Magnetic recording medium and magnetic recording / reproducing apparatus

Abstract

To provide a magnetic recording medium in which perpendicular orientation of a magnetic recording layer is enhanced and further high recording density is made possible, and to provide a magnetic recording and reproducing device provided with the magnetic recording medium.SOLUTION: A magnetic recording medium 1 according to the present invention includes an underlayer 30, a seed layer 40, and a magnetic recording layer 60 in this order on a non-magnetic substrate 10, wherein the seed layer 40 contains two elements phase-separated from each other, one phase of an element α mainly has a columnar crystal of an fcc structure, and the other phase of an element β mainly has an amorphous structure, the underlayer 30 includes a first underlayer 31, a second underlayer 32, and a third underlayer 33 from the side of the non-magnetic substrate 10, the first underlayer 31 mainly contains any of Ru, Cr, and Ni, the second underlayer 32 mainly contains the one element α, and the third underlayer 33 mainly contains any of Ru, Cr, and Mo.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a magnetic recording medium and a magnetic recording and reproducing device. [Background technology]

[0002] Development of magnetic recording media suitable for high recording densities is underway for hard disk drives (HDDs), a type of magnetic recording and reproducing device. Currently available magnetic recording and reproducing devices are equipped with so-called perpendicular magnetic recording media, in which the easy axis of magnetization in the magnetic film is oriented perpendicularly. Perpendicular magnetic recording media have a small demagnetizing field at the boundary regions between recording bits, even when recording densities are increased, resulting in clear bit boundaries and suppressing noise increases. Furthermore, perpendicular magnetic recording media have excellent thermal fluctuation characteristics because they minimize the reduction in recording bit volume associated with increased recording densities.

[0003] As such a perpendicular magnetic recording medium, for example, Patent Document 1 discloses a perpendicular magnetic recording medium that is stacked in this order: a non-magnetic orientation control layer whose main component is at least one selected from the group consisting of silver, palladium, and ruthenium; a non-magnetic seed layer having silver grains with an fcc structure and amorphous germanium grain boundaries; a non-magnetic intermediate layer formed from a ruthenium alloy; and a perpendicular magnetic recording layer formed from cobalt or iron and platinum. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-196752 Summary of the Invention [Problem to be solved by the invention]

[0005] The demand for higher recording densities in magnetic recording media continues unabated, and magnetic recording media are being required to have even better characteristics than ever before. Specifically, to increase the recording density of magnetic recording media, it is necessary to further reduce the size of the magnetic particles that make up the magnetic recording layer and improve the perpendicular orientation of the magnetic particles.

[0006] The present invention has been proposed in view of the above-mentioned conventional circumstances, and aims to provide a magnetic recording medium that improves the perpendicular orientation of the magnetic recording layer, enabling even higher recording densities, and a magnetic recording and reproducing device equipped with such a magnetic recording medium. [Means for solving the problem]

[0007] The present invention provides the following means. [1] A non-magnetic substrate having an underlayer, a seed layer, and a magnetic recording layer in this order on the non-magnetic substrate; the seed layer includes two elements that are phase-separated from each other; On the other hand, the phase of element α has mainly columnar crystals with an fcc structure, The phase of the other element β has a predominantly amorphous structure, the underlayer includes, from the non-magnetic substrate side, a first underlayer, a second underlayer, and a third underlayer, the first underlayer mainly contains any one of Ru, Cr, and Ni, the second underlayer mainly contains the one element α, The magnetic recording medium, wherein the third underlayer mainly contains any one of Ru, Cr, and Mo. [2] The one element α is any one of Ag, Au, Al, and Pd, The magnetic recording medium according to [1], wherein the other element β is either Ge or Si. [3] an intermediate layer between the seed layer and the magnetic recording layer; the intermediate layer is a layer mainly containing Ru, The magnetic recording medium according to [1] or [2], wherein the magnetic recording layer is a layer containing mainly Co, Cr, and Pt. [4] an intermediate layer between the seed layer and the magnetic recording layer; the intermediate layer is a layer mainly containing an NaCl-type compound, The magnetic recording medium according to any one of [1] to [3], wherein the magnetic recording layer is a layer that mainly contains magnetic grains having an L10 structure. [5] A magnetic recording and reproducing device comprising the magnetic recording medium according to any one of [1] to [4]. [Effects of the Invention]

[0008] The present invention improves the perpendicular orientation of the magnetic recording layer, enabling even higher recording densities. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing an example of the configuration of a magnetic recording medium according to an embodiment of the present invention. [Figure 2] 1 is a perspective view showing an example of a magnetic recording and reproducing device to which a magnetic recording medium according to an embodiment of the present invention is applied; DETAILED DESCRIPTION OF THE INVENTION

[0010] Magnetic recording media and magnetic recording / reproducing devices according to embodiments of the present invention will be described in detail below with reference to the drawings. The drawings used in the following description may show characteristic portions enlarged for ease of understanding, and the dimensional ratios of each component element may not necessarily be the same as in reality. In this specification, unless otherwise specified, "to" indicating a numerical range means that the numerical values ​​before and after it are included as the lower and upper limits. Furthermore, when only the upper limit value in a numerical range expressed by "to" is specified in units, the same units are used for the lower limit value.

[0011] Fig. 1 is a cross-sectional view showing an example of the configuration of a magnetic recording medium according to this embodiment. As shown in Fig. 1, the magnetic recording medium 1 according to this embodiment includes a non-magnetic substrate 10, on both sides of which a soft magnetic underlayer 20, an underlayer 30, a seed layer 40, an intermediate layer 50, a magnetic recording layer 60, a protective layer 70, and a lubricating layer 80 are sequentially stacked.

[0012] The magnetic recording medium 1 is a magnetic recording medium comprising an underlayer 30, a seed layer 40, and a magnetic recording layer 60 stacked in this order on a non-magnetic substrate 10. The seed layer 40 contains two elements that are phase-separated from each other, with the phase of one element, α, having a predominantly columnar crystal structure with an fcc structure, and the phase of the other element, β, having a predominantly amorphous structure. The underlayer 30 includes, from the non-magnetic substrate 10 side, a first underlayer 31, a second underlayer 32, and a third underlayer 33. The first underlayer 31 primarily contains one of Ru, Cr, and Ni, the second underlayer 32 primarily contains one of the elements α, and the third underlayer 33 primarily contains one of Ru, Cr, and Mo.

[0013] By using this structure, the magnetic recording medium 1 can reduce the size of the crystal grains constituting the seed layer 40 and improve the orientation of the crystal grains, thereby enabling the columnar crystals starting from the seed layer 40 to be formed with fine grains and high orientation from the intermediate layer 50 to the magnetic recording layer 60. By promoting the reduction in size and magnetic isolation of the magnetic grains contained in the magnetic recording layer 60, the magnetic recording medium 1 can improve the perpendicular orientation of the magnetic recording layer 60 and enable even higher recording densities. Therefore, the magnetic recording medium 1 can significantly improve the signal-to-noise ratio (S / N ratio) during reproduction and improve thermal fluctuation characteristics, thereby demonstrating even better recording characteristics (OW).

[0014] The seed layer 40 is preferably formed using a eutectic alloy in which one element α and the other element β undergo phase separation. In the case of such a eutectic alloy, the phase of one element α tends to form fine crystals with a uniform grain size, and the phase of the other element β tends to form a uniform granular structure by surrounding the crystals of one element α.

[0015] The element α of the seed layer 40 is preferably Ag (having an fcc structure), Au (having an fcc structure), Al (having an fcc structure), or Pd (having an fcc structure), and the other element β is preferably Ge or Si. By using such elements for the element α and the other element β, the alloy constituting the seed layer 40 becomes a eutectic alloy, the phase of the element α becomes fine columnar crystals with a uniform grain size and an fcc structure, and the phase of the other element β becomes an amorphous structure. Therefore, the seed layer 40 tends to have a granular structure consisting of columnar crystals of the element α and the other element β with an amorphous structure surrounding them. It is particularly preferable to use AgGe, AgSi, AlGe, AuGe, or AlSi as the alloy constituting the seed layer 40.

[0016] The thickness of the seed layer 40 is preferably as thin as possible as long as the above structure is maintained, and is preferably, for example, 100 nm or less.

[0017] The underlayer 30 has the effect of enhancing the crystal orientation of the seed layer 40 formed thereon. Specifically, when the columnar crystals of one element α contained in the seed layer 40 have an fcc structure, the underlayer 30 has the effect of enhancing the orientation of the (111) plane or the orientation of the (200) plane.

[0018] The first underlayer 31 is a layer containing primarily any one of Ru, Cr, and Ni, and is a layer that serves as a starting point for crystal orientation. When the columnar crystals of one of the elements α contained in the seed layer 40 have an fcc structure, the first underlayer 31 can enhance the orientation of the (111) plane or the (200) plane.

[0019] Incidentally, "mainly containing one of Ru, Cr and Ni" means that when the most abundant element constituting the first underlayer 31 is one of Ru, Cr and Ni, the content of any of Ru, Cr and Ni is preferably 50 atomic % or more of the elements constituting the first underlayer 31, and includes the case where it is 100 atomic % of the elements constituting the first underlayer 31.

[0020] The thickness of the first underlayer 31 is preferably within the range of 1 to 10 nm.

[0021] The second underlayer 32 is a layer that mainly contains one of the elements α of the seed layer 40, and by having the same crystal orientation as the seed layer 40, when the columnar crystals of the one of the elements α contained in the seed layer 40 have an fcc structure, the orientation of the (111) plane or the (200) plane can be enhanced.

[0022] In addition, "mainly containing one element α" means that when the one element α is the most abundant element constituting the second underlayer 32, the content of the one element α is preferably 50 atomic % or more of the elements constituting the second underlayer 32, and also includes the case where it is 100 atomic % of the elements constituting the second underlayer 32.

[0023] The thickness of the second underlayer 32 is preferably within the range of 1 to 10 nm.

[0024] The third underlayer 33 is a layer primarily containing one of Ru, Cr, and Mo, and is preferentially alloyed with the other element β at the interface with the seed layer 40. This promotes phase separation between the one element α and the other element β, and when the columnar crystals of the one element α contained in the seed layer 40 have an fcc structure, the third underlayer 33 can enhance the orientation of the (111) plane or the (200) plane. The third underlayer 33 also has the effect of suppressing unintended diffusion of elements from layers on the non-magnetic substrate 10 side to the seed layer 40.

[0025] In addition, "mainly containing one of Ru, Cr, and Mo" means that when the most abundant element constituting the third underlayer 33 is one of Ru, Cr, and Mo, the content of any of Ru, Cr, and Mo is preferably 50 atomic % or more of the elements constituting the third underlayer 33, and includes the case where it is 100 atomic % of the elements constituting the third underlayer 33.

[0026] The thickness of the third underlayer 33 is preferably within the range of 1 to 10 nm.

[0027] The magnetic recording medium 1 preferably includes an intermediate layer 50 between the seed layer 40 and the magnetic recording layer 60, the intermediate layer 50 being a layer mainly containing Ru or MgO, and the magnetic recording layer 60 being a layer mainly containing a Co-Cr-Pt alloy containing Co, Cr, and Pt.

[0028] Incidentally, "mainly containing Ru or MgO" means that the most abundant element constituting the intermediate layer 50 is Ru or MgO, and the content of Ru or MgO is preferably 50 atomic % or more of the elements constituting the intermediate layer 50, and also includes the case where it accounts for 100% of the elements constituting the intermediate layer 50.

[0029] When an intermediate layer 50 containing mainly Ru or MgO is formed on the seed layer 40, the crystal grains constituting the intermediate layer 50 grow epitaxially as continuous columnar crystals in the thickness direction, while corresponding one-to-one with the crystal grains of the seed layer 40. When a magnetic recording layer 60 is formed on the intermediate layer 50, the crystal grains constituting the magnetic recording layer 60 grow epitaxially as continuous columnar crystals in the thickness direction, while corresponding one-to-one with the crystal grains of the intermediate layer 50.

[0030] In particular, if the crystal grains of one of the elements α constituting the seed layer 40 are made of Ag, Au, Al, or Pd with an fcc structure and (111) or (200) orientation, the intermediate layer 50 is made of Ru or MgO with an hcp structure and (200) orientation, and the magnetic recording layer 60 is made of a Co-Cr-Pt alloy with an hcp structure and (002) orientation, the epitaxially grown columnar crystals will be more uniform.

[0031] The magnetic recording layer 60 is primarily composed of a Co—Cr—Pt alloy and may further contain an oxide. The oxide is preferably any of Cr, Si, Ta, Al, Ti, Mg, Co, and B. Among these, TiO2, Cr2O3, SiO2, and B2O3 are particularly suitable. The magnetic recording layer 60 is also preferably made of a composite oxide containing two or more types of oxides. Among these, Cr2O3-SiO2, Cr2O3-TiO2, and Cr2O3-SiO2-TiO2 are particularly suitable.

[0032] The thickness of the magnetic recording layer 60 is preferably 5 to 20 nm. When the thickness of the magnetic recording layer 60 is 5 nm or more, sufficient reproduction output is obtained and deterioration of thermal fluctuation characteristics is suppressed. Furthermore, when the thickness of the magnetic recording layer 60 is 20 nm or less, enlargement of the magnetic grains in the magnetic recording layer 60 is suppressed, an increase in noise during recording and reproduction is suppressed, and deterioration of recording and reproduction characteristics, such as the S / N ratio and recording characteristics (OW), is suppressed, which is preferable.

[0033] The magnetic recording layer 60 may have a multilayer structure, or a nonmagnetic layer may be inserted between the magnetic recording layers 60 of the multilayer structure. It is preferable to use a material having an hcp structure as the nonmagnetic layer provided between the magnetic recording layers 60. For example, Ru, Ru alloy, CoCr alloy, and CoCrX1 alloy (X1 represents at least one or more elements selected from Pt, Ta, Zr, Re, Ru, Cu, Nb, Ni, Mn, Ge, Si, O, N, W, Mo, Ti, V, Zr, and B) can be suitably used.

[0034] Furthermore, it is preferable that the magnetic recording medium 1 has an intermediate layer 50 between the seed layer 40 and the magnetic recording layer 60, the intermediate layer 50 mainly containing an NaCl-type compound, and the magnetic recording layer 60 mainly containing magnetic grains having an L10 structure.

[0035] Incidentally, "mainly containing NaCl-type compounds" means that the most abundant element constituting the intermediate layer 50 is an NaCl-type compound, and the content of the NaCl-type compound is preferably 50 atomic % or more of the elements constituting the intermediate layer 50, and also includes the case where it is 100% of the elements constituting the intermediate layer 50.

[0036] Furthermore, "mainly containing magnetic grains having an L10 structure" means that the majority of the magnetic grains constituting the magnetic recording layer 60 are magnetic grains having an L10 structure, and the content of magnetic grains having an L10 structure is preferably 50 atomic % or more of the magnetic grains constituting the magnetic recording layer 60, and also includes the case where they account for 100% of the magnetic grains constituting the magnetic recording layer 60.

[0037] Examples of magnetic particles having an L10 structure include FePt alloy particles and CoPt alloy particles. Examples of NaCl-type compounds include MgO, TiO, NiO, TiN, TaN, HfN, NbN, ZrC, HfC, TaC, NbC, and TiC. These may be used alone or in combination.

[0038] When an intermediate layer 50 containing mainly an NaCl-type compound is formed on the seed layer 40, the crystal grains constituting the intermediate layer 50 grow epitaxially as continuous columnar crystals in the thickness direction, while corresponding one-to-one with the crystal grains of the seed layer 40. When a magnetic recording layer 60 is formed on the intermediate layer 50, the crystal grains constituting the magnetic recording layer 60 grow epitaxially as continuous columnar crystals in the thickness direction, while corresponding one-to-one with the crystal grains of the intermediate layer 50.

[0039] In particular, if the first underlayer 31 of the underlayer 30 mainly contains Ni with an fcc structure and (111) orientation, the α crystal grains constituting the seed layer 40 are any of Ag, Au, Al, and Pd with an fcc structure and (111) orientation, the intermediate layer 50 is Ru with a (200) orientation, and the magnetic recording layer 60 is an FePt alloy with an L10 structure and (001) orientation, the epitaxially grown columnar crystals will be more uniform. Furthermore, if the first underlayer 31 of the underlayer 30 is made of Cr with an fcc structure and (200) orientation, the crystal grains of α constituting the seed layer 40 are made of any of Ag, Au, Al, and Pd with an fcc structure and (200) orientation, the intermediate layer 50 is made of MgO, which is an NaCl-type compound and (200) oriented, and the magnetic recording layer 60 is made of an FePt alloy with an L10 structure and (001) orientation, the epitaxially grown columnar crystals will be more uniform. Among these, it is particularly preferable to use Ag as one of the elements α.

[0040] One or more elements selected from the group consisting of Al, Si, Ga, and Ge may be added to magnetic particles having an L10 structure. The amount of these elements added is preferably 2 to 20 mol %, and more preferably 2.5 to 10 mol %. Adding these elements in the above amounts improves the orientation of the (001) plane of the magnetic recording layer 60.

[0041] Furthermore, the magnetic recording layer 60 may have a granular structure by adding a grain boundary segregation material to the magnetic recording layer 60. This improves the orientation of the (001) plane of the magnetic recording layer 60. Examples of the grain boundary segregation material include nitrides such as VN, BN, SiN, and TiN, carbides such as C and VC, and borides such as BN, and two or more of these may be used in combination.

[0042] The thickness of the magnetic recording layer 60 is preferably 5 to 20 nm. When the thickness of the magnetic recording layer 60 is 5 nm or more, sufficient reproduction output can be obtained and deterioration of thermal fluctuation characteristics can be suppressed. Furthermore, when the thickness of the magnetic recording layer 60 is 20 nm or less, enlargement of the magnetic grains in the magnetic recording layer 60 can be suppressed, noise during recording and reproduction can be suppressed, and recording and reproduction characteristics such as the S / N ratio and recording characteristics (OW) can be maintained at a good level, which is preferable.

[0043] The magnetic recording layer 60 may have a multi-layer structure, or a non-magnetic layer may be inserted between the magnetic recording layers 60 of the multi-layer structure.

[0044] The other configurations will be described.

[0045] The non-magnetic substrate 10 may be a metal substrate made of a metal material such as aluminum or an aluminum alloy, or a non-metal substrate made of a non-metal material such as glass, ceramics, silicon, silicon carbide, or carbon. It is also possible to use a metal or non-metal substrate having a NiP layer or NiP alloy layer formed on the surface thereof by, for example, plating or sputtering.

[0046] Soft magnetic underlayer 20 is provided to increase the component of magnetic flux generated from the magnetic head that is perpendicular to the surface of non-magnetic substrate 10, and to more firmly fix the direction of magnetization of magnetic recording layer 60, in which information is recorded, in a direction perpendicular to non-magnetic substrate 10. This effect is particularly noticeable when a single-pole head for perpendicular recording is used as the magnetic head for recording and reproduction.

[0047] For the soft magnetic underlayer 20, for example, a soft magnetic material containing Fe and Ni or Co and having an amorphous or microcrystalline structure can be used. Examples of soft magnetic materials include CoFe-based alloys (such as CoFeTaZr and CoFeZrNb), FeCo-based alloys (such as FeCo and FeCoV), FeNi-based alloys (such as FeNi, FeNiMo, FeNiCr, and FeNiSi), FeAl-based alloys (such as FeAl, FeAlSi, FeAlSiCr, FeAlSiTiRu, and FeAlO), FeCr-based alloys (such as FeCr, FeCrTi, and FeCrCu), FeTa-based alloys (such as FeTa, FeTaC, and FeTaN), FeMg-based alloys (such as FeMgO), FeZr-based alloys (such as FeZrN), FeC-based alloys, FeN-based alloys, FeSi-based alloys, FeP-based alloys, FeNb-based alloys, FeHf-based alloys, and FeB-based alloys.

[0048] The soft magnetic underlayer 20 is composed of two soft magnetic films, and preferably has a Ru film between the two soft magnetic films. By adjusting the thickness of the Ru film to within the range of 0.4 to 1.0 nm or 1.6 to 2.6 nm, the two soft magnetic films form an AFC structure. By having such an AFC structure, the soft magnetic underlayer 20 can suppress so-called spike noise.

[0049] The protective layer 70 suppresses corrosion of the magnetic recording layer 60 and also suppresses damage to the surface of the magnetic recording medium 1 when a magnetic head comes into contact with the magnetic recording medium 1. The protective layer 70 can be made of a material that has conventionally been used as a protective layer, and for example, a material containing C can be used.

[0050] The thickness of the protective layer 70 is preferably 1 to 10 nm in order to reduce the distance between the head and the magnetic recording medium 1 and to achieve high recording density of the magnetic recording medium 1.

[0051] The lubricating layer 80 is preferably formed using a lubricant such as perfluoropolyether, fluorinated alcohol, or fluorinated carboxylic acid.

[0052] (Magnetic recording and reproducing device) A magnetic storage device including the magnetic recording medium according to this embodiment will be described. The magnetic storage device according to this embodiment is not particularly limited in form as long as it includes the magnetic recording medium according to this embodiment.

[0053] 2 is a perspective view showing an example of a magnetic recording and reproducing device that uses the magnetic recording medium according to this embodiment. As shown in FIG. 2, the magnetic recording and reproducing device 100 includes a perpendicular magnetic recording medium 101, a medium drive unit 102 that rotates the perpendicular magnetic recording medium 101, a magnetic head 103 that records and reproduces information on the perpendicular magnetic recording medium 101, a head drive unit 104 that moves the magnetic head 103 relative to the perpendicular magnetic recording medium 101, and a recording and reproducing signal processing system 105. The perpendicular magnetic recording medium 101 is the magnetic recording medium 1 shown in FIG. 1 above. The recording and reproducing signal processing system 105 processes data input from an external device and sends a recording signal to the magnetic head 103, and processes a reproduction signal from the magnetic head 103 and sends the data to the outside.

[0054] In the magnetic recording and reproducing device 100, the magnetic recording medium 1 can have even better recording characteristics (OW), and therefore the magnetic recording and reproducing device 100 can have excellent high-density recording.

[0055] Although the embodiments have been described above, they are presented as examples and the present invention is not limited to the above embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, modifications, etc. can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as set forth in the claims. [Example]

[0056] Hereinafter, the present embodiment will be described in more detail with reference to examples, but the present embodiment is not limited to these examples.

[0057] Example 1 In Example 1, a cleaned glass substrate (manufactured by HOYA Corporation, outer diameter 3.5 inches) was placed in the chamber of a film forming apparatus (C-3010 manufactured by ANELVA Corporation) and the ultimate vacuum was 1×10 -5 The deposition chamber was evacuated to a vacuum of 10 Pa. Then, a 10 nm thick adhesion layer was formed on a glass substrate by DC magnetron sputtering using a Cr target. A 25 nm thick soft magnetic underlayer was formed on this adhesion layer by DC magnetron sputtering using a Co-20Fe-5Zr-5Ta {Fe content 20 atomic %, Zr content 5 atomic %, Ta content 5 atomic %, balance Co} target at a substrate temperature of 100°C or less. A 0.7 nm thick Ru layer was then formed on the soft magnetic underlayer by DC magnetron sputtering, and a 25 nm thick soft magnetic underlayer was then formed again by DC magnetron sputtering using a Co-20Fe-5Zr-5Ta target.

[0058] Next, a first underlayer having a thickness of 5 nm was formed on the soft magnetic underlayer by DC magnetron sputtering using a target of 82Ni-3W-15Fe {W content 3 atomic %, Fe content 15%, balance Ni}.

[0059] Next, a second underlayer having a thickness of 2 nm was formed on the first underlayer by DC magnetron sputtering using an Ag target.

[0060] Next, a third underlayer having a thickness of 0.3 nm was formed on the second underlayer by DC magnetron sputtering using a Ru target.

[0061] Next, a seed layer having a thickness of 5 nm was formed on the third underlayer by RF sputtering using a 40Ag-60Ge target.

[0062] Next, a 20 nm thick intermediate layer was formed using a Ru target. The sputtering pressure was 0.8 Pa to form a 10 nm thick Ru film, and then the sputtering pressure was 1.5 Pa to form a 10 nm thick Ru film.

[0063] Next, a three-layer magnetic recording layer was deposited on the intermediate layer by DC magnetron sputtering. Specifically, a 9-nm-thick first magnetic recording layer was deposited using a target of 91(Co15Cr16Pt)-6(SiO2)-3(TiO2) (Cr content 15 atomic %, Pt content 16 atomic %, the remainder Co alloy 91 mol %, SiO2 oxide 6 mol %, TiO2 oxide 3 mol %). The sputtering pressure was 2 Pa.

[0064] Next, a 6-nm-thick second magnetic recording layer was deposited on the first magnetic recording layer using a target of 92(Co11Cr18Pt)-5(SiO2)-3(TiO2) (11 atomic % Cr, 18 atomic % Pt, and the remainder being 92 mol % Co alloy, 5 mol % SiO2 oxide, and 3 mol % TiO2 oxide). The sputtering pressure was 2 Pa.

[0065] Next, a third magnetic recording layer with a thickness of 7 nm was deposited on the second magnetic recording layer using a target of Co20Cr14Pt3B (Cr content 20 atomic %, Pt content 14 atomic %, B content 3 atomic %, balance Co) at a sputtering pressure of 0.6 Pa.

[0066] Next, a protective layer having a thickness of 3 nm was formed on the third magnetic recording layer by a CVD method, and then a lubricating film made of perfluoropolyether was formed to a thickness of 1 nm by a dipping method, thereby obtaining the magnetic recording medium of Example 1. The configuration of each layer of the produced magnetic recording medium is shown in Tables 1 to 3.

[0067] The magnetic recording media thus produced were observed using a TEM to measure the average particle size D of the magnetic particles constituting the first to third magnetic recording layers, and the particle size dispersion σ / D normalized by this average particle size D. The c-axis orientation dispersion (Δθ50) of the intermediate layer was also evaluated using X-ray diffraction. Δθ50 was measured at the diffraction peak of the (002) plane, regardless of whether the intermediate layer was composed of Ru or MgO. The evaluation results are shown in Tables 2 and 3. The smaller the values ​​of the average particle size D, particle size dispersion σ / D, and c-axis orientation dispersion Δθ50, the finer the magnetic particles and the higher the orientation.

[0068] (Examples 2 to 11, Comparative Examples 1 to 7) Magnetic recording media were fabricated in the same manner as in Example 1, but the manufacturing conditions for the first to third underlayers, seed layer, intermediate layer, and magnetic recording layer were changed as shown in Tables 1 to 3. In Example 6, the substrate temperature was set to 250°C when depositing the intermediate layer made of MgO, and to 450°C when depositing the magnetic recording layer made of FePt. The evaluation results are shown in Tables 2 and 3.

[0069] [Table 1]

[0070] [Table 2]

[0071] [Table 3]

[0072] As can be seen from Tables 2 and 3, in each example, the c-axis orientation dispersion Δθ50 of the intermediate layer was 5.1 or less, the average grain size D of the magnetic grains in the magnetic recording layer was 8.2 nm or less, and the grain size dispersion σ / D was 15% or less, all of which were small values. On the other hand, in each comparative example, the c-axis orientation dispersion Δθ50 of the intermediate layer was 4.2 or more, and the grain size dispersion σ / D of the magnetic recording layer was 16 or more, all of which were high values.

[0073] Therefore, the seed layer of the magnetic recording medium contains two elements, the phase of one element has columnar crystals with an fcc structure, and the phase of the other element has an amorphous structure, the first underlayer mainly contains one of Ru, Cr, and Ni, the second underlayer mainly contains one element, and the third underlayer mainly contains one of Ru, Cr, and Mo.It has been confirmed that this makes the magnetic grains contained in the magnetic recording layer finer and improves perpendicular orientation.Therefore, the magnetic recording medium of each embodiment has a magnetic recording layer with a high recording density, and by using it in a magnetic storage device, it can be said that the magnetic storage device can have a high recording capacity. [Explanation of symbols]

[0074] 1. Magnetic recording media 10 Non-magnetic substrate 20 Soft magnetic underlayer 30 Base layer 31 First base layer 32 Second base layer 33 Third Underlayer 40 seed layer 50 Middle Class 60 Magnetic Recording Layer 70 protective layer 80 Lubricating layer 101 Perpendicular magnetic recording media 102 Media drive unit 103 Magnetic Head 104 Head drive unit 105 Recording / playback signal processing system

Claims

1. a base layer, a seed layer, and a magnetic recording layer provided in this order on a non-magnetic substrate; the seed layer includes two elements that are phase-separated from each other; On the other hand, the phase of element α has mainly columnar crystals with an fcc structure, The phase of the other element β has a predominantly amorphous structure, the underlayer includes, from the non-magnetic substrate side, a first underlayer, a second underlayer, and a third underlayer; the first underlayer mainly contains any one of Ru, Cr, and Ni; the second underlayer mainly contains the one element α, The magnetic recording medium, wherein the third underlayer mainly contains any one of Ru, Cr, and Mo.

2. the one element α is any one of Ag, Au, Al, and Pd, 2. The magnetic recording medium according to claim 1, wherein the other element β is either Ge or Si.

3. an intermediate layer between the seed layer and the magnetic recording layer; the intermediate layer is a layer mainly containing Ru, 3. The magnetic recording medium according to claim 1, wherein the magnetic recording layer is a layer containing mainly Co, Cr, and Pt.

4. an intermediate layer between the seed layer and the magnetic recording layer; the intermediate layer primarily comprises an NaCl-type compound; The magnetic recording layer is L1 ０ 3. The magnetic recording medium according to claim 1, which mainly comprises magnetic particles having a structure.

5. 3. A magnetic recording and reproducing device comprising the magnetic recording medium according to claim 1.

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