TWI542720B - Magnetic alloy sputtering target and recording layer for magnetic recording media - Google Patents

Description

Magnetic alloy sputtering target and recording layer for magnetic recording medium

The present invention relates to a magnetic alloy sputtering target and a recording layer for a magnetic recording medium.

With the advancement of technology, the system automatically stores data and the need to back up important files, making people rely more and more on magnetic recording media. How to improve the magnetic recording quality of magnetic recording media has become a goal of vigorous development in the recording media industry.

The magnetic recording medium is horizontal or perpendicular to the surface of the magnetic disk in accordance with the direction of magnetization, and can be classified into a horizontal magnetic recording medium and a perpendicular magnetic recording medium. In a vertical magnetic recording medium, the key to affecting the recording density is the material and characteristics of the recording layer.

The magnetic material currently used for the recording layer in a vertical magnetic recording medium is exemplified by CoPt-based alloy materials, which provide a magnetic force required for magnetization by a magnetic recording medium by a cobalt element, and The platinum element enhances the magnetocrystalline anisotropy and the coercivity (H _C ), thereby improving the storage performance of the magnetic recording medium.

However, due to the magnetic exchange coupling effect between adjacent magnetic cobalt-based crystal grains in the cobalt-platinum-based alloy material, the signal-to-noise ratio (SNR) of the magnetic recording medium is caused. Lowering, thereby degrading the read and write reliability of the magnetic recording medium.

In order to enhance the read/write reliability of the magnetic recording medium, the prior art provides a cobalt-plated-oxide (CoPt-oxide) composite material containing a non-magnetic oxide, at least one selected from the group consisting of cerium oxide (SiO). ₂ ), tantalum pentoxide (Ta ₂ O ₅ ), chromium oxide (Cr ₂ O ₃ ), titanium dioxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), magnesium oxide (MgO), two A compound of cerium oxide (ThO ₂ ), zirconium dioxide (ZrO ₂ ), cerium oxide (CeO ₂ ), or antimony trioxide (Y ₂ O ₃ ).

When the non-magnetic oxide-containing cobalt platinum-oxide composite material is applied to a recording layer of a vertical magnetic recording medium, the recording layer has a magnetic base phase and a non-magnetic oxide phase, and the magnetic base phase is the main The composition is cobalt and platinum, and the non-magnetic oxide phase is located between the two crystal grains of the magnetic base phase, so as to block the magnetic exchange coupling between the two crystal grains of the magnetic base phase, thereby improving the read and write reliability of the magnetic recording medium. degree.

However, the non-magnetic oxide phase cannot completely cover the crystal grains of the magnetic base phase, so that the magnetic exchange coupling between the two crystal grains of the magnetic base phase cannot be completely isolated, which will cause signal noise of the magnetic recording medium. The magnetic properties such as the ratio, the magnetocrystalline anisotropy constant, and the coercive force are not ideal, and the demand for a high-density magnetic recording medium cannot be achieved.

In view of the above disadvantages of the prior art, the object of the present invention is In order to improve the structure of the non-magnetic oxide, the non-magnetic oxide is used to record the magnetic exchange coupling between the crystal grains of the magnetic base phase, thereby improving the signal noise ratio, the magnetocrystalline anisotropy constant and the coercive force, thereby achieving The demand for high density magnetic recording media.

In order to achieve the foregoing object, the technical means adopted by the present invention provides a magnetic alloy sputtering target comprising: a magnetic base phase and an amorphous phase, comprising a first oxide, the first oxide The components are selected from the group consisting of MgB ₄ O ₇ , Mg ₂ B ₂ O ₅ , Mg ₃ B ₂ O _{6 ,} and combinations thereof.

After the high-temperature vacuum hot-press sintering process of the magnetic alloy sputtering target of the present invention, the amorphous phase does have good high-temperature stability, and the grain system is uniformly distributed and small, which can prevent the occurrence of arc phenomenon during sputtering, and Improve the stability of the sputtering and the yield of the product.

Preferably, the first oxide is present in an amount of from 1.5 to 8 mole percent (mol%) of the overall magnetic alloy sputtering target.

More preferably, the first oxide is present in an amount of from 3 to 6 mole percent of the overall magnetic alloy sputtering target.

Preferably, the magnetic base phase comprises at least one magnetic material selected from the group consisting of cobalt, iron and alloys thereof. More preferably, the magnetic base phase comprises at least one magnetic alloy selected from the group consisting of cobalt platinum alloy, cobalt chromium platinum alloy and iron platinum alloy.

Preferably, the magnetic alloy sputtering target further comprises a second oxide, the second oxide comprising at least one selected from the group consisting of aluminum, titanium, tantalum, chromium, gallium, magnesium and iron. a metal element in the group, and the component of the second oxide does not comprise a group selected from the group consisting of MgB ₄ O ₇ , Mg ₂ B ₂ O ₅ , Mg ₃ B ₂ O ₆ or a combination thereof.

More preferably, the second oxide comprises from 0.1 to 9 mole percent of the overall magnetic alloy sputtering target.

Even more preferably, the second oxide comprises from 0.1 to 6 mole percent of the overall magnetic alloy sputtering target.

In order to achieve the foregoing object, the technical means adopted by the present invention provides a recording layer for a magnetic recording medium, comprising: a magnetic base phase and an amorphous phase, comprising a first oxide, the first The component of the oxide is selected from the group consisting of MgB ₄ O ₇ , Mg ₂ B ₂ O ₅ , Mg ₃ B ₂ O ₆ or a combination thereof.

Since the magnetic recording layer for the magnetic recording medium of the present invention comprises an amorphous phase, the magnetic exchange coupling between the crystal grains of the magnetic base phase can be effectively blocked, thereby improving the signal noise ratio and the magnetic crystal difference of the magnetic recording medium. The directional constant and the coercive force enable the demand for high-density magnetic recording media.

Preferably, the first oxide accounts for 1.5 to 8 mole percent of the recording layer used for the magnetic recording medium as a whole. More preferably, the first oxide comprises from 3 to 6 mole percent of the overall magnetic alloy sputtering target. According to this, by adjusting the ratio of the first oxide to the recording layer for the magnetic recording medium as a whole, the magnetic exchange coupling between the crystal grains of the magnetic base phase can be reduced, and the magnetic recording medium can be used. The magnetic recording layer also contains a suitable number of crystal grains of the magnetic base phase, thereby having an optimized signal noise ratio, a magnetocrystalline anisotropy constant, and a coercive force.

Preferably, the magnetic base phase comprises cobalt or iron. More preferably, the magnetic base phase comprises at least one magnetic alloy selected from the group consisting of cobalt platinum alloy, cobalt chromium platinum alloy and iron platinum alloy.

Preferably, the recording layer for a magnetic recording medium further comprises a second oxide, the second oxide comprising at least one selected from the group consisting of aluminum, titanium, tantalum, chromium, gallium, magnesium and iron. a metal in the group, and the component of the second oxide does not comprise a group selected from the group consisting of MgB ₄ O ₇ , Mg ₂ B ₂ O ₅ , Mg ₃ B ₂ O ₆ or a combination thereof. Accordingly, by the addition of the second oxide, the magnetic exchange coupling between the crystal grains of the magnetic base phase can be reduced, and the signal noise ratio, the magnetocrystalline anisotropy constant, and the coercive force are improved.

More preferably, the second oxide accounts for 0.1 to 9 mole percent of the entire recording layer for the magnetic recording medium. Even more preferably, the second oxide comprises from 0.1 to 6 mole percent of the overall magnetic alloy sputtering target. According to this, by adjusting the ratio of the second oxide to the recording layer for the magnetic recording medium as a whole, the magnetic recording layer for the magnetic recording medium can have an optimized signal noise ratio and a magnetocrystalline anisotropy constant. And coercivity.

Preferably, the recording layer for the magnetic recording medium is formed by the magnetic alloy sputtering target through a sputtering process. Optional sputtering processes such as, but not limited to, magnetron sputtering processes, electronic plasma processes, and ion beam sputtering processes.

Accordingly, the recording layer for a magnetic recording medium has high sputter stability and yield during sputtering, and the amorphous phase thereof can effectively block the intergranularity of the magnetic base phase. The magnetic exchange coupling function enhances the signal noise ratio, the magnetocrystalline anisotropy constant and the coercive force of the magnetic recording medium to meet the demand of high-density magnetic recording media.

10‧‧‧Amorphous phase

10A‧‧‧Titanium Magnesium Oxide Phase

20‧‧‧ grain

20A‧‧‧ grain

1 is a microstructured metallographic diagram of a magnetic alloy sputtering target of Example 1.

2 is a X-ray diffraction spectrum of the magnetic alloy sputtering target of Example 1.

3 is a microstructured metallographic diagram of a magnetic alloy sputtering target of Example 2.

4 is a X-ray diffraction spectrum of the magnetic alloy sputtering target of Example 2.

5A is a transmission electron microscope image of a magnetic recording layer obtained by sputtering of a magnetic alloy sputtering target of Example 2. FIG.

Fig. 5B is a partial enlarged view of Fig. 5A.

6 is a microstructured metallographic diagram of a magnetic alloy sputtering target of Example 3.

7 is a X-ray diffraction spectrum of a magnetic alloy sputtering target of Example 3.

8 is a microstructured metallographic diagram of a magnetic alloy sputtering target of Example 4.

Figure 9 is a X-ray diffraction spectrum of the magnetic alloy sputtering target of Example 4.

Figure 10 is a microstructured metallographic diagram of a magnetic alloy sputtering target of Example 5.

Figure 11 is a X-ray diffraction spectrum of the magnetic alloy sputtering target of Example 5.

Figure 12 is a microstructured metallographic diagram of a magnetic alloy sputtering target of Example 6.

Figure 13 is a X-ray diffraction spectrum of the magnetic alloy sputtering target of Example 6.

Figure 14 is a microstructured metallographic diagram of the magnetic alloy sputtering target of Example 7.

Figure 15 is a X-ray diffraction spectrum of the magnetic alloy sputtering target of Example 7.

Figure 16 is a microstructured metallographic diagram of a magnetic alloy sputtering target of Example 8.

17 is an X-ray diffraction spectrum of a magnetic alloy sputtering target of Example 8. Figure.

18 is a microstructure metallographic diagram of a magnetic alloy sputtering target of Comparative Example 1.

19 is an X-ray diffraction spectrum of a magnetic alloy sputtering target of Comparative Example 1.

20 is a microstructure metallographic diagram of a magnetic alloy sputtering target of Comparative Example 2.

21 is an X-ray diffraction spectrum of a magnetic alloy sputtering target of Comparative Example 2.

Fig. 22A is a transmission electron microscope image of a magnetic recording layer obtained by sputtering of a magnetic alloy sputtering target of Comparative Example 2.

Figure 22B is a partial enlarged view of Figure 22A.

In the following, embodiments of the present invention will be described in detail by the following specific embodiments, and those skilled in the art can readily understand the advantages and functions of the present invention, and without departing from the invention. Various modifications and changes are made in the spirit of the invention to practice or apply the invention.

Example 1

After a magnetic substance is uniformly mixed with a first oxide at a molar ratio of 92:8 and ball-milled, hydrogen reduction is carried out for 2 hours at a temperature of 650 ° C and a pressure of 760 bar; then, the The magnetic material after mixing, ball milling and hydrogen reduction was ground in a high speed grinder for 2 hours, uniformly filled in a graphite mold, and subjected to a hydraulic press at a pressure of about 300 psi. Preformed to form an initial embryo. The priming and the graphite mold are placed together in a hot press furnace for sintering, at a hot pressing temperature of about 1100 ° C and a pressure of 500 bar (bar). After the hot pressing for 3 hours, the magnetic alloy sputtering target of the present example was obtained.

In the present embodiment, cobalt (Co) powder was used as the magnetic substance, and Mg ₂ B ₂ O ₅ powder was used as the first oxide.

The composition of the magnetic alloy sputtering target of the present embodiment was analyzed by an inductively coupled plasma spectrometer (ICP), brand: Perkin Elmer, model: 5300DV. The content of magnesium element was 59 ppm, and the content of boron element was obtained. At 26.5 ppm, it was found that the content of the magnesium element was 5.9 weight percent (wt%) based on the entire magnetic alloy sputtering target of the present embodiment, and the content of the boron element was 2.65 weight percent (wt%).

Referring to FIG. 1, the magnetic alloy sputtering of this embodiment is analyzed by scanning electron microscopy (SEM, brand: Hitachi, model: 3400N, acceleration voltage: 15 kV, working distance: 3 cm). The metallographic microstructure of the target can be observed that the magnetic alloy sputtering target of the present embodiment mainly contains a white phase and a black phase, and is shown in Table 1, via an Energy Dispersive Spectrometer (EDS). As a result, it was confirmed that the white phase is a magnetic base phase composed of cobalt atoms, and the black phase is a first oxide phase composed of Mg ₂ B ₂ O ₅ .

Among them, it can be observed from Fig. 1 that no phenomenon of solid solution of magnesium atoms or boron atoms is observed in the magnetic base phase, and that no solid solution of cobalt atoms is observed in the first oxide phase; As shown in Table 1, by the EDS analysis, no magnesium atom or boron atom was detected in the magnetic base phase, and no signal of the cobalt atom was detected in the first oxide phase, confirming the magnetic alloy sputtering of the present embodiment. Target system contains first oxidation with good stability And the first oxide does not form a solid solution with the magnetic base phase.

Furthermore, it can be observed from FIG. 1 that the first oxide phase of the magnetic alloy sputtering target has the characteristics of uniform distribution and smallness, so the magnetic alloy sputtering target system can prevent the arc phenomenon during sputtering. Produced to improve the stability of the sputtering and the yield of the sputtered recording layer.

2 is a magnetic alloy sputtering target of the present embodiment, which is subjected to X-ray diffractometer (XRD), brand: Rigaku, model: Ultima IV, and Kα ray scanning condition using Cu is 6 per minute. The speed of the degree is scanned from 2θ=20 degrees to 2θ=80 degrees.) The obtained X-ray diffraction spectrum is analyzed, and the X-ray diffraction spectrum of this embodiment is combined with the international powder diffraction standard (joint committee of powder diffraction standard ( The comparison of the diffraction diffraction file (PDF) of JCPDS shows that the characteristic peaks of the X-ray diffraction spectrum of this embodiment coincide with the diffraction data files 05-0727 and 15-0806, due to the numbering 05-0727 and 15-0806 are diffraction data of crystals composed of cobalt atoms, and the X-ray diffraction spectrum of the present embodiment does not compare the characteristic peaks of crystals composed of Mg ₂ B ₂ O ₅ . Further, it was confirmed by the SEM and EDS analysis results that the magnetic alloy sputtering target of the present embodiment contains a magnetic base phase composed of cobalt atoms and a first oxide phase composed of Mg ₂ B ₂ O ₅ (please Referring to FIG. 1 and Table 1); it can be seen that after sintering (sinter), the magnetic combination of this embodiment The Mg ₂ B ₂ O ₅ contained in the gold sputtering target has an amorphous structure, and the first oxide phase is an amorphous phase. The magnetic alloy sputtering target of the present embodiment is Mg ₂ B _{2 .} The amorphous phase composed of O ₅ and the magnetic base phase composed of Co are composed.

After the sintering, the magnetic alloy sputtering target of the present embodiment is composed of an amorphous phase composed of Mg ₂ B ₂ O ₅ and a magnetic phase composed of Co. Therefore, the magnetic alloy sputtering target of the embodiment The magnetic recording layer formed by sputtering also forms an amorphous phase composed of Mg ₂ B ₂ O ₅ , which has a high wetting property, which is favorable for coating the crystal grains of the magnetic base phase, thereby effectively blocking the magnetic base. The magnetic exchange coupling between the phases.

Example 2

This embodiment is substantially the same as Example 1, except that in this embodiment, the molar ratio of the magnetic substance to the first oxide is 94:6.

The composition of the magnetic alloy sputtering target of the present embodiment was analyzed by ICP, and it was found that the content of the magnesium element was 4.6 wt% and the content of the boron element was 2.0 wt% based on the entire magnetic alloy sputtering target of the present example. .

Referring to FIG. 3, the metallographic microstructure of the magnetic alloy sputtering target prepared by the embodiment can be observed that the magnetic alloy sputtering target of the embodiment mainly contains a white phase and a black phase, and Referring to Table 2, it was confirmed by EDS analysis that the white phase was a magnetic base phase composed of cobalt atoms, and the black phase was a first oxide phase composed of Mg ₂ B ₂ O ₅ .

Among them, it can be observed from Figure 3 that the magnetic base phase is not The phenomenon of solid solution of magnesium atoms or boron atoms is also observed. No phenomenon of solid solution of cobalt atoms is observed in the first oxide phase; as shown in Table 2, the magnetic phase is not detected by EDS analysis. a signal to a magnesium atom or a boron atom and no cobalt atom detected in the first oxide phase, and it is confirmed that the magnetic alloy sputtering target of the present embodiment contains the first oxide having good stability, and the first The oxide does not form a solid solution with the magnetic base.

Furthermore, it can be observed from FIG. 3 that the first oxide phase of the magnetic alloy sputtering target has the characteristics of uniform distribution and fineness, so the magnetic alloy sputtering target system can prevent the arc phenomenon during sputtering. Produced to improve the stability of the sputtering and the yield of the sputtered recording layer.

4 is a magnetic alloy sputtering target of the present embodiment, and the X-ray diffraction spectrum obtained by XRD analysis is used to compare the X-ray diffraction spectrum of the present embodiment with the PDF of JCPDS, and the X of the embodiment is shown. The characteristic peaks of the light diffraction spectrum are matched with the characteristic peaks in PDF Nos. 05-0727 and 15-0806. Since the numbers 05-0727 and 15-0806 are the diffraction data of the crystals composed of cobalt atoms, this embodiment The characteristic peaks of the crystals composed of Mg ₂ B ₂ O ₅ were not aligned in the X-ray diffraction spectrum, and it was confirmed by the aforementioned SEM and EDS analysis results that the magnetic alloy sputtering target of the present embodiment contained a magnetic base phase composed of a cobalt atom and a first oxide phase composed of Mg ₂ B ₂ O ₅ (please refer to FIG. 3 and Table 2 together); it can be seen that after sintering, the magnetic alloy of the present embodiment is splashed. The Mg ₂ B ₂ O ₅ contained in the plating target has an amorphous structure, and the first oxide phase is an amorphous phase. The magnetic alloy sputtering target of the present embodiment is Mg ₂ B ₂ O _{5 .} The amorphous phase is composed of a magnetic phase composed of cobalt atoms.

Therefore, the magnetic recording layer formed by sputtering of the magnetic alloy sputtering target of the present embodiment also forms an amorphous phase composed of Mg ₂ B ₂ O ₅ , which has high wettability and is easy to coat the magnetic base phase. The crystal grains can effectively block the magnetic exchange coupling between the crystal grains of the magnetic base phase.

Referring to FIGS. 5A and 5B, the magnetic recording layer prepared by sputtering of the magnetic alloy sputtering target of the present embodiment is subjected to transmission electron microscopy (TEM) analysis. It can be seen that the amorphous phase 10 composed of Mg ₂ B ₂ O ₅ is located between two adjacent crystal grains 20 of the magnetic base phase, that is, on the grain boundary between the adjacent two crystal grains 20, and is composed of crystal grains. The outline of the particles 20 is quite obvious. It can be seen that the amorphous phase 10 completely covers the crystal grains 20 of the magnetic base phase, and it is confirmed that the amorphous phase composed of Mg ₂ B ₂ O ₅ can effectively block the crystal grains of the magnetic base phase. Magnetic exchange coupling between.

Example 3

This embodiment is substantially the same as Embodiment 1, but in this embodiment, the molar ratio of the magnetic substance to the first oxide is 98.5:1.5.

The composition of the magnetic alloy sputtering target of the present embodiment was analyzed by ICP, and it was found that the content of the magnesium element was 1.2 wt% and the content of the boron element was 0.54 wt% based on the entire magnetic alloy sputtering target of the present example. .

Referring to FIG. 6 , the metallographic microstructure of the magnetic alloy sputtering target prepared by the embodiment can be observed that the magnetic alloy sputtering target of the embodiment mainly contains a white phase and a black phase, and Referring to Table 3, it was confirmed by EDS analysis that the white phase is a magnetic base phase composed of cobalt atoms, and the black phase is a first oxide phase composed of Mg ₂ B ₂ O ₅ .

Among them, it can be observed from Fig. 6 that no phenomenon of solid solution of magnesium atoms or boron atoms is observed in the magnetic base phase, and that no solid solution of cobalt atoms is observed in the first oxide phase; As shown in Table 3, by the EDS analysis, no magnesium atom or boron atom was detected in the magnetic base phase, and no signal of the cobalt atom was detected in the first oxide phase, confirming the magnetic alloy sputtering of the present embodiment. The target contains a first oxide having good stability, and the first oxide does not form a solid solution with the magnetic base.

Furthermore, it can be observed from FIG. 6 that the first oxide phase of the magnetic alloy sputtering target has the characteristics of uniform distribution and smallness, so the magnetic alloy sputtering target system can prevent the arc phenomenon during sputtering. Produced to improve the stability of the sputtering and the yield of the sputtered recording layer.

7 is a magnetic alloy sputtering target of the present embodiment, and the X-ray diffraction spectrum obtained by XRD analysis is used to compare the X-ray diffraction spectrum of the present embodiment with the PDF of JCPDS, and the X of the embodiment is shown. The characteristic peaks of the light diffraction spectrum are matched with the characteristic peaks in PDF Nos. 05-0727 and 15-0806. Since the numbers 05-0727 and 15-0806 are the diffraction data of the crystals composed of cobalt atoms, this embodiment The characteristic peaks of the crystals composed of Mg ₂ B ₂ O ₅ were not aligned in the X-ray diffraction spectrum, and it was confirmed by the aforementioned SEM and EDS analysis results that the magnetic alloy sputtering target of the present embodiment contained a magnetic base phase composed of a cobalt atom and a first oxide phase composed of Mg ₂ B ₂ O ₅ (please refer to FIG. 6 and Table 3 together); it can be seen that after sintering (sinter), the present embodiment The Mg ₂ B ₂ O ₅ contained in the magnetic alloy sputtering target has an amorphous structure, and the first oxide phase is an amorphous phase. The magnetic alloy sputtering target of the present embodiment is Mg ₂ B. An amorphous phase composed of ₂ O ₅ and a magnetic base phase composed of cobalt atoms.

Therefore, the magnetic recording layer formed by sputtering of the magnetic alloy sputtering target of the present embodiment also forms an amorphous phase composed of Mg ₂ B ₂ O ₅ , which has high wettability and is easy to coat the magnetic base phase. The crystal grains can effectively block the magnetic exchange coupling between the crystal grains of the magnetic base phase.

Example 4

The difference between this embodiment and the embodiment 1 is that this embodiment uses cobalt powder as a magnetic substance, and uses Mg ₃ B ₂ O ₆ powder as the first oxide, and the cobalt powder and the Mg ₃ B ₂ O ₆ powder The molar ratio of 95.5:4.5 is uniformly mixed, and the magnetic substance and the first oxide which are mixed with each other are subjected to ball milling, hydrogen reduction and preforming, and are subjected to a hot pressing temperature of about 1100 ° C and a pressure of 500 bar (bar). After continuous hot pressing for 2 hours, the magnetic alloy sputtering target of this example was obtained, and in this example, cobalt powder was used as the magnetic substance, and Mg ₃ B ₂ O ₆ powder was used as the first oxide.

The composition of the magnetic alloy sputtering target of the present embodiment was analyzed by ICP, and it was found that the content of the magnesium element was 5.06 wt% and the content of the boron element was 1.5 wt% based on the entire magnetic alloy sputtering target of the present example. .

Referring to FIG. 8 , the metallographic microstructure of the magnetic alloy sputtering target prepared by the embodiment can be observed that the magnetic alloy sputtering target of the embodiment mainly contains a white phase and a black phase, and Referring to Table 4, it was confirmed by EDS analysis that the white phase is a magnetic base phase composed of cobalt atoms, and the black phase is a first oxide phase composed of Mg ₃ B ₂ O ₆ .

Among them, it can be observed from Fig. 8 that no phenomenon of solid solution of magnesium atoms or boron atoms is observed in the magnetic base phase, and that no solid solution of cobalt atoms is observed in the first oxide phase; As shown in Table 4, by the EDS analysis, no magnesium atom or boron atom was detected in the magnetic base phase, and no signal of the cobalt atom was detected in the first oxide phase, confirming the magnetic alloy sputtering of the present embodiment. The target contains a first oxide having good stability, and the first oxide does not form a solid solution with the magnetic base.

Furthermore, the magnetic alloy sputtering target can be observed from FIG. The first oxide phase has the characteristics of uniform distribution and small size, so the magnetic alloy sputtering target system can prevent the occurrence of arcing during sputtering, thereby improving the stability of sputtering and sputtering thereof. Record layer yield.

9 is a magnetic alloy sputtering target of the present embodiment, and the X-ray diffraction spectrum obtained by XRD analysis is used to compare the X-ray diffraction spectrum of the present embodiment with the PDF of JCPDS, and the X of the embodiment is shown. The characteristic peaks of the light diffraction spectrum are matched with the characteristic peaks in PDF Nos. 05-0727 and 15-0806. Since the numbers 05-0727 and 15-0806 are the diffraction data of the crystals composed of cobalt atoms, this embodiment The characteristic peak of the crystal composed of Mg ₃ B ₂ O ₆ was not aligned in the X-ray diffraction spectrum, and it was confirmed by the aforementioned SEM and EDS analysis results that the magnetic alloy sputtering target of the present embodiment contained a magnetic base composed of a cobalt atom and a first oxide phase composed of Mg ₃ B ₂ O ₆ (please refer to FIG. 8 and Table 4 together); it can be seen that after sintering, the magnetic alloy of the present embodiment is splashed. The Mg ₃ B ₂ O ₆ system contained in the plating target has an amorphous structure, and the first oxide phase is an amorphous phase. The magnetic alloy sputtering target of the present embodiment is Mg ₃ B ₂ O _{6 .} The amorphous phase is composed of a magnetic phase composed of cobalt atoms.

Therefore, the magnetic recording layer formed by sputtering of the magnetic alloy sputtering target of the present embodiment also forms an amorphous phase composed of Mg ₃ B ₂ O ₆ , which has high wettability and is easy to coat the magnetic base phase. The crystal grains can effectively block the magnetic exchange coupling between the crystal grains of the magnetic base phase.

Example 5

The difference between this embodiment and the embodiment 1 is that in the present embodiment, MgB ₄ O ₇ powder is used as the first oxide, and the molar ratio of the cobalt powder to the MgB ₄ O ₇ powder is 96:4, which is mixed with each other. After the cobalt powder and the MgB ₄ O ₇ powder are ball-milled, hydrogen-reduced and preformed, the magnetic properties of the embodiment are obtained by continuously pressing at a hot pressing temperature of about 950 ° C and a pressure of 500 bar (bar) for 2 hours. Alloy sputtering target.

The composition of the magnetic alloy sputtering target of the present embodiment was analyzed by ICP, and it was found that the content of the magnesium element was 1.5 wt% and the content of the boron element was 2.7 wt% based on the entire magnetic alloy sputtering target of the present example. .

Referring to FIG. 10, the metallographic microstructure of the magnetic alloy sputtering target prepared by the embodiment can be observed that the magnetic alloy sputtering target of the embodiment mainly contains a white phase and a black phase, and Referring to Table 5, it was confirmed by EDS analysis that the white phase is a magnetic base phase composed of cobalt atoms, and the black phase is a first oxide phase composed of MgB ₄ O ₇ .

Among them, it can be observed from Fig. 10 that no phenomenon of solid solution of magnesium atoms or boron atoms is observed in the magnetic base phase, and that no solid solution of cobalt atoms is observed in the first oxide phase; As shown in Table 5, by the EDS analysis, no magnesium atom or boron atom was detected in the magnetic base phase, and no signal of the cobalt atom was detected in the first oxide phase, confirming the magnetic alloy sputtering of the present embodiment. Target system contains first oxidation with good stability And the first oxide does not form a solid solution with the magnetic base phase.

Furthermore, it can be observed from FIG. 10 that the first oxide phase of the magnetic alloy sputtering target has the characteristics of uniform distribution and smallness, so the magnetic alloy sputtering target system can prevent the arc phenomenon during sputtering. Produced to improve the stability of the sputtering and the yield of the sputtered recording layer.

11 is a magnetic alloy sputtering target of the present embodiment, and the X-ray diffraction spectrum obtained by XRD analysis is used to compare the X-ray diffraction spectrum of the present embodiment with the PDF of JCPDS, and the X of the present embodiment is shown. The characteristic peaks of the light diffraction spectrum are matched with the characteristic peaks in PDF Nos. 05-0727 and 15-0806. Since the numbers 05-0727 and 15-0806 are the diffraction data of the crystals composed of cobalt atoms, this embodiment The characteristic peaks of the crystals composed of Mg ₂ B ₂ O ₅ were not aligned in the X-ray diffraction spectrum, and it was confirmed by the aforementioned SEM and EDS analysis results that the magnetic alloy sputtering target of the present embodiment contained a magnetic base phase composed of a cobalt atom and a first oxide phase composed of MgB ₄ O ₇ (please refer to FIG. 10 and Table 5 together); thus, it can be seen that after sintering, the magnetic alloy sputtering target of the present embodiment The MgB ₄ O ₇ system contained in the material has an amorphous structure, and the first oxide phase is an amorphous phase. The magnetic alloy sputtering target of the present embodiment is an amorphous phase composed of MgB ₄ O ₇ and It consists of a magnetic base composed of cobalt atoms.

After the sintering, the magnetic alloy sputtering target of the present embodiment is composed of an amorphous phase composed of MgB ₄ O ₇ and a magnetic phase composed of Co. Therefore, the magnetic alloy sputtering target of the present embodiment is splashed. The magnetic recording layer formed by plating also forms an amorphous phase composed of MgB ₄ O ₇ , which has high wettability and can easily coat the crystal grains of the magnetic base phase, thereby effectively blocking the magnetic properties between the crystal grains of the magnetic base phase. Exchange coupling.

Example 6

The difference between this embodiment and the embodiment 1 is that in the embodiment, an iron-platinum alloy prepared by using iron (Fe) powder and platinum (Pt) powder in a molar ratio of 1:1 is used as a magnetic substance, iron-cobalt alloy. The molar ratio of Mg ₂ B ₂ O ₅ powder is 93.6:6.4, and the mixed iron platinum powder and Mg ₂ B ₂ O ₅ powder are subjected to ball milling, hydrogen reduction and preforming, and are subjected to a hot pressing temperature of about 1100 ° C. Under the pressure of 500 bar, the magnetic alloy sputtering target of the present embodiment was obtained by continuously hot pressing for 2 hours.

The composition of the magnetic alloy sputtering target of the present embodiment was analyzed by ICP, and it was found that the content of the magnesium element was 2.45 wt% and the content of the boron element was 1.09 wt% based on the entire magnetic alloy sputtering target of the present example. .

Referring to FIG. 12, the metallographic microstructure of the magnetic alloy sputtering target prepared in this embodiment can be observed that the magnetic alloy sputtering target of the embodiment mainly contains a white phase and a black phase, and Referring to Table 6, it was confirmed by EDS analysis that the white phase was a magnetic base phase composed of an iron atom and a platinum atom, and the black phase was a first oxide phase composed of Mg ₂ B ₂ O ₅ .

Among them, it can be observed from Fig. 12 that no magnesium atom or boron atom is dissolved in the magnetic base phase, and it is also observed that no iron atom or platinum atom is dissolved in the first oxide phase. Phenomenon; as shown in Table 6, through the EDS analysis, no magnesium atom or boron atom was detected in the magnetic base phase, and no signal of iron atom or platinum atom was detected in the first oxide phase, confirming the implementation. For example, the magnetic alloy sputtering target contains a first oxide having good stability, and the first oxide does not form a solid solution with the magnetic base.

Furthermore, it can be observed from FIG. 12 that the first oxide phase of the magnetic alloy sputtering target has the characteristics of uniform distribution and smallness, so the magnetic alloy sputtering target system can prevent the arc phenomenon during sputtering. Produced to improve the stability of the sputtering and the yield of the sputtered recording layer.

13 is a magnetic alloy sputtering target of the present embodiment, and the X-ray diffraction spectrum obtained by XRD analysis is used to compare the X-ray diffraction spectrum of the present embodiment with the PDF of JCPDS, and the X of the present embodiment is shown. The characteristic peak of the light diffraction spectrum is matched with the characteristic peaks of PDF No. 65-9121 and the diffraction peak of the crystal of the iron-platinum alloy, the number 65-9121 is the diffraction data of the X-ray diffraction spectrum of this embodiment. The characteristic peaks of the crystal composed of Mg ₂ B ₂ O _{5 were} not compared, and it was confirmed by the above SEM and EDS analysis results that the magnetic alloy sputtering target of the present embodiment contained magnetic properties composed of iron atoms and platinum atoms. a base phase and a first oxide phase composed of Mg ₂ B ₂ O ₅ (please refer to FIG. 12 and Table 6 together); it can be seen that after sintering, the magnetic alloy sputtering target of the present embodiment contains The Mg ₂ B ₂ O ₅ is an amorphous structure, and the first oxide phase is an amorphous phase, and the magnetic alloy sputtering target of the present embodiment is an amorphous phase composed of Mg ₂ B ₂ O ₅ . And composed of a magnetic base composed of iron and platinum atoms.

Therefore, the magnetic recording layer formed by sputtering of the magnetic alloy sputtering target of the present embodiment also forms an amorphous phase composed of Mg ₂ B ₂ O ₅ , which has high wettability and is easy to coat the magnetic base phase. The crystal grains can effectively block the magnetic exchange coupling between the crystal grains of the magnetic base phase.

Example 7

The difference between this embodiment and the first embodiment is that in the present embodiment, cobalt powder, chromium powder, and platinum powder are used as a magnetic substance in a molar ratio of 75:4:21, and Mg ₂ B ₂ O is used. ₅ powder as the first oxide, and the molar ratio of the cobalt chromium platinum alloy to the Mg ₂ B ₂ O ₅ powder is 94:6.

The composition of the magnetic alloy sputtering target of the present embodiment was analyzed by ICP, and it was found that the content of the magnesium element was 3.2 wt% and the content of the boron element was 1.4 wt% based on the entire magnetic alloy sputtering target of the present example. .

Referring to FIG. 14 , the metallographic microstructure of the magnetic alloy sputtering target prepared by the embodiment can be observed that the magnetic alloy sputtering target of the embodiment mainly contains a white phase and a black phase, and Referring to Table 7, it was confirmed by EDS analysis that the white phase was a magnetic base phase composed of cobalt, chromium, and platinum atoms, and the black phase was a first oxide phase composed of Mg ₂ B ₂ O ₅ .

Among them, it can be observed from Fig. 14 that no magnesium atom or boron atom is dissolved in the magnetic base phase, and it is also observed that cobalt, chromium, and platinum atoms are not dissolved in the first oxide phase. The phenomenon; as shown in Table 7, by the EDS analysis, no magnesium or boron atoms were detected in the magnetic phase, and no signals of cobalt, chromium or platinum atoms were detected in the first oxide phase, confirming The magnetic alloy sputtering target of the present embodiment contains good a stable first oxide, and the first oxide does not form a solid solution with the magnetic base.

Furthermore, it can be observed from FIG. 14 that the first oxide phase of the magnetic alloy sputtering target has the characteristics of uniform distribution and smallness, so the magnetic alloy sputtering target system can prevent the arc phenomenon during sputtering. Produced to improve the stability of the sputtering and the yield of the sputtered recording layer.

Figure 15 is a magnetic alloy sputtering target of the present embodiment. The X-ray diffraction spectrum obtained by XRD analysis is used to compare the X-ray diffraction spectrum of the present embodiment with the PDF of the JCPDS to display the X-ray of the present embodiment. The characteristic peaks of the diffraction spectrum are matched with the characteristic peaks in PDF Nos. 15-0806, 88-2325, and 88-2323. Since the numbers 15-0806 and 88-2325 are diffraction data of crystals composed of cobalt atoms, No. 88 -2323 is a diffraction data of a crystal of a crystal composed of a chromium atom, and the X-ray diffraction spectrum of the present embodiment does not compare the characteristic peak of the crystal composed of Mg ₂ B ₂ O ₅ (PDF No. 73-2107) And, as confirmed by the foregoing SEM and EDS analysis results, the magnetic alloy sputtering target of the present embodiment contains a magnetic base composed of cobalt, chromium, and platinum atoms and a first composed of Mg ₂ B ₂ O ₅ . The oxide phase (please refer to FIG. 14 and Table 7 together); it is understood that the Mg ₂ B ₂ O ₅ contained in the magnetic alloy sputtering target of the present embodiment has an amorphous structure after sintering. The first oxide phase is an amorphous phase, and the magnetic alloy sputtering target of the present embodiment is amorphous formed of Mg ₂ B ₂ O ₅ . The phase consists of a magnetic base composed of cobalt, chromium and platinum atoms.

After the sintering, the magnetic alloy sputtering target of the present embodiment is composed of an amorphous phase composed of Mg ₂ B ₂ O ₅ and a magnetic base phase composed of cobalt, chromium, and platinum atoms. Therefore, the magnetic property of the embodiment The magnetic recording layer formed by sputtering of the alloy sputtering target also forms an amorphous phase composed of Mg ₂ B ₂ O ₅ , which has high wettability and can easily coat the crystal grains of the magnetic base phase, thereby effectively blocking Magnetic exchange coupling between grains of a magnetic base phase.

Example 8

After a magnetic substance, a first oxide and a second oxide are uniformly mixed and ball-milled, the mixture is reduced with hydrogen at a temperature of 650 ° C and a pressure of 760 bar; then, the mixture is mixed. After the ball mill and the hydrogen-reduced magnetic substance, the first oxide and the second oxide are ground in a high-speed mill for 2 hours, they are uniformly filled in a graphite mold, and then preformed by a hydraulic press having a pressure of about 300 psi. To form an initial embryo. The priming and the graphite mold are placed in a hot press furnace for sintering, and the hot pressing is continued for 2 hours at a hot pressing temperature of about 950 ° C and a pressure of 500 bar. After the sintering is completed, the magnetic alloy of the embodiment is obtained. Sputter target.

In this embodiment, a cobalt chrome platinum alloy is used as the magnetic material, and the cobalt chrome platinum alloy is made of cobalt powder, chromium powder and platinum powder at a molar ratio of 72:12:16, the first of which is The oxide system uses the Mg ₂ B ₂ O ₅ powder as in Example 1, and the second oxide contains chromium trioxide (Cr ₂ O ₃ ) powder and titanium dioxide (TiO ₂ ) powder, cobalt chromium platinum alloy, Mg _{2 .} The B ₂ O ₅ powder, the chromium oxide (Cr ₂ O ₃ ) powder, and the titanium dioxide (TiO ₂ ) powder were uniformly mixed at a molar ratio of 80:6:5:9.

The composition of the magnetic alloy sputtering target of the present embodiment was analyzed by ICP, and it was found that the content of magnesium was 3.5 wt%, the content of boron was 1.6 wt%, and chromium based on the entire target of the magnetic alloy sputtering target of the present example. The content was 6.3 wt%, and the content of titanium was 5.2 wt%.

Referring to FIG. 16, the metallographic microstructure of the magnetic alloy sputtering target prepared by the embodiment can be observed that the magnetic alloy sputtering target of the embodiment mainly contains a white phase and a black phase, and Referring to Table 8, the white phase is a magnetic base composed of cobalt, chromium and platinum atoms, and the black phase contains a first oxide phase composed of Mg ₂ B ₂ O ₅ and contains Cr ₂ O _{3 .} And a second oxide phase of TiO ₂ .

Among them, it can be observed from FIG. 16 that the magnesium atom or the boron atom is not dissolved in the magnetic phase (white phase), and it is confirmed that the magnetic alloy sputtering target of the present embodiment has good stability. The first oxide.

Furthermore, it can be observed from FIG. 16 that the first oxide phase and the second oxide phase of the magnetic alloy sputtering target have the characteristics of uniform distribution and smallness, so the magnetic alloy sputtering target system can prevent the magnetic alloy. The occurrence of arcing during sputtering increases the stability of the sputtering and the yield of the sputtered recording layer.

17 is a X-ray diffraction spectrum obtained by XRD analysis of the magnetic alloy sputtering target of the present embodiment, and the X-ray diffraction spectrum of the present embodiment and the X-ray diffraction spectrum of Example 7 (see FIG. After the comparison, it was found that the X-ray diffraction spectrum of the present embodiment contains the same characteristic peak as that of Example 7 as compared with Example 7, and further contains 2θ of 21°, 26.2°, and 30°. Characteristic peaks of 35.5°~36°, 43°, 57° and 63°. Further, the X-ray diffraction spectrum of the present embodiment is compared with the PDF of the JCPDS, and the additional characteristic peaks of the X-ray diffraction spectrum of the present embodiment are shown in PDF numbers 06-0532, 65-2868, and 53-0619. The characteristic peaks are matched. Since the numbers 06-0532, 65-2868, and 53-0619 are respectively crystals of chromium oxide (CrO), crystals of platinum atoms, and diffraction data of crystals of titanium dioxide (TiO ₂ ), this embodiment In the X-ray diffraction spectrum of the example, the characteristic peak of the crystal composed of Mg ₂ B ₂ O ₅ is not aligned; thus, it is understood that the Mg ₂ contained in the magnetic alloy sputtering target of the present embodiment after sintering is obtained. The B ₂ O ₅ system is an amorphous structure, and the chromium oxide (Cr ₂ O ₃ ) and titanium dioxide (TiO ₂ ) are crystalline structures. The magnetic alloy sputtering target of the present embodiment is Mg ₂ B _{2 .} An amorphous phase composed of O ₅ , a crystal phase containing chromium oxide (Cr ₂ O ₃ ) and titanium oxide (TiO ₂ ); and a magnetic base phase composed of cobalt, chromium and platinum atoms.

Since the sintered magnetic alloy sputtering target of the present embodiment is an amorphous phase composed of Mg ₂ B ₂ O ₅ , a magnetic base phase composed of cobalt, chromium, and platinum atoms; and containing chromium oxide (Cr) ₂ O ₃ ) and an oxide crystal phase of titanium dioxide (TiO ₂ ). Therefore, the magnetic recording layer formed by sputtering of the magnetic alloy sputtering target of the present embodiment is also formed of Mg ₂ B ₂ O ₅ . The amorphous phase, which has high wettability and easily coats the crystal grains of the magnetic base phase, can effectively block the magnetic exchange coupling between the crystal grains of the magnetic base phase.

Comparative example 1

The cobalt powder and the boron trioxide (B ₂ O ₃ ) powder were uniformly mixed at a molar ratio of 94:6 and ball-milled, and hydrogen reduction was carried out for 2 hours at a temperature of 650 ° C and a pressure of 760 bar. Then, after grinding for 2 hours in a high speed grinder, it was uniformly filled in a graphite mold. Then, it was preformed with a hydraulic press at a pressure of about 300 psi to form an initial embryo. The priming and the graphite mold are placed in a hot press furnace for sintering, and the hot pressing is performed at a hot pressing temperature of about 1100 ° C and a pressure of 500 bar for 2 hours. After the sintering is completed, the comparison is made. An example of a magnetic alloy sputtering target. In this comparative example, cobalt powder was used as the magnetic substance.

Referring to FIG. 18, the metallographic microstructure of the magnetic alloy sputtering target of the comparative example can be observed that the magnetic alloy sputtering target of the comparative example mainly contains a white phase and a black phase, and is shown in Table 9. It was confirmed by EDS analysis that the white phase was a magnetic base phase composed of cobalt atoms, and the black phase was a boron oxide phase composed of B ₂ O ₃ .

Among them, it can be observed from Fig. 18 that no phenomenon of solid solution of boron atoms is observed in the magnetic base phase, and it is also observed that no solid solution of cobalt atoms is observed in the boron oxide phase; as shown in Table 9 It is shown that, by EDS analysis, no boron atom is detected in the magnetic base phase, and no signal of cobalt atom is detected in the boron oxide phase, and it is confirmed that the magnetic alloy sputtering target of the comparative example does not contain magnetic properties. The base phase produces a solid solution of boron oxide.

19 is a X-ray diffraction spectrum obtained by XRD analysis of the comparative example, and the X-ray diffraction spectrum of the comparative example is compared with the PDF of JCPDS, and the characteristic peak of the X-ray diffraction spectrum of the comparative example is shown. Matching the characteristic peaks in PDF Nos. 05-0727 and 15-0806, and the numbers 05-0727 and 15-0806 are the diffraction data of the crystals composed of cobalt atoms, and the X-ray diffraction spectrum of this comparative example is unaligned give crystals consisting of B ₂ O ₃ characteristic peaks, the display of the present comparative example magnetic alloy sputter target contained in the plating B ₂ O ₃ based non-amorphous structure.

Referring to Figures 1, 3, 6, 8, 10, 12, 14, 16 and 18, after further comparing the metallographic microstructures of Comparative Example 1 and Examples 1 to 8, it is known that after the high temperature vacuum hot pressing sintering process, the comparison is made. The grain size of the boron oxide phase of Example 1 is significantly larger than the grain size of the first oxide phase of Examples 1 to 8, wherein the average grain size of Examples 1 to 8 is greater than 1 μm (um), The average grain size of Example 1 was greater than 5 microns (um). That is, the grain of the boron oxide phase of Comparative Example 1 is coarsened, indicating that the high temperature stability of the boron oxide phase of Comparative Example 1 is inferior to that of the first oxide phase of Examples 1 to 8, and Comparative Example 1 The occurrence of arc prevention was not achieved, so the sputtering stability and product yield of Comparative Example 1 were inferior.

Comparative example 2

Cobalt powder, magnesium oxide (MgO) powder and titanium dioxide (TiO ₂ ) powder were uniformly mixed at a molar ratio of 94:4:2 and ball milled at a temperature of 650 ° C and a pressure of 760 bar (bar). Hydrogen reduction was carried out for 2 hours; then, grinding was carried out in a high speed mill for 2 hours, and then uniformly filled in a graphite mold. Then, it was preformed with a hydraulic press at a pressure of about 300 psi to form an initial embryo. The priming and the graphite mold are placed in a hot press furnace for sintering, and the hot pressing is performed at a pressure of about 1100 ° C and a pressure of 500 bar for 2 hours, and then the comparative example is obtained. Magnetic alloy sputtering target. In this comparative example, cobalt powder was used as the magnetic substance.

Referring to FIG. 20, the metallographic microstructure of the magnetic alloy sputtering target prepared by the comparative example can be observed that the magnetic alloy sputtering target of the comparative example mainly contains a white phase and a black phase, and Referring to Table 10, it was confirmed by EDS analysis that the white phase was a magnetic base phase composed of cobalt atoms, and the black phase was a titanium magnesium oxide phase composed of Mg ₂ TiO ₄ .

Among them, it can be observed from Fig. 20 that no solid solution of magnesium atoms and titanium atoms is observed in the magnetic base phase, and it is also observed that no solid solution of cobalt atoms is observed in the titanium magnesium oxide phase; As shown in FIG. 10, by the EDS analysis, the magnesium atom and the titanium atom were not detected in the magnetic base phase, and the signal of the cobalt atom was not detected in the titanium magnesium oxide phase, and the magnetic alloy sputtering target of the comparative example was confirmed. The material contains titanium magnesium oxide which does not form a solid solution with the magnetic base phase.

21 is a X-ray diffraction spectrum obtained by XRD analysis of the comparative example, and the X-ray diffraction spectrum of the comparative example is compared with the PDF of JCPDS, and the characteristic peak of the X-ray diffraction spectrum of the comparative example is shown. Matches the characteristic peaks in PDF numbers 05-0727, 15-0806, and 25-1157, where numbers 05-0727 and 15-0806 are diffraction data for crystals composed of cobalt atoms, and numbers 25-1157 are The diffraction data of the crystal of Mg ₂ TiO ₄ shows that the X-ray diffraction spectrum of the comparative example contains a characteristic peak of a crystal composed of Mg ₂ TiO ₄ , and has high crystallinity.

From the results of SEM, EDS, and XRD analysis, it was found that the Mg ₂ TiO ₄ contained in the magnetic alloy sputtering target of the comparative example was a crystalline structure after sintering, and the titanium magnesium oxide phase was crystallized ( In the crystalline phase, the magnetic alloy sputtering target of the present embodiment contains a crystalline phase composed of Mg ₂ TiO ₄ , and thus has low wettability, so that it is difficult to coat the crystal grains of the magnetic phase, so Examples 1 to 8 have magnetic exchange coupling between grains which effectively block the magnetic base phase.

Referring to FIGS. 22A and 22B, a TEM image of a magnetic recording layer prepared by sputtering of a magnetic alloy sputtering target of the comparative example can be used to obtain a titanium-magnesium oxide phase composed of Mg ₂ TiO ₄ . 10A is a crystalline phase which is located between adjacent two crystal grains 20A of the magnetic base phase, that is, on the grain boundary between adjacent two crystal grains 20A, but further with Embodiment 2 (please refer to FIGS. 5A and 5B) After comparison, it was found that the crystal grains 20A of the magnetic base phase of Comparative Example 2 were less pronounced than those of the crystal grains 20 of Example 2, and it was judged that the titanium magnesium oxide phase 10A of Comparative Example 2 could not completely coat the magnetic properties. Since each of the crystal grains 20A of the base phase, Comparative Example 1 could not achieve the effect of the magnetic exchange coupling between the crystal grains which effectively blocked the magnetic base phase as in the second embodiment.

It is confirmed by experimental results that the amorphous phase composed of MgB ₄ O ₇ , Mg ₂ B ₂ O ₅ and Mg ₃ B ₂ O ₆ is indeed good after the high temperature vacuum hot pressing process of the magnetic alloy sputtering target of the present invention. The high temperature stability, uniform and small grain size distribution, can prevent arcing during sputtering and improve the stability of sputtering and product yield. On the other hand, the magnetic recording layer for a magnetic recording medium made of the magnetic alloy sputtering target of the present invention is also formed of MgB ₄ O ₇ , Mg ₂ B ₂ O ₅ , Mg ₃ B ₂ O ₆ . The amorphous phase coats the crystal grains of the magnetic base phase, thereby improving the signal noise ratio, the magnetic crystal anisotropy constant and the coercive force of the magnetic recording medium, so that the demand for the high-density magnetic recording medium can be achieved.

Claims (13)

A magnetic alloy sputtering target comprising: a magnetic base phase; and an amorphous phase comprising a first oxide, the first oxide component being selected from the group consisting of MgB ₄ O ₇ , Mg ₂ B A group consisting of ₂ O ₅ , Mg ₃ B ₂ O ₆ and combinations thereof. The magnetic alloy sputtering target of claim 1, wherein the first oxide is present in an amount of from 1.5 to 8 mole percent of the overall magnetic alloy sputtering target. The magnetic alloy sputtering target of claim 1 or 2, wherein the magnetic base phase comprises cobalt or iron. The magnetic alloy sputtering target according to claim 3, wherein the magnetic phase phase comprises at least one magnetic alloy selected from the group consisting of cobalt platinum alloy, cobalt chromium platinum alloy, and iron platinum alloy. The magnetic alloy sputtering target according to claim 1 or 2, further comprising a second oxide different from the first oxide, the second oxide comprising at least one selected from the group consisting of aluminum and titanium a metal element in a group of bismuth, chromium, gallium, magnesium, and iron. The magnetic alloy sputtering target of claim 5, wherein the second oxide comprises from 0.1 to 9 mole percent of the overall magnetic alloy sputtering target. A recording layer for a magnetic recording medium, comprising: a magnetic base phase; and an amorphous phase comprising a first oxide, the first oxide component being selected from the group consisting of MgB ₄ O ₇ , Mg A group consisting of ₂ B ₂ O ₅ , Mg ₃ B ₂ O ₆ and combinations thereof. The recording layer for a magnetic recording medium according to claim 7, which is made of the magnetic alloy sputtering target according to any one of claims 1 to 6. The recording layer for a magnetic recording medium according to claim 7 or 8, wherein the first oxide accounts for 1.5 to 8 mol% of the recording layer for the magnetic recording medium as a whole. A recording layer for a magnetic recording medium according to claim 7 or 8, wherein the magnetic base phase contains cobalt or iron. The recording layer for a magnetic recording medium according to claim 10, wherein the magnetic base phase comprises at least one magnetic alloy selected from the group consisting of cobalt platinum alloy, cobalt chromium platinum alloy, and iron platinum alloy. The recording layer for a magnetic recording medium according to claim 7 or 8, further comprising a second oxide different from the first oxide, the second oxide comprising at least one selected from the group consisting of aluminum, a metal element in a group of titanium, tantalum, chromium, gallium, magnesium, and iron. The recording layer for a magnetic recording medium according to claim 12, wherein the second oxide accounts for 0.1 to 9 mol% of the recording layer for the magnetic recording medium as a whole.