target containing the above materials as components due to high productivity.

[0003] The production of a magnetic material target generally first obtains a sintered body by hot pressing a mixture obtained by pulverizing and mixing raw material powders. After that, HIP (Hot Isostatic Pressing) processing may be performed to improve the density of the sintered body. The sintered body thus obtained is processed by a lathe to manufacture a target having a predetermined shape (Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] A composite material consisting of a ferromagnetic alloy with Co as the main component and a non-magnetic inorganic material is useful as the recording layer of an HDD. HDD media manufacturers sputter-deposit this material to create a thin film with a granular structure in which magnetic particles are separated by oxide grain boundaries.

[0006] In thin films used in the recording layer of HDDs, increasing the temperature of the thin film (increasing the heating time) makes it easier for the Co-Pt hcp structure to become more orderly, but it also creates a problem where oxide grain boundary material penetrates the magnetic particles. When oxide grain boundary material penetrates the magnetic particles, the recording density of the HDD recording layer decreases. For this reason, there is a need for thin film materials that do not allow oxide grain boundary material to penetrate even when heated, i.e., thin films with a small Dn (magnetic cluster size). Furthermore, for the recording layer of an HDD, it is also an important function to retain the recorded data, so the development of thin film materials with excellent Hc (retention force) is also eagerly awaited.

[0007] Therefore, the object of the embodiments of the present invention is to provide a magnetic material target and a magnetic material target assembly that can produce a thin film with a small Dn (magnetic cluster size) and excellent Hc (coercivity). [Means for solving the problem]

[0008] The above problems are solved by the present invention, which is defined as follows. 1. It contains one or more of Pt and B, Mo, an oxide, and the remainder is Co and selectively included impurities. The combined concentration of Co and Pt is 50 at% or more. The sum of the concentrations of B and Mo is 10 at% or more. A magnetic material target with an O concentration of 20 at% or more. 2. The magnetic material target according to claim 1, wherein the oxide further contains one or more oxides of elements selected from Al, Si, Ba, Be, Ca, Ce, Cr, Co, Dy, Er, Eu, Ga, Ho, Li, Mg, Mn, Nb, Nd, Pr, Sc, Sm, Sr, Ta, Tb, Ti, V, Y, Zn, and Zr. 3. A magnetic material target as described in 1 or 2 above, A backing plate bonded to the magnetic material target, A magnetic material target assembly equipped with the following features. [Effects of the Invention]

[0009] According to embodiments of the present invention, it is possible to provide a magnetic material target and a magnetic material target assembly that can produce a thin film with a small Dn (magnetic cluster size) and excellent Hc (coercivity). [Brief explanation of the drawing]

[0010] [Figure 1] This graph shows the results of the Hc (holding power) evaluation tests for Example 1, Comparative Examples 1 and 2. [Figure 2] This graph shows the results of the Dn (magnetic cluster size) evaluation tests for Example 1, Comparative Examples 1 and 2. [Modes for carrying out the invention]

[0011] Next, embodiments for carrying out the present invention will be described in detail. The present invention is not limited to the following embodiments, and it should be understood that appropriate design changes, improvements, etc., can be made based on the ordinary knowledge of those skilled in the art, without departing from the spirit of the invention.

[0012] <Magnetic material target> The shape of the magnetic material target according to the embodiment of the present invention is not particularly limited, but may be flat (including disc-shaped or rectangular plate-shaped), cylindrical, or any other shape.

[0013] The magnetic material target according to the embodiment of the present invention comprises one or more of Pt and B, Mo, an oxide, and the remainder being Co and selectively included impurities. By using the magnetic material target according to the embodiment of the present invention as a sputtering target, thin films for magnetic recording media such as hard disk drives (HDDs) can be fabricated.

[0014] In the embodiment of the present invention, the magnetic material target has a total concentration of Co and Pt of 50 at% or more. A total concentration of Co and Pt in the magnetic material target of 50 at% or more improves magnetic properties in that a certain level of magnetization can be ensured. While there is no particular upper limit to the total concentration of Co and Pt in the magnetic material target, it is preferable to have a total concentration of 90 at% or less from the viewpoint of ensuring grain boundary material. Furthermore, the total concentration of Co and Pt in the magnetic material target is more preferably 50 to 85 at%, and even more preferably 50 to 80 at%.

[0015] In the magnetic material target according to the embodiment of the present invention, the combined concentration of B and Mo is 10 at% or more, and the concentration of O is 20 at% or more. With such a configuration, B, Mo, and O readily form oxide grain boundaries in a granular structure where magnetic particles are separated by oxide grain boundaries, thus enabling the production of a desirable magnetic thin film. In the magnetic material target according to the embodiment of the present invention, the combined concentration of B and Mo is preferably 10 to 15 at%, and more preferably 10 to 13 at%. In the magnetic material target according to the embodiment of the present invention, the concentration of O is preferably 20 to 35 at%, and more preferably 25 to 30 at%.

[0016] According to the magnetic material target according to an embodiment of the present invention, a thin film with a small Dn (magnetic cluster size) and excellent Hc (coercive force) can be produced. In the thin film used for the recording layer of an HDD, when the temperature of the thin film is increased (when the heating time is increased), while the hcp structure of Co-Pt tends to be regularized, an oxide grain boundary material enters the magnetic particles, resulting in a problem that the recording density of the recording layer of the HDD decreases. On the other hand, in the magnetic material target according to an embodiment of the present invention, due to reasons such as the strong binding force between molybdenum ions and oxygen ions, for example, even in a high-temperature state of 230 to 250 ° C, a film with a small Dn (magnetic cluster size) and a high Hc (coercive force) can be formed. The Dn (magnetic cluster size) of the thin film produced using the magnetic material target according to an embodiment of the present invention is preferably 10 to 20 nm, more preferably 10 to 18 nm, and even more preferably 10 to 16 nm. The Hc (coercive force) of the thin film produced using the magnetic material target according to an embodiment of the present invention is preferably 9 to 15 kOe, more preferably 10 to 15 kOe, and even more preferably 11 to 15 kOe.

[0017] The magnetic material target according to an embodiment of the present invention may contain Mo in a single form, in an alloy form, or in an oxide form. Examples of the oxide of Mo include MoO3. Here, in the magnetic material target according to an embodiment of the present invention, how to determine that Mo is contained in the form of an oxide will be described below. First, a magnetic material target is cut, and its cross-section is mirror-polished to obtain a sample for microstructure observation. More specifically, by this mirror polishing, the cross-section of the magnetic material target is polished in order using polishing papers with numbers ranging from P80 to P2000, and finally, buff polishing is performed using aluminum oxide abrasive grains with a particle size of 0.3 μm, thereby obtaining a sample for microstructure observation having a polished surface on the cross-section. Also, at this time, the aluminum oxide and granular polishing debris adhering to the polished surface are surely removed by washing. Subsequently, for the sputter surface of the sample after mirror polishing, WDX mapping analysis (Wave Length-Dispersive X-ray Mapping Spectroscopy) in a 50 μm × 50 μm field of view by FE-EPMA (Field Emission-Electron Probe Micro Analysis: Field Emission Type Electron Beam Microanalyzer) is performed to conduct elemental mapping. The WDX mapping analysis in a 50 μm × 50 μm field of view by FE-EPMA can be implemented by performing a stage scan under the conditions of an acceleration voltage of 15.0 kV and an irradiation current of 2.0×10 -8 A. If the parts with high detection intensities of Mo and O coincide, it is considered that most of the Mo exists in the sintered body as an oxide. Therefore, for Mo where the part with a high detection intensity coincides with O, it is determined that it is contained in the form of a Mo oxide. Also, in order to further improve the magnetic properties, the oxide may further contain one or more oxides of elements selected from Al, Si, Ba, Be, Ca, Ce, Cr, Co, Dy, Er, Eu, Ga, Ho, Li, Mg, Mn, Nb, Nd, Pr, Sc, Sm, Sr, Ta, Tb, Ti, V, Y, Zn, Zr

[0018] The remainder of the magnetic material target according to the embodiment of the present invention may or may not contain impurities. Examples of such impurities include metallic elements such as Fe, Ni, Cu, Zr, Al, W, V, Zn, and Ta, as well as elemental or compound elements such as C or N from gaseous components in the atmosphere, such as carbon dioxide and nitrogen. The impurity content in the remainder of the magnetic material target according to the embodiment of the present invention may be 0.5 mol% or less, or 0.15 mol% or less. Furthermore, impurities can be analyzed by taking an analytical sample from the magnetic material target and using methods such as infrared absorption spectroscopy, ICP emission spectrometry, and GDMS (glow discharge mass spectrometry). The amount and shape of the analytical sample will vary depending on the analytical method adopted, and the optimal amount and shape for each method can be selected.

[0019] <Magnetic material target assembly> The magnetic material target according to the embodiment of the present invention may be joined with a backing plate as needed to form a magnetic material target assembly. This magnetic material target assembly can be mounted on a sputtering apparatus for use. Indium or indium tin can be used as the brazing material. Alternatively, the magnetic material target according to the embodiment of the present invention may be mounted directly on the sputtering apparatus without using a backing plate. The material of the backing plate is not particularly limited and can be Cu, Ti, Mo, or alloys containing at least one of these (for example, Cu-Ni-Si alloy (e.g., C18000), CuZn alloy, CuCr alloy). The material of the backing plate preferably has high thermal conductivity, and from this viewpoint, Cu is preferred.

[0020] <Method for manufacturing magnetic material targets> The following describes in detail a method for manufacturing a magnetic material target according to an embodiment of the present invention. A magnetic material target according to an embodiment of the present invention can be manufactured by powder sintering. First, powders of each metal element are prepared. Alternatively, alloy powders of these metals (e.g., Co-Pt powder) may be used instead of individual metal element powders. In particular, it is preferable to use Co powder, Pt powder, B2O3 powder, MoO3 powder, CoO powder, etc. For the 50% cumulative volume particle size D50 (average particle size D50) of each raw material powder, sizes of 1 to 10 μm for Co powder, 1 to 10 μm for Pt powder, 0.1 to 5 μm for B2O3 powder, 1 to 50 μm for MoO3 powder, and 1 to 50 μm for CoO powder can be used. The purity of these raw material powders is usually 2N (99% by mass) or higher, preferably 3N (99.9% by mass) or higher, and more preferably 4N (99.99% by mass) or higher. If the purity is lower than 2N, the sintered body will contain many impurities, which may result in the inability to obtain the desired physical properties (for example, generation of particles due to arcing). These raw material powders can be prepared as appropriate from the desired composition and purity of the sintered body.

[0021] These metal powders are then weighed to the desired composition and mixed using a mixing device, which also grinds them. Non-magnetic particles may also be mixed with the metal powders at this stage. A ball mill, mortar and pestle, etc., can be used as the mixing device, but it is preferable to use a powerful mixing method such as a ball mill. Furthermore, considering the problem of oxidation during mixing, it is preferable to mix in an inert gas atmosphere or under vacuum.

[0022] Here, the mixing process involves primary mixing, followed by sieving, and then secondary mixing. It is preferable to perform primary mixing for 5 to 30 hours, and secondary mixing for 5 to 30 hours.

[0023] The mixed powder obtained in this way is molded and sintered using a hot press to create a sintered body. Molding and sintering can be done not only with a hot press, but also with plasma discharge sintering or hot hydrostatic sintering. The sintering conditions can be 650 to 1400°C for 0.5 to 12 hours.

[0024] Subsequently, the sintered body removed from the hot press is subjected to HIP (Hot Isostatic Pressing). HIP is an effective method for improving the density of the sintered body. The holding temperature during HIP is 650-1100°C, the holding time is 0.5-12 hours, and the applied pressure is 100 MPa or more. Then, the sintered body obtained in this way is machined on a lathe to the desired shape to produce a magnetic material target.

[0025] <Method for forming thin films using magnetic material targets> Using a magnetic material target according to an embodiment of the present invention, thin films constituting magnetic recording media can be formed, primarily. Specifically, a sputtering apparatus is used to sputter the surface of the magnetic material target with accelerated argon ions, releasing particles (sputtered particles) from the magnetic material target. These sputtered particles are then deposited onto the surface of a substrate pre-positioned opposite, thereby forming a thin film on the substrate surface. The sputtering conditions can be appropriately set depending on the desired film thickness, composition, and other factors. [Examples]

[0026] Examples of the present invention are shown below, but these examples are provided to better understand the present invention and its advantages, and are not intended to limit the invention.

[0027] <Example 1> The magnetic material target according to Example 1 was manufactured by the following manufacturing method. Co powder, Pt powder, B2O3 powder, CoO powder, and MoO3 powder were prepared as raw material powders, each with a composition of 3N (99.9 mass%). The powders were weighed so that the composition was Co-Pt-B-Mo-O (Pt 10-20 at%, B 7-13 at%, Mo 0.2-4 at%, O 18-25 at%, Co (remainder)). The raw material powders were prepared so that the total composition was 100 at%. The 50% cumulative volume particle size D50 (average particle size D50) of the raw material powders were as follows: Co powder: 4μm, Pt powder: 3μm, B2O3 powder: 0.1~5μm, CoO powder: 1~50μm, MoO3 powder: 1~50μm Next, the weighed Co powder, Pt powder, B2O3 powder, CoO powder, and MoO3 powder were placed in a ball mill pot along with grinding media, and a 10-hour primary mixing and a 10-hour secondary mixing were performed in that order.

[0028] Next, the mixed powder removed from the ball mill pot was filled into a carbon mold and hot-pressed. The hot-pressing conditions were a vacuum atmosphere, a heating rate of 300°C / hour, a holding temperature (sintering temperature) of 850°C, and a holding time (sintering time) of 2 hours. Pressurization was maintained at 30 MPa from the start of heating until the end of holding. After the end of holding, it was allowed to cool naturally in the chamber. Subsequently, the sintered body removed from the hot-press mold was subjected to HIP processing. The HIP processing conditions were a heating rate of 300°C / hour, a holding temperature of 850°C, and a holding time of 2 hours. The gas pressure of Ar gas was gradually increased from the start of heating, and pressurization was maintained at 150 MPa during holding. After the end of holding, it was allowed to cool naturally in the furnace. In this way, a magnetic material target according to Example 1 was fabricated.

[0029] <Comparative Example 1> A magnetic material target according to Comparative Example 1 was manufactured by the following manufacturing method. As raw material powders, 3N (99.9 mass%) Co powder, Pt powder, B2O3 powder, CoO powder, and TiO2 powder were prepared, and weighed to have a composition of Co-Pt-B-Ti-O (Pt 10-20 at%, B 7-13 at%, Ti 0.2-4 at%, O 18-25 at%, Co (remainder)). The raw material powders were prepared so that the total composition was 100 at%. The 50% cumulative volume particle size D50 (average particle size D50) of the raw material powders were as follows: Co powder: 4μm, Pt powder: 3μm, B2O3 powder: 0.1~5μm, CoO powder: 1~50μm, TiO2 powder: 0.5~5μm Next, the weighed Co powder, Pt powder, B2O3 powder, CoO powder, and TiO2 powder were placed in a ball mill pot along with grinding media, and a 10-hour primary mixing and a 10-hour secondary mixing were performed in that order.

[0030] Next, the mixed powder removed from the ball mill pot was filled into a carbon mold and hot-pressed. The hot-pressing conditions were a vacuum atmosphere, a heating rate of 300°C / hour, a holding temperature (sintering temperature) of 850°C, and a holding time (sintering time) of 2 hours. Pressurization was performed at 30 MPa from the start of heating until the end of holding. After the end of holding, it was allowed to cool naturally in the chamber. Subsequently, the sintered body removed from the hot-press mold was subjected to HIP processing. The HIP processing conditions were a heating rate of 300°C / hour, a holding temperature of 850°C, and a holding time of 2 hours. The gas pressure of Ar gas was gradually increased from the start of heating, and pressurization was performed at 150 MPa during holding. After the end of holding, it was allowed to cool naturally in the furnace. In this way, a magnetic material target according to Comparative Example 1 was fabricated.

[0031] <Comparative Example 2> A magnetic material target according to Comparative Example 2 was manufactured by the following manufacturing method. As raw material powders, 3N (99.9 mass%) Co powder, Pt powder, B2O3 powder, CoO powder, and Cr2O3 powder were prepared, and weighed to have a composition of Co-Pt-B-Cr-O (Pt 10-20 at%, B 7-13 at%, Cr 0.2-4 at%, O 18-25 at%, Co (remainder)). The raw material powders were prepared so that the total composition was 100 at%. The 50% cumulative volume particle size D50 (average particle size D50) of the raw material powders were as follows: Co powder: 4μm, Pt powder: 3μm, B2O3 powder: 0.1~5μm, CoO powder: 1~50μm, Cr2O3 powder: 1~50μm Next, the weighed Co powder, Pt powder, B2O3 powder, CoO powder, and Cr2O3 powder were placed in a ball mill pot along with grinding media, and a 10-hour primary mixing and a 10-hour secondary mixing were performed in that order.

[0032] Next, the mixed powder removed from the ball mill pot was filled into a carbon mold and hot-pressed. The hot-pressing conditions were a vacuum atmosphere, a heating rate of 300°C / hour, a holding temperature (sintering temperature) of 850°C, and a holding time (sintering time) of 2 hours. Pressurization was maintained at 30 MPa from the start of heating until the end of holding. After the end of holding, it was allowed to cool naturally in the chamber. Subsequently, the sintered body removed from the hot-press mold was subjected to HIP processing. The HIP processing conditions were a heating rate of 300°C / hour, a holding temperature of 850°C, and a holding time of 2 hours. The gas pressure of Ar gas was gradually increased from the start of heating, and pressurization was maintained at 150 MPa during holding. After the end of holding, it was allowed to cool naturally in the furnace. In this way, a magnetic material target according to Comparative Example 2 was fabricated.

[0033] <Composition analysis> Chips were collected from the magnetic material targets of Example 1 and Comparative Examples 1 and 2. The composition of Co, Pt, B, Mo, Ti, and Cr was analyzed by ICP emission spectrometry (Hitachi High-Tech Corporation, model SPS5520). The value for O was quantitatively analyzed using non-dispersive infrared absorption spectroscopy (LECO Corporation, CS-444). Table 1 shows the analytical compositions of the magnetic material targets for Example 1, Comparative Examples 1 and 2.

[0034] [Table 1]

[0035] <Oxides> The oxides contained in the magnetic material target according to Example 1 were analyzed as follows. First, a sample for microstructural observation was obtained by cutting a magnetic material target and mirror-polishing its cross-section. More specifically, the cross-section of the magnetic material target was polished sequentially using abrasive cloths and papers with grits ranging from P80 to P2000, and finally, buff polishing was performed using aluminum oxide abrasive grains with a particle size of 0.3 μm to obtain a sample for microstructural observation with a polished surface on the cross-section. At this time, aluminum oxide and granular polishing debris adhering to the polished surface were thoroughly removed by washing. Subsequently, elemental mapping was performed on the sputtered surface of the mirror-polished sample by WDX mapping analysis (Wave Length-Dispersive X-ray Mapping Spectroscopy) in a 50 μm × 50 μm field of view using FE-EPMA (Field Emission-Electron Probe Micro Analysis). The WDX mapping analysis in a 50 μm × 50 μm field of view using FE-EPMA was performed with an acceleration voltage of 15.0 kV and an irradiation current of 2.0 × 10⁻¹⁰ -8 This was achieved by performing a stage scan under condition A. In this case, if the areas with high detection intensity for Mo and O coincide, it is considered that the majority of the Mo is present in the sintered body as an oxide. Therefore, the Mo whose areas with high detection intensity coincided with O was determined to be present in the form of Mo oxide. Furthermore, the determination of other Ti oxides, Co oxides, etc., was carried out in the same manner as the determination method for Mo oxides described above. As a result, Mo oxide was confirmed for the magnetic material target in Example 1, Ti oxide was confirmed for the magnetic material target in Comparative Example 1, and Cr oxide was confirmed for the magnetic material target in Comparative Example 2.

[0036] <Test Example 1: Hc (Holding Power) Evaluation Test> The Hc (coercivity) of the magnetic material targets in Example 1, Comparative Examples 1 and 2 was measured by the following method. First, Cr-Ti (6nm), Ni-W (5nm), and Ru (20nm) films were deposited on a glass substrate in that order using a magnetron sputtering apparatus (Canon Anelva Corporation C-3010). Then, the aforementioned sputtering targets were sputtered at 300W under an Ar 3.0Pa atmosphere to deposit magnetic films with a thickness of 11nm. After that, a protective film of Ru (3nm) was deposited to prevent oxidation of the magnetic films, thus forming each layer. The Hc (coercivity) of the magnetic films obtained by the above deposition operation was measured using a Kerr measuring device (perpendicular magnetic recording hard disk recording layer evaluation device) manufactured by Neoarc Corporation. The evaluation results are shown in Figure 1.

[0037] As shown in Figure 1, the magnetic material target according to Example 1 achieved its maximum Hc (coercivity) at a high temperature (substrate temperature) of 230°C, demonstrating superior values ​​compared to the conventional magnetic material targets according to Comparative Examples 1 and 2.

[0038] <Test Example 2: Dn (Magnetic Cluster Size) Evaluation Test> The magnetic material targets in Example 1, Comparative Examples 1 and 2 were measured for Dn (magnetic cluster size) by the following method. First, the saturation magnetization Ms of the magnetic film obtained by the film deposition procedure in Test Example 1 was measured using a vibrating sample type magnetometer manufactured by Tamagawa Seisakusho Co., Ltd. The measurement conditions were all set to a maximum applied magnetic field of 22 kOe. Using this saturation magnetization Ms and the Hc (coercivity) obtained with the Kerr measuring device in Test Example 1, Dn (magnetic cluster size) was calculated. The evaluation results are shown in Figure 2.

[0039] The applied magnetic field was initially adjusted to 22 kOe, then swept down to -Hc, and then swept again to 22 kOe to obtain the minor hysteresis curve. Next, dθ / dH was calculated by differentiating the major loop and the minor loop. The horizontal axis was then remapped to the effective magnetic field (Heff) converted using the following equation (1). In the following equation, H represents the applied magnetic field. Effective magnetic field (Heff) = Applied magnetic field H - Demagnetizing field Hd (1)

[0040] Regarding the value of this demagnetizing field, when plotting dθ / dH obtained from the major loop and dθ / dH obtained from the minor loop with the effective magnetic field on the horizontal axis, Hd was determined so that the graphs overlap where dθ / dH increases.

[0041] Next, the saturation magnetization Ms was measured using a sample vibration magnetometer (VSM) manufactured by Tamagawa Seisakusho Co., Ltd., and the demagnetizing coefficient Nd was determined using the following equation (2). Demagnetizing coefficient Nd = Hd / (4πMs) (2)

[0042] The magnetic cluster size Dn was determined using the obtained demagnetizing coefficient Nd and the thickness t of the magnetic film of the sample, according to equation (3) below.

number

[0043] As shown in Figure 2, the magnetic material target according to Example 1 showed a smaller Dn (magnetic cluster size) at a high temperature (substrate temperature) of 230°C compared to the magnetic material targets according to Comparative Examples 1 and 2, which are conventional products.

[0044] According to one embodiment of the present invention, a novel magnetic material target with magnetic properties can be obtained, which may contribute to the advancement of sputtering thin film formation technology used in the manufacture of magnetic recording hard disk media and the like. For this reason, one embodiment of the present invention may contribute to Goal 9 of the United Nations-led Sustainable Development Goals (SDGs), "Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation."

Claims

1. It contains one or more of Pt and B, Mo, an oxide, and the remainder is Co and selectively included impurities. The combined concentration of Co and Pt is 50 at% or more. The combined concentration of B and Mo is 10 at% or more. A magnetic material target with an O concentration of 20 at% or more.

2. The magnetic material target according to claim 1, wherein the oxide further contains one or more oxides of elements selected from Al, Si, Ba, Be, Ca, Ce, Cr, Co, Dy, Er, Eu, Ga, Ho, Li, Mg, Mn, Nb, Nd, Pr, Sc, Sm, Sr, Ta, Tb, Ti, V, Y, Zn, and Zr.

3. A magnetic material target according to claim 1 or 2, A backing plate bonded to the magnetic material target, A magnetic material target assembly equipped with the following features.

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