TWI642800B - Co-pt-re-based sputtering target, method of making the same, and magnetic recording layer - Google Patents

Abstract

The present invention provides a cobalt platinum rhodium sputtering target, a preparation method thereof and a magnetic recording layer. The cobalt platinum ruthenium sputter target and the magnetic recording layer have a similar composition, comprising cobalt, platinum and rhodium, the ruthenium content being greater than or equal to 0.2 atomic percent and less than or equal to 3.5 atomic percent, and the platinum content relative to cobalt and The ratio of the content of platinum is greater than or equal to 0.15 and less than or equal to 0.3. By controlling the composition of the cobalt-platinum-ruthenium-based sputtering target and the magnetic recording layer, it is possible to improve the saturation magnetization amount, the magnetocrystalline anisotropy constant, and the grain size uniformity of the magnetic recording layer, thereby making the magnetic recording layer-containing layer The magnetic recording medium has a high magnetic recording density and a good recording quality.

Description

Cobalt-platinum-ruthenium-based sputtering target, preparation method thereof and magnetic recording layer

The present invention relates to the field of magnetic recording media, and more particularly to a method for preparing a cobalt-platinum-based sputtering target for sputtering a magnetic recording layer, a cobalt-platinum-based sputtering target, and sputtering using the target. Magnetic recording layer.

As people's demand for data storage capacity of magnetic recording media is increasing, how to improve the recording density of magnetic recording media has been a research topic actively developed by the industry. In order to meet the demand for high recording density in the market, the prior art mostly uses a Co-Pt-based alloy system as the main component of the magnetic recording layer, and adds elements such as chromium or ruthenium to the cobalt-platinum alloy system. In an attempt to increase the magnetic recording density of magnetic recording media.

However, the effect of using chrome or tantalum to increase the magnetic recording density of a magnetic recording medium is rather limited, and the magnetic recording layer of such an alloy system mostly has grain size unevenness, saturated magnetization (Ms) and magnetocrystalline anisotropy. The problem of insufficient magnetocrystalline anisotropy (Ku) is even deteriorating the recording quality of magnetic recording media.

In view of the technical defects existing in the prior art, one of the purposes of the present invention is to improve the saturation magnetization and the magnetocrystalline anisotropy constant of the magnetic recording layer, and another object is to improve the grain size uniformity of the magnetic recording layer, thereby making the magnetic inclusion The magnetic recording medium of the recording layer has a high magnetic recording density and a preferable recording quality.

In order to achieve the foregoing objectives, the present invention provides a cobalt platinum-iridium-based sputtering target for sputtering a magnetic recording layer, a cobalt-platinum-based sputtering target, and a magnetic recording applicable to a magnetic recording medium. Floor.

Cobalt platinum rhodium-based sputtering target

The cobalt-platinum-based sputtering target of the present invention comprises cobalt, platinum and rhodium, based on the total number of atoms of the total cobalt-platinum-based sputtering target, and the cerium content is greater than or equal to 0.2 atomic percent (at%) and less than or Equal to 3.5 at%, the ratio of the platinum content to the sum of the content of cobalt and platinum (Pt/(Co+Pt)) is greater than or equal to 0.15 and less than or equal to 0.3.

According to the present invention, the cobalt-platinum ruthenium-based sputtering target can be used as a magnetic recording medium by sputtering a cobalt-platinum-based sputtering target. The magnetic recording layer of the heat-assisted magnetic recording medium, whereby the magnetic recording layer has a higher magnetic recording density and better recording quality. (1) Containing at least three metal components: cobalt, platinum, and rhodium; (2) Re content is greater than or equal to 0.2 at% and less than or equal to 3.5 at%; (3) Pt/(Co+Pt) is greater than or equal to 0.15 And less than or equal to 0.3.

Preferably, the cerium content is greater than or equal to 0.3 at% and less than or equal to 3 at% based on the total number of atoms of the total cobalt-platinum ruthenium sputter target; more preferably, the cerium content is greater than or equal to 0.5 at%. And less than or equal to 3 at%; even more preferably, the cerium content is greater than or equal to 0.6 at% and less than or equal to 2.5 at%.

Preferably, the Pt/(Co+Pt) system is greater than or equal to 0.2 and less than or equal to 0.25.

Preferably, the cobalt platinum rhodium-based sputtering target contains an additive component which is chromium, cerium or a combination thereof. The content of the added component is greater than 0 at% and less than or equal to 4.5 at% based on the total number of atoms of the overall cobalt-platinum-based sputtering target. Specifically, when the additive component is chromium or bismuth, the chromium content or the cerium content is greater than 0 at% and less than or equal to 4.5 at%; when the additive component is a combination of chromium and cerium, the sum of the chromium content and the cerium content is Greater than 0 at% and less than or equal to 4.5 at%.

Preferably, the content of the additive component is greater than or equal to 1 at% and less than or equal to 2 at% based on the total number of atoms of the total cobalt-platinum-based sputtering target.

Preferably, the cobalt platinum rhodium-based sputtering target contains an oxide comprising cerium oxide, titanium oxide, chromium oxide, cobalt oxide, boron oxide or a combination thereof, as a whole cobalt platinum ruthenium group. The total number of moles of the sputter target is based on the oxide content of more than 0 mol% and less than or equal to 30 mol%. The cerium oxide such as cerium oxide (SiO ₂ ), titanium oxide such as titanium dioxide (TiO ₂ ), chromium oxide such as chromium oxide (Cr ₂ O ₃ ), cobalt oxide such as cobalt oxide (Co _{2 )} O ₃ ), cobalt monoxide (CoO), boron oxide such as boron trioxide (B ₂ O ₃ ), but is not limited thereto.

Specifically, when the oxide in the cobalt-platinum-based sputtering target is a single type of oxide, the individual content of the oxide is greater than 0 mol% and less than or equal to 30 mol%; when the cobalt-platinum-based ruthenium is splashed When the oxide in the plating target is a combination of a plurality of oxides, the total content of the oxide (that is, the sum of the contents of the various oxides) is more than 0 mol% and less than or equal to 30 mol%.

Preferably, the content of the oxide is greater than or equal to 15 mol% and less than or equal to 30 mol% based on the total number of atoms of the entire cobalt-platinum-based sputtering target.

According to the present invention, the cobalt platinum rhodium-based sputtering target may be a cobalt platinum rhodium-based alloy target or a cobalt platinum rhodium-based oxide target. That is, the cobalt platinum rhodium-based sputtering target may be a cobalt platinum rhodium-based alloy target composed of a plurality of metal components, for example, a Co-Pt-Re alloy target, a Co-Pt-Re-Cr alloy target. , but not limited to, a Co-Pt-Re-Ru alloy target, a Co-Pt-Re-Cr-Ru alloy target; or the cobalt-platinum-based sputtering target may be blended with a plurality of metal components A cobalt platinum ruthenium-based oxide target composed of an oxide, for example, a Co-Pt-Re-Co ₂ O ₃ oxide target, a Co-Pt-Re-Cr ₂ O ₃ oxide target, and a Co-Pt -Re-Cr-Co ₂ O ₃ oxide target, Co-Pt-Re-Cr-Cr ₂ O ₃ oxide target, Co-Pt-Re-Ru-Co ₂ O ₃ oxide target, Co- Pt-Re-Ru-Cr ₂ O ₃ oxide target, but not limited to this.

Cobalt-platinum-ruthenium-based sputtering target method

The preparation method of the cobalt-platinum-based sputtering target of the present invention includes the use of a smelting method (for example, vacuum induction melting (VIM)) or powder metallurgy (PM) as described above. The cobalt platinum rhodium-based sputtering target has the composition as described above.

In one embodiment, when a cobalt platinum rhodium-based sputtering target is prepared by a smelting method, the metal raw material is placed in a vacuum environment of 0.01 to 0.001 Torr to be higher than the pouring temperature by 5 ° C to 100 ° C. After the temperature is maintained, the metal raw material is cast and smelted at a temperature of 1200 ° C to 1700 ° C to obtain the cobalt platinum rhodium-based sputtering target. Herein, the metal raw material comprises cobalt, platinum and rhodium, based on the total number of atoms of the whole metal raw material, the cerium content is greater than or equal to 0.2 at% and less than or equal to 3.5 at%, and the platinum content is relative to the content of cobalt and platinum. The ratio of the sum is greater than or equal to 0.15 and less than or equal to 0.3.

Preferably, the cerium content is greater than or equal to 0.3 at% and less than or equal to 3 at% based on the total number of atoms of the overall metal raw material; more preferably, the cerium content is greater than or equal to 0.5 at% and less than or equal to 3 at Further preferably, the cerium content is greater than or equal to 0.6 at% and less than or equal to 2.5 at%.

Preferably, in the foregoing metal raw material, Pt/(Co+Pt) is greater than or equal to 0.2 and less than or equal to 0.25.

Preferably, the metal raw material may be further blended with an additive component, and the additive component is chromium, ruthenium or a combination thereof, and the content of the additive component is greater than 0 at% and less than or equal to 4.5 based on the total number of atoms of the overall metal raw material. At%.

In another embodiment, when a cobalt-platinum-based sputter target is prepared by powder metallurgy, the raw material powder is subjected to hydrogen reduction at a temperature of 400 ° C to 800 ° C to obtain a reduced powder; The reduced powder is pre-formed at a pressure of 2000 psi to 6000 psi to obtain the cobalt platinum ruthenium sputter target. Herein, the raw material powder comprises cobalt powder, platinum powder and cerium powder, and the content of the cerium powder is greater than or equal to 0.2 at% and less than or equal to 3.5 at% based on the total number of atoms of the whole raw material powder, and the content of the platinum powder The ratio of the sum of the content of the cobalt powder and the platinum powder is greater than or equal to 0.15 and less than or equal to 0.3.

Preferably, the content of the cerium powder is greater than or equal to 0.3 at% and less than or equal to 3 at% based on the total number of atoms of the whole raw material powder; more preferably, the cerium powder content is greater than or equal to 0.5 at% and less than Or equal to 3 at%; even more preferably, the content of the cerium powder is greater than or equal to 0.6 at% and less than or equal to 2.5 at%.

Preferably, the raw material powder may be further blended with an additive component, which is a chromium powder, a cerium powder or a combination thereof, and the content of the additive component is greater than 0 at% and less than or based on the total number of atoms of the whole raw material powder. Equal to 4.5 at%.

Preferably, the raw material powder may further contain an oxide containing cerium oxide, titanium oxide, chromium oxide, cobalt oxide, boron oxide or a combination thereof, and the total number of moles of the whole raw material powder is The basis, the content of the oxide is more than 0 mol% and less than or equal to 30 mol%.

Magnetic recording layer

The magnetic recording layer of the present invention can be sputtered by a cobalt-platinum-based sputtering target as described above, and the magnetic recording layer can have a composition such as a cobalt-platinum-ruthenium-based sputtering target. The magnetic recording layer comprises cobalt, platinum and rhodium, based on the total number of atoms of the whole magnetic recording layer, the cerium content is greater than or equal to 0.2 at% and less than or equal to 3.5 at%, and the platinum content is relative to the content of cobalt and platinum. The ratio (Pt/(Co+Pt)) is greater than or equal to 0.15 and less than or equal to 0.3.

According to the present invention, since the composition of the magnetic recording layer can simultaneously satisfy the above conditions (1) to (3), the saturation magnetization amount, the magnetocrystalline anisotropy constant, and the grain size uniformity of the magnetic recording layer can be specifically improved. The magnetic recording layer can simultaneously have the following three characteristics: (A) Ku exceeds 8.0 Í ^{10 6} erg/cc; (B) Ms exceeds 800 emu/cc; and (C) particle size uniformity is less than 30%. Therefore, the magnetic recording layer of the present invention can be applied to various magnetic recording media (for example, heat-assisted magnetic recording media), and is advantageous for improving the magnetic recording density and recording quality of the magnetic recording medium.

Preferably, the cerium content is greater than or equal to 0.3 at% and less than or equal to 3 at% based on the total number of atoms of the integral magnetic recording layer; more preferably, the cerium content is greater than or equal to 0.5 at% and less than or equal to 3 Further preferably, the cerium content is greater than or equal to 0.6 at% and less than or equal to 2.5 at%.

Preferably, the magnetic recording layer contains an additive component which is chromium, ruthenium or a combination thereof. The content of the added component is greater than 0 at% and less than or equal to 4.5 at% based on the total number of atoms of the overall magnetic recording layer. Specifically, when the additive component is chromium or bismuth, the chromium content or the cerium content is greater than 0 and less than or equal to 4.5 at%; when the additive component is a combination of chromium and cerium, the sum of the chromium content and the cerium content is greater than 0. At% and less than or equal to 4.5 at%. Preferably, the content of the additive component is greater than or equal to 1 at% and less than or equal to 2 at% based on the total number of atoms of the integral magnetic recording layer.

Preferably, the magnetic recording layer contains an oxide comprising cerium oxide, titanium oxide, chromium oxide, cobalt oxide, boron oxide or a combination thereof, wherein the total number of moles of the entire magnetic recording layer is The basis, the content of the oxide is more than 0 mol% and less than or equal to 30 mol%. Specifically, when the oxide contained in the magnetic recording layer is a single type of oxide, the individual content of the oxide is more than 0 mol% and less than or equal to 30 mol%; when the oxidation contained in the magnetic recording layer When the composition is a combination of a plurality of oxides, the total content of the oxides (i.e., the sum of the contents of the various oxides) is more than 0 mol% and less than or equal to 30 mol%. Preferably, the content of the oxide is greater than or equal to 15 mol% and less than or equal to 30 mol% based on the total number of moles of the integral magnetic recording layer.

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 to 15 And comparative examples 1 to 6

The cobalt platinum rhodium-based sputtering targets of Examples 1 to 15 and Comparative Examples 2 to 6 and the cobalt platinum sputtering target of Comparative Example 1 were roughly obtained by vacuum melting as described below:

According to the composition of the sputtering target shown in Table 1 below, an appropriate amount of cobalt (Co, purity 99.95% (3N5)), platinum (Pt, purity 3N5), ruthenium (Re, purity 3N5) was placed in the alumina crucible. , chromium (Cr, purity 3N5), antimony (Ru, purity 3N5), and placed in the reaction chamber; then, using vacuum melting, in a vacuum environment of 5 × 10 ^-2 Torr, above the water temperature of 100 After the temperature is maintained at °C, the metal raw material is cast at a temperature of 1500 ° C to 1750 ° C to obtain an alloy ingot; finally, computer numerical control (CNC) lathe processing is performed to obtain a diameter of 2溅, sputtering target with a thickness of 3 mm.

As shown in Table 1 below, the differences between Examples 1 to 15 and Comparative Examples 1 to 6 mainly depend on the content of each metal component in the sputtering target. In the cobalt-platinum-based sputtering targets of Examples 1 to 15, the composition of the cobalt-platinum-ruthenium-based sputtering target simultaneously meets the following conditions: (1) at least three metal components of cobalt, platinum, and rhodium; (2) The content of Re is greater than or equal to 0.2 at% and less than or equal to 3.5 at%; (3) Pt/(Co+Pt) is greater than or equal to 0.15 and less than or equal to 0.3.

In contrast, the cobalt platinum sputtering target of Comparative Example 1 was not blended with the bismuth component, and thus the conditions of the above (1) and (2) were not satisfied. The cobalt-platinum-based sputtering targets of Comparative Examples 2 to 4 contain three metal components of cobalt, platinum and rhodium, and moderately control the content of platinum and cobalt, but the content of cerium exceeds 0.2 at% to 3.5 at%. Within the range, the condition of the above (2) is also not satisfied. The cobalt-platinum-based sputtering targets of Comparative Examples 5 and 6 contain three metal components of cobalt, platinum and rhodium, and moderately control the content of cerium, but do not moderately control the content of platinum and cobalt, resulting in Pt in the composition. /(Co+Pt) has also exceeded the range of 0.15 to 0.3, and thus the condition of the above (3) has not been satisfied.

Example 16 and 17

The cobalt platinum rhodium-based sputtering targets of Examples 16 and 17 were prepared by powder metallurgy as follows:

According to the composition of the sputtering target shown in Table 1 below, an appropriate amount of cobalt powder (Co, purity 3N5), platinum powder (Pt, purity 3N5), cerium powder (Re, purity 3N5) and oxide were uniformly mixed and ball milled. Thereafter, hydrogen reduction was carried out at a temperature of 650 ° C under a pressure of 760 bar for 2 hours to obtain a reduced powder. Then, the reduced powder is ground in a high speed grinder for 2 hours, uniformly filled in a graphite mold, and preformed by a hydraulic press at a pressure of about 1500 psi to form an initial embryo; the embryo and the graphite are further formed. The mold was placed in a hot press furnace for sintering, and sintered at a sintering temperature of 1100 ° C and a sintering pressure of 422 bar for 3 hours. Finally, it was processed by a CNC lathe to obtain a diameter of 2 吋 and a thickness of 3 mm. Sputter target.

The cobalt platinum rhodium-based sputtering targets of Examples 16 and 17 further contain a specific kind of oxide in addition to the metal component, compared to the cobalt platinum rhodium-based sputtering targets of Examples 1 to 15, wherein Example 16 The cobalt-platinum-bismuth-based sputtering target contains oxides of cerium, chromium and boron, and the content of SiO ₂ is 6 mol% based on the total number of moles of the entire cobalt-platinum-based sputtering target, Cr ₂ O ₃ The content of 4 mol% and the content of B ₂ O ₃ is 5 mol%; the cobalt-platinum-based sputtering target of Example 17 contains oxides of titanium, lanthanum and cobalt, and is sputtered as a whole cobalt-platinum-based ruthenium. The total number of moles of the target is based on the reference, the content of SiO ₂ is 12 mol%, the content of TiO ₂ is 8 mol%, and the content of CoO is 10 mol%. As shown in Table 1 below, the cobalt platinum rhodium-based sputtering targets of Examples 16 and 17 also met the conditions of the above (1) to (3).

Example 1A to 17A Comparative example 1A to 6A

Taking the cobalt platinum ruthenium sputter target of the above Examples 1 to 17, the cobalt platinum sputter target of Comparative Example 1, and the cobalt platinum ruthenium sputter target of Comparative Examples 2 to 6, according to the same process parameters, The magnetic recording layers of Examples 1A to 17A and Comparative Examples 1A to 6A were separately sputter-plated by magnetron sputtering. The detailed sputtering method is described later.

First, each sputter target is placed in a magnetron sputtering machine (label: Gao Dun), first with a power of 200 watts (W), a pressure of 3 mTorr (mtorr) and a standard of 30 milliliters. /min (sccm) of argon in a sputtering environment for 600 seconds, a pre-sputter process to remove surface contamination; then 50 to 100 W power, 10 ^-2 to 10 ^-3 torr pressure Continuous sputtering for 15 to 30 minutes, sputtering on the substrate to form a Ru intermediate layer with a film thickness of 50 nm; finally, continuously sputtering 15 to 30 at a power of 50 to 100 W and a pressure of 10 ^-2 to 10 ^-3 torr In a minute, a magnetic recording layer having a film thickness of 18 nm was formed by sputtering on a substrate to obtain the composite film layer.

Herein, the composition of the magnetic recording layer in the composite film layers of Examples 1A to 17A and Comparative Examples 1A to 6A is substantially the same as those of Examples 1A to 17A and Comparative Example 1A shown in Table 1 below through the sputtering process described above. The composition of the 6A sputter target is similar.

Test case 1 : saturation magnetization and magnetocrystalline anisotropy constant

In this test example, the composite film layers of Examples 1A to 17A and Comparative Examples 1A to 6A were taken as samples to be tested, and a vibrating sample magnetometer (VSM) was used at room temperature, -12,000 to +12000 Å (Oe). The saturation magnetization (unit: emu/cc) and the magnetocrystalline anisotropy constant (unit: erg/) of the composite layers of Examples 1A to 17A and Comparative Examples 1A to 6A at room temperature were measured under a magnetic field. Cc), the results are shown in Table 1 below.

Test case 2 : Grain size uniformity

In this test example, the composite film layers of Examples 1A to 17A and Comparative Examples 1A to 6A were taken as samples to be tested, and the magnetic recording layer on the surface of each sample to be tested was observed by a transmission electron microscope, and each sample to be tested was observed. The grain size of the magnetic recording layer was measured in a transmission electron microscope image.

Here, the percentage calculated by dividing the standard deviation by the average grain size is expressed as a normalized uniformity of grain size, that is, the grain shown in Table 1 below. Dimensional uniformity in percent (%). In Table 1 below, the smaller the percentage of grain size uniformity, the better the uniformity of the grain size.

Discussion of experimental results

As shown in Table 1 below, the cobalt platinum ruthenium sputter targets of Examples 1 to 17 simultaneously conform to (1) at least three metal components of cobalt, platinum, and rhodium; and (2) the content of Re is greater than or equal to 0.2 at%. And less than or equal to 3.5 at%; (3) Pt / (Co + Pt) is greater than or equal to 0.15 and less than or equal to 0.3, so the magnetic recording by the cobalt-platinum-based sputtering target is sputtered The layers (i.e., the magnetic recording layers of Examples 1A to 17A) can simultaneously have the following three excellent effects: (A) Ku exceeds 8.0 Í ^{10 6} erg/cc; (B) Ms exceeds 800 emu/cc; and (C) The particle size uniformity is less than 30%.

Therefore, when the magnetic recording layer sputtered by the cobalt platinum ruthenium sputter target of Examples 1 to 17 is applied to a horizontal magnetic recording medium, a vertical magnetic recording medium or a heat assisted magnetic recording medium, it can contribute to Improve the magnetic recording density and recording quality of magnetic recording media to meet current market demands.

In contrast, the cobalt-platinum sputtering target of Comparative Example 1 has a magnetic recording layer which is sputtered by the aforementioned cobalt-platin sputtering target because the composition contains only cobalt and platinum and is not doped with germanium (ie, comparison) The magnetic recording layer of Example 1A still had the disadvantage of uneven grain size, and the above effect (C) could not be obtained. Looking at the cobalt-platinum-based sputtering targets of Comparative Examples 2 and 3, which contain a bismuth component and an appropriate amount of cobalt and platinum components, the ruthenium content of the cobalt-platinum ruthenium-based sputtering target is less than 0.2 at%, resulting in utilization. The magnetic recording layer in which the cobalt platinum sputtering target was sputtered (that is, the magnetic recording layers of Comparative Examples 2A and 3A) still had a disadvantage of uneven grain size, and the above effect (C) could not be obtained. Further, in the cobalt platinum ruthenium sputter target of Comparative Example 4, since the ruthenium content exceeds 3.5 at%, it is difficult to enhance the magnetic recording layer which is sputtered by the aforementioned cobalt platinum sputtering target (ie, Comparative Example 4A). Ms and Ku of the magnetic recording layer), the above effects (A) and (B) cannot be obtained.

Looking at the cobalt-platinum-based sputtering target of Comparative Example 5, although it contains an appropriate amount of antimony component, the ratio of Pt/(Co+Pt) is less than 0.15, so that the target is splashed by the cobalt platinum sputtering target. The plated magnetic recording layer (i.e., the magnetic recording layer of Comparative Example 5A) still had the disadvantage of low Ku, and the above effect (A) could not be obtained. In addition, the cobalt platinum rhodium-based sputtering target of Comparative Example 6 has a magnetic recording layer which is sputtered by the aforementioned cobalt platinum sputtering target because the ratio of Pt/(Co+Pt) exceeds 0.3 (ie, comparison) The magnetic recording layer of Example 6A still has the disadvantage of low Ms, and the above effect (B) cannot be obtained.

It can be seen that the cobalt platinum sputtering target of Comparative Example 1 and the cobalt platinum ruthenium sputtering target of Comparative Examples 2 to 6 fail to simultaneously conform to (1) at least three metal components of cobalt, platinum and rhodium; 2) Re content is greater than or equal to 0.2 at% and less than or equal to 3.5 at%; (3) Pt / (Co + Pt) is greater than or equal to 0.15 and less than or equal to 0.3, so the use of the aforementioned sputtering target The sputtered magnetic recording layer cannot simultaneously have (A) Ku more than 8.0 Í ^{10 6} erg/cc; (B) Ms exceed 800 emu/cc; and (C) particle size uniformity is less than 30%, etc. Characteristics and effects, of course, cannot achieve the purpose of improving the recording density and recording quality of magnetic recording media.

Further study on the composition of the cobalt-platinum-based sputtering target of Examples 3, 4, 6, 7, 10, 11, 13 to 15 can be seen, when the cobalt-platinum-based sputtering target contains cobalt, platinum, and rhodium components. When the chromium or antimony component is further controlled to further control the content of the chromium or antimony component to more than 0 at% and less than or equal to 4.5 at%, the magnetic recording layer which is sputtered by the cobalt-platinum-based sputter target can be ensured ( That is, the magnetic recording layers of Examples 3A, 4A, 6A, 7A, 10A, 11A, and 13A to 15A have both the above-described excellent effects (A) to (C).

Further, the composition of the cobalt-platinum-based sputtering target of Examples 16 and 17 can be further observed. When the cobalt-platinum-based sputtering target is further added with an oxide of 30 mol% or less, the cobalt platinum-ruthenium group can be ensured. The magnetic recording layers (i.e., the magnetic recording layers of Examples 16A and 17A) sputtered by the sputtering target simultaneously have the above-described excellent effects (A) to (C).

Further comparing the cobalt platinum ruthenium sputter targets of Examples 5 and 9 with the cobalt platinum ruthenium sputter targets of Examples 1 to 4, 6 to 8, 10 to 17, it can be found that when the cobalt platinum ruthenium sputtering is splashed When the content of Re in the plating target is controlled to be greater than or equal to 0.3 at% and less than or equal to 3 at%, the particle size uniformity of the magnetic recording layer sputtered by the cobalt-platinum-based sputtering target can be further improved. The particle size uniformity is further reduced to less than 26%. In addition, the cobalt platinum ruthenium sputter targets of Examples 5 to 7, 9 and 10 were further compared with the cobalt platinum ruthenium sputter targets of Examples 1 to 4, 8, and 11 to 17, and cobalt was found. When the content of Re in the platinum-iridium-based sputtering target is controlled to be 0.6 at% or more and 2.5 at% or less, the magnetic recording layer of the cobalt-platinum-based sputtering target is further ensured. The particle size uniformity is reduced to less than 23%.

In summary, the present invention can control the composition of the cobalt-platinum-ruthenium-based sputtering target to enable the coating of the cobalt-platinum-based sputtering target to have a high saturation magnetization and high magnetic properties. The characteristics of the crystal anisotropy constant and the uniform crystal grain size make the film layer suitable for the magnetic recording layer of the magnetic recording medium, so that the magnetic recording medium containing the magnetic recording layer has a higher magnetic recording density and Better recording quality. Table 1: Composition of the cobalt platinum ruthenium sputter target of Examples 1 to 17, the cobalt platinum sputter target of Comparative Example 1, and the cobalt platinum ruthenium sputter target of Comparative Examples 2 to 6 and the use of the aforementioned sputtering The properties of the magnetic recording layers of Examples 1A to 17A and Comparative Examples 1A to 6A were respectively sputtered.  <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> Sputtering target sample number</td><td> Co (at%) </td ><td> Pt (at%) </td><td> Re (at%) </td><td> Cr (at%) </td><td> Ru (at%) </td>< Td> oxide (mol%) </td><td> Pt/(Co+Pt) </td><td> magnetic recording layer sample number </td><td> Ku (erg/cc) </td ><td> Ms (emu/cc) </td><td> Grain size uniformity</td></tr><tr><td> Example 1 </td><td> 73.5 </td ><td> 24.5 </td><td> 2 </td><td> 0 </td><td> 0 </td><td> 0 </td><td> 0.25 </td>< Td> Example 1A </td><td> 9.24Í10⁶</td><td> 856 </td><td> 18% </td></tr><tr> <td> Embodiment 2 </td><td> 74 </td><td> 25 </td><td> 1 </td><td> 0 </td><td> 0 </td> <td> 0 </td><td> 0.25 </td><td> Example 2A </td><td> 9.08Í10⁶</td><td> 848 </td ><td> 16% </td></tr><tr><td> Example 3 </td><td> 73 </td><td> 24 </td><td> 1 </td ><td> 2 </td><td> 0 </td><td> 0 </td><td> 0.25 </td><td> Example 3A </td><td> 8.56Í10<sup >6</sup></td><td> 855 </td><td> 10% </td></tr><tr><td> Example 4 </td><td> 71 </ Td><t d> 23.5 </td><td> 1 </td><td> 4.5 </td><td> 0 </td><td> 0 </td><td> 0.25 </td><td> Example 4A </td><td> 8.33Í10⁶</td><td> 828 </td><td> 18% </td></tr><tr><td > Example 5 </td><td> 74.4 </td><td> 25.4 </td><td> 0.2 </td><td> 0 </td><td> 0 </td><td > 0 </td><td> 0.25 </td><td> Example 5A </td><td> 9.89Í10⁶</td><td> 909 </td>< Td> 28% </td></tr><tr><td> Example 6 </td><td> 73 </td><td> 24.7 </td><td> 0.3 </td>< Td> 2 </td><td> 0 </td><td> 0 </td><td> 0.25 </td><td> Example 6A </td><td> 10.21Í10⁶</td><td> 872 </td><td> 26% </td></tr><tr><td> Example 7 </td><td> 73 </td> <td> 24.5 </td><td> 0.5 </td><td> 2 </td><td> 0 </td><td> 0 </td><td> 0.25 </td><td > Example 7A </td><td> 9.97Í10⁶</td><td> 863 </td><td> 25% </td></tr><tr>< Td> Example 8 </td><td> 77.4 </td><td> 22 </td><td> 0.6 </td><td> 0 </td><td> 0 </td>< Td> 0 </td><td> 0.22 </td><td> Example 8A </td><td> 10.48Í10⁶</td><td> 950 </td> <td> 23% </td></tr><tr><td> Example 9 < /td><td> 72.5 </td><td> 24 </td><td> 3.5 </td><td> 0 </td><td> 0 </td><td> 0 </td ><td> 0.25 </td><td> Example 9A </td><td> 8.05Í10⁶</td><td> 808 </td><td> 29% < /td></tr><tr><td> Example 10 </td><td> 72 </td><td> 24 </td><td> 3 </td><td> 1 </ Td><td> 0 </td><td> 0 </td><td> 0.25 </td><td> Example 10A </td><td> 8.15Í10⁶< /td><td> 820 </td><td> 24% </td></tr><tr><td> Example 11 </td><td> 72 </td><td> 24.5 < /td><td> 2.5 </td><td> 1 </td><td> 0 </td><td> 0 </td><td> 0.25 </td><td> Example 11A < /td><td> 8.32Í10⁶</td><td> 845 </td><td> 20% </td></tr><tr><td> Example 12 </td><td> 83 </td><td> 15 </td><td> 2 </td><td> 0 </td><td> 0 </td><td> 0 </ Td><td> 0.15 </td><td> Example 12A </td><td> 8.15Í10⁶</td><td> 920 </td><td> 22% </td></tr><tr><td> Example 13 </td><td> 68 </td><td> 29.5 </td><td> 1.5 </td><td> 1 < /td><td> 0 </td><td> 0 </td><td> 0.30 </td><td> Example 13A </td><td> 9.88Í10⁶ </td><td> 815 </td><td> 16% </td></tr><tr><t d> Example 14 </td><td> 73 </td><td> 24 </td><td> 1 </td><td> 0 </td><td> 2 </td>< Td> 0 </td><td> 0.25 </td><td> Example 14A </td><td> 9.25Í10⁶</td><td> 866 </td> <td> 12% </td></tr><tr><td> Example 15 </td><td> 71 </td><td> 23.5 </td><td> 1 </td> <td> 0 </td><td> 4.5 </td><td> 0 </td><td> 0.25 </td><td> Example 15A </td><td> 9.10Í10⁶</td><td> 850 </td><td> 15% </td></tr><tr><td> Example 16 </td><td> 62.9 </td ><td> 21.25 </td><td> 0.85 </td><td> 0 </td><td> 0 </td><td> 15 </td><td> 0.25 </td>< Td> Example 16A </td><td> 9.40Í10⁶</td><td> 850 </td><td> 15% </td></tr><tr> <td> Example 17 </td><td> 51.8 </td><td> 17.5 </td><td> 0.7 </td><td> 0 </td><td> 0 </td> <td> 30 </td><td> 0.25 </td><td> Example 17A </td><td> 9.09Í10⁶</td><td> 848 </td ><td> 16% </td></tr><tr><td> Comparative Example 1 </td><td> 75 </td><td> 25 </td><td> 0 </td ><td> 0 </td><td> 0 </td><td> 0 </td><td> 0.25 </td><td> Comparative Example 1A </td><td> 9.76Í10<sup >6</sup></td><td> 895 </td><t d> 40% </td></tr><tr><td> Comparative Example 2 </td><td> 75 </td><td> 24.9 </td><td> 0.1 </td>< Td> 0 </td><td> 0 </td><td> 0 </td><td> 0.25 </td><td> Comparative Example 2A </td><td> 10.39 Í10⁶</td><td> 885 </td><td> 38% </td></tr><tr><td> Comparative Example 3 </td><td> 73.5 </td> <td> 24.4 </td><td> 0.1 </td><td> 2 </td><td> 0 </td><td> 0 </td><td> 0.25 </td><td > Comparative Example 3A </td><td> 11.38Í10⁶</td><td> 958 </td><td> 35% </td></tr><tr>< Td> Comparative Example 4 </td><td> 71 </td><td> 24 </td><td> 4 </td><td> 1 </td><td> 0 </td>< Td> 0 </td><td> 0.25 </td><td> Comparative Example 4A </td><td> 6.85Í10⁶</td><td> 730 </td> <td> 28% </td></tr><tr><td> Comparative Example 5 </td><td> 84 </td><td> 14 </td><td> 2 </td> <td> 0 </td><td> 0 </td><td> 0 </td><td> 0.14 </td><td> Comparative Example 5A </td><td> 7.95Í10⁶</td><td> 927 </td><td> 25% </td></tr><tr><td> Comparative Example 6 </td><td> 67 </td ><td> 30.5 </td><td> 1.5 </td><td> 1 </td><td> 0 </td><td> 0 </td><td> 0.31 </td>< Td> Comparative Example 6A </td><td> 9.99Í10⁶</td><td> 780 </td><td> 18% </td></tr></TBODY></TABLE>

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Claims (13)

A cobalt platinum rhodium-based sputtering target comprising cobalt, platinum and rhodium, based on the total number of atoms of the entire cobalt-platinum-based sputter target, the rhodium content being greater than or equal to 0.2 atomic percent and less than or equal to 3.5 atomic percent The ratio of the platinum content to the sum of the content of cobalt and platinum is greater than or equal to 0.15 and less than or equal to 0.3. The cobalt platinum ruthenium sputter target according to claim 1, wherein the ruthenium content is greater than or equal to 0.3 atomic percent and less than or equal to 3 atomic percent based on the total number of atoms of the overall cobalt platinum rhodium sputter target. The cobalt platinum rhodium-based sputtering target according to claim 2, wherein the niobium content is greater than or equal to 0.6 atomic percent and less than or equal to 2.5 atomic percent based on the total number of atoms of the monolithic cobalt platinum rhodium-based sputtering target. The cobalt-platinum-based sputtering target according to any one of claims 1 to 3, wherein the cobalt-platinum-based sputtering target contains an additive component, which is chromium, cerium or a combination thereof, as a whole cobalt The total number of atoms of the platinum ruthenium sputter target is based on the content of the added component being more than 0 atomic percent and less than or equal to 4.5 atomic percent. The cobalt-platinum-based sputtering target according to any one of claims 1 to 3, wherein the cobalt-platinum-based sputtering target contains an oxide containing cerium oxide, titanium oxide, chromium oxide The material, the cobalt oxide, the boron oxide or a combination thereof, based on the total number of moles of the overall cobalt platinum rhodium-based sputtering target, the oxide content is greater than 0 mole percent and less than or equal to 30 mole percent. The cobalt-platinum-based sputtering target according to claim 4, wherein the cobalt-platinum-based sputtering target contains an oxide comprising cerium oxide, titanium oxide, chromium oxide, cobalt oxide, The boron oxide or combination thereof is based on the total number of moles of the overall cobalt platinum rhodium sputter target, and the oxide content is greater than 0 mole percent and less than or equal to 30 mole percent. A method for producing a cobalt platinum rhodium-based sputtering target, which comprises preparing a cobalt platinum rhodium-based sputtering target according to any one of claims 1 to 6 using a smelting method or a powder metallurgy method. A magnetic recording layer comprising cobalt, platinum and rhodium, based on the total number of atoms of the entire magnetic recording layer, the cerium content being greater than or equal to 0.2 atomic percent and less than or equal to 3.5 atomic percent, and the platinum content relative to the cobalt and platinum content The ratio of the sum is greater than or equal to 0.15 and less than or equal to 0.3. The magnetic recording layer according to claim 8, wherein the cerium content is greater than or equal to 0.3 atomic percent and less than or equal to 3 atomic percent based on the total number of atoms of the integral magnetic recording layer. The magnetic recording layer according to claim 9, wherein the cerium content is greater than or equal to 0.6 atomic percent and less than or equal to 2.5 atomic percent based on the total number of atoms of the integral magnetic recording layer. The magnetic recording layer according to any one of claims 8 to 10, wherein the magnetic recording layer contains an additive component which is chromium, ruthenium or a combination thereof, based on the total number of moles of the entire magnetic recording layer. The content of the added component is greater than 0 atomic percent and less than or equal to 4.5 atomic percent. The magnetic recording layer according to any one of claims 8 to 10, wherein the magnetic recording layer contains an oxide comprising cerium oxide, titanium oxide, chromium oxide, cobalt oxide, boron oxide or The combination, based on the total number of moles of the overall magnetic recording layer, is greater than 0 mole percent and less than or equal to 30 mole percent. The magnetic recording layer of claim 11, wherein the magnetic recording layer contains an oxide comprising cerium oxide, titanium oxide, chromium oxide, cobalt oxide, boron oxide or a combination thereof to form a magnetic body The total number of atoms of the recording layer is based on the oxide content of greater than 0 mole percent and less than or equal to 30 mole percent.