Abstract: A medium having high medium S/N and excellent corrosion resistance is achieved. In one embodiment, an adhesion layer, a soft magnetic layer, an intermediate layer, a magnetic recording layer, and a protective layer are deposited, in order, on a substrate. The soft magnetic underlayer consists at least of two soft magnetic layers, the first soft magnetic layer formed on the recording layer side being composed of an amorphous alloy containing 85 at. % or less of Co, and the second soft magnetic layer formed on the substrate side being composed of an alloy containing more than 85 at. % of Co.

Abstract: According to one embodiment, a PMRM includes a substrate, a soft magnetic underlayer above the substrate, an underlayer above the soft magnetic underlayer, an oxide-containing magnetic layer above the underlayer, and a ferromagnetic layer above the magnetic layer having no oxides. The underlayer controls orientation and segregation of the magnetic layer. The oxide-containing magnetic layer comprises at least two or more magnetic layers, a Cr concentration of the magnetic layer adjacent to the ferromagnetic metal layer is between about 23 at. % and about 32 at. %, and a difference between the Cr concentration of the magnetic layer adjacent to the ferromagnetic metal layer and a magnetic layer having a lowest Cr concentration among the at least three magnetic layers is less than about 25 at. %, the magnetic layer with a lowest Cr concentration has a granular structure, and a nucleation field is greater than about 159.2 kA/m.

Abstract: According to one embodiment, a perpendicular magnetic recording medium includes a soft magnetic underlayer having an amorphous structure or a microcrystalline structure, a first seed layer comprised of a magnetic material having an fcc crystal structure including a CoFe alloy formed on a substrate side, and a second seed layer formed on the first seed layer, the second seed layer comprised of a nonmagnetic material having an fcc crystal structure including a NiW alloy. The medium also includes an intermediate layer comprised of Ru or an alloy thereof, a magnetic recording layer, and a protective layer, wherein the layers are sequentially stacked on a substrate in the foregoing order and the protective layer is closer to the substrate than the soft magnetic underlayer. Other embodiments of magnetic recording media, and methods of fabrication, are also described.

Abstract: According to one embodiment, a perpendicular magnetic recording medium includes at least one soft magnetic underlayer above a substrate, a seed layer above the at least one soft magnetic underlayer, an intermediate layer above the seed layer, a magnetic recording layer above the intermediate layer, and an overcoat layer above the magnetic recording layer, wherein the seed layer includes a second seed layer above a first seed layer. In another embodiment, the seed layer is a multilayered structure of at least two cycles of a unit of layered film which includes a first seed layer and a second seed layer. The first seed layer includes a non-magnetic alloy having a Face-Centered-Cubic (FCC) structure, and the second seed layer includes a soft magnetic alloy having a FCC structure. Other structures are also disclosed, according to more embodiments.

Abstract: Embodiments of the present invention provide a perpendicular magnetic recording medium which does not cause medium noise to increase due to soft magnetic underlayers, is capable of easily controlling the thickness of a nonmagnetic layer disposed between soft magnetic underlayers, and capable of improving the corrosion resistance of the soft magnetic underlayers. According to one embodiment, in a perpendicular magnetic recording medium, an adhesion layer is formed on a substrate, a soft magnetic underlayer is formed on the adhesion layer, a seed layer and an intermediate layer are formed above the soft magnetic underlayer, and a perpendicular layer is formed on the intermediate layer.

Abstract: Embodiments of the invention provide a perpendicular magnetic recording medium improved for fly ability, high in read signal quality, and capable of suppressing magnetic decay of recorded magnetization to be caused by stray fields. In one embodiment, a perpendicular recording layer is formed over a substrate with a soft magnetic underlayer therebetween, then an amorphous or nano-crystalline layer is formed between the substrate and the soft magnetic underlayer. The soft magnetic underlayer includes first and second amorphous soft magnetic layers, as well as a nonmagnetic layer formed between those first and second amorphous soft magnetic layers. The first and second amorphous soft magnetic layers are given uniaxial anisotropy in the radial direction of the substrate respectively and coupled with each other antiferromagnetically.

Abstract: Embodiments of the invention provide a perpendicular magnetic recording medium improved for fly ability, high in read signal quality, and capable of suppressing magnetic decay of recorded magnetization to be caused by stray fields. In one embodiment, a perpendicular recording layer is formed over a substrate with a soft magnetic underlayer therebetween, then an amorphous or nano-crystalline layer is formed between the substrate and the soft magnetic underlayer. The soft magnetic underlayer includes first and second amorphous soft magnetic layers, as well as a nonmagnetic layer formed between those first and second amorphous soft magnetic layers. The first and second amorphous soft magnetic layers are given uniaxial anisotropy in the radial direction of the substrate respectively and coupled with each other antiferromagnetically.

Abstract: Embodiments in accordance with the present invention help to obtain a perpendicular magnetic recording medium having a granular structure, excellent recording/reproducing properties, and excellent durability. According to one embodiment, a recording layer includes a layer which has crystal grains mainly composed of cobalt and crystal grain boundaries mainly composed of the oxide; the oxygen content of the recoding layer is changed in the film thickness direction; the oxygen content in the area in the vicinity of the interface between the recording layer and the intermediate layer is made lower than the oxygen content in the area in the vicinity of the center of the recording layer; and the oxygen content in the area in the vicinity of the interface between the recording layer and the protective layer is made lower than the oxygen content in the area in the vicinity of the center of the recording layer.

Abstract: Embodiments of the invention provide a perpendicular magnetic recording medium improved for fly ability, high in read signal quality, and capable of suppressing magnetic decay of recorded magnetization to be caused by stray fields. In one embodiment, a perpendicular recording layer is formed over a substrate with a soft magnetic underlayer therebetween, then an amorphous or nano-crystalline layer is formed between the substrate and the soft magnetic underlayer. The soft magnetic underlayer includes first and second amorphous soft magnetic layers, as well as a nonmagnetic layer formed between those first and second amorphous soft magnetic layers. The first and second amorphous soft magnetic layers are given uniaxial anisotropy in the radial direction of the substrate respectively and coupled with each other antiferromagnetically.

Abstract: According to one embodiment, a PMRM includes a substrate, a soft magnetic underlayer above the substrate, an underlayer above the soft magnetic underlayer, an oxide-containing magnetic layer above the underlayer, and a ferromagnetic layer above the magnetic layer having no oxides. The underlayer controls orientation and segregation of the magnetic layer. The oxide-containing magnetic layer comprises at least two or more magnetic layers, a Cr concentration of the magnetic layer adjacent to the ferromagnetic metal layer is between about 23 at. % and about 32 at. %, and a difference between the Cr concentration of the magnetic layer adjacent to the ferromagnetic metal layer and a magnetic layer having a lowest Cr concentration among the at least three magnetic layers is less than about 25 at. %, the magnetic layer with a lowest Cr concentration has a granular structure, and a nucleation field is greater than about 159.2 kA/m.

Abstract: According to one embodiment, a perpendicular magnetic recording medium includes at least one soft magnetic underlayer above a substrate, a seed layer above the at least one soft magnetic underlayer, an intermediate layer above the seed layer, a magnetic recording layer above the intermediate layer, and an overcoat layer above the magnetic recording layer, wherein the seed layer includes a second seed layer above a first seed layer. In another embodiment, the seed layer is a multilayered structure of at least two cycles of a unit of layered film which includes a first seed layer and a second seed layer. The first seed layer includes a non-magnetic alloy having a Face-Centered-Cubic (FCC) structure, and the second seed layer includes a soft magnetic alloy having a FCC structure. Other structures are also disclosed, according to more embodiments.

Abstract: According to one embodiment, a perpendicular magnetic recording medium includes a soft magnetic underlayer having an amorphous structure or a microcrystalline structure, a first seed layer comprised of a magnetic material having an fcc crystal structure including a CoFe alloy formed on a substrate side, and a second seed layer formed on the first seed layer, the second seed layer comprised of a nonmagnetic material having an fcc crystal structure including a NiW alloy. The medium also includes an intermediate layer comprised of Ru or an alloy thereof, a magnetic recording layer, and a protective layer, wherein the layers are sequentially stacked on a substrate in the foregoing order and the protective layer is closer to the substrate than the soft magnetic underlayer. Other embodiments of magnetic recording media, and methods of fabrication, are also described.

Abstract: Embodiments of the present invention help to provide an excellent perpendicular recording medium of high medium signal-to-noise (S/N) and with suppressed blurring in writing. According to one embodiment, a perpendicular recording layer is provided by way of a negative magnetic strain soft-magnetic underlayer above a substrate applied with texturing in the circumferential direction. The soft-magnetic underlayer has a first soft magnetic layer, a second soft magnetic layer and a nonmagnetic magnetic layer formed between the first soft magnetic layer and the second soft magnetic layer in which the first soft magnetic layer and the second soft magnetic layer are antiferromagnetically coupled to each other and the easy magnetization axis is directed in the radial direction.

Abstract: Embodiments of the invention relate to easily achieving a perpendicular magnetic recording medium with high reliability and a magnetic recording apparatus with high recording density by improving the magnetic properties and surface smoothness of the soft magnetic underlayer and, moreover, enhancing adhesion with the substrate.

Abstract: Embodiments of the invention provide a medium which provides high media S/N and good corrosion resistance. According to one embodiment, in a perpendicular magnetic recording medium at least comprising a soft-magnetic underlayer, a seed layer, an intermediate layer, a magnetic recording layer and an overcoat layer which are stacked over a substrate in order, the magnetic recording layer has a granular structure which consists of many columnar grains of CoCrPt alloy and a grain boundary layer containing an oxide, the seed layer is made of TaNi alloy or TaTi alloy and the intermediate layer is made of Ru or Ru alloy which contains about 80 at. % Ru or more.

Abstract: Embodiments of the invention are directed to a medium which provides high media S/N and good corrosion resistance. According to one embodiment, in a perpendicular magnetic recording medium at least comprising a soft-magnetic underlayer, a seed layer, an intermediate layer, a magnetic recording layer and an overcoat layer which are stacked over a substrate in order, the magnetic recording layer has a granular structure which includes many columnar grains of CoCrPt alloy and a grain boundary layer containing an oxide, the seed layer is made of TaNi alloy or TaTi alloy and the intermediate layer is made of Ru or Ru alloy which contains 80 at. % Ru or more.

Abstract: Embodiments of the present invention help to provide an excellent perpendicular recording medium of high medium signal-to-noise (S/N) and with suppressed blurring in writing. According to one embodiment, a perpendicular recording layer is provided by way of a negative magnetic strain soft-magnetic underlayer above a substrate applied with texturing in the circumferential direction. The soft-magnetic underlayer has a first soft magnetic layer, a second soft magnetic layer and a nonmagnetic magnetic layer formed between the first soft magnetic layer and the second soft magnetic layer in which the first soft magnetic layer and the second soft magnetic layer are antiferromagnetically coupled to each other and the easy magnetization axis is directed in the radial direction.

Abstract: Embodiments of the present invention provide a perpendicular magnetic recording medium which does not cause medium noise to increase due to soft magnetic underlayers, is capable of easily controlling the thickness of a nonmagnetic layer disposed between soft magnetic underlayers, and capable of improving the corrosion resistance of the soft magnetic underlayers. According to one embodiment, in a perpendicular magnetic recording medium, an adhesion layer is formed on a substrate, a soft magnetic underlayer is formed on the adhesion layer, a seed layer and an intermediate layer are formed above the soft magnetic underlayer, and a perpendicular layer is formed on the intermediate layer.

Abstract: Embodiments in accordance with the present invention help to obtain a perpendicular magnetic recording medium having a granular structure, excellent recording/reproducing properties, and excellent durability. According to one embodiment, a recording layer includes a layer which has crystal grains mainly composed of cobalt and crystal grain boundaries mainly composed of the oxide; the oxygen content of the recoding layer is changed in the film thickness direction; the oxygen content in the area in the vicinity of the interface between the recording layer and the intermediate layer is made lower than the oxygen content in the area in the vicinity of the center of the recording layer; and the oxygen content in the area in the vicinity of the interface between the recording layer and the protective layer is made lower than the oxygen content in the area in the vicinity of the center of the recording layer.

Abstract: Embodiments of the present invention improve the production efficiency of a perpendicular recording medium while ensuring the scratch resistance thereof. In order to realize high production stability in the high speed production of perpendicular recording media, a target is not provided with a texture of a low melting point or the ratio thereof is decreased. Thus according to one embodiment of the present invention, upon forming a layer having an element of a low melting point in the constituent layers of a perpendicular recording medium, a target can be made using an alloy powder previously formed of an intermetallic compound having a melting point higher than 660° C., thereby preventing thermal deformation.