Abstract: A perpendicular magnetic recording medium is provided with a substrate, a soft magnetic back layer provided on a surface of the substrate, an orientation controlling underlayer provided on the soft magnetic back layer, and a recording layer provided above the orientation controlling underlayer and having axes of easy magnetization approximately perpendicular to the surface of the substrate. The recording layer is made of a ferromagnetic material having an hcp crystal structure. The orientation controlling underlayer is made of a nonmagnetic material having an fcc crystal structure and having NiCr or NiCu as a main component.

Abstract: A magnetic recording medium is disclosed that is able to increase a coercive force Hc of a recording layer and improve a signal-to-noise ratio of the recording layer without degradation of a thermal fluctuation resistance of the recording layer, and enables high density recording. The magnetic recording medium includes a substrate, a seed layer formed from a crystalline material, a grain diameter control layer, an underlying layer, and a recording layer. The grain diameter control layer is formed from an Ag film or a W film, to be a dispersed film or a continuous film on the seed layer. The grain diameter control layer acts as growing nuclei of the underlying layer formed thereon, and controls crystal grain diameters of the underlying layer.

Abstract: A magnetic recording medium includes a substrate, an AlFe-based alloy layer provided above the substrate, an underlayer provided on the AlFe-based alloy layer, and a recording layer provided on the underlayer and magnetized in a predetermined recording direction when being recorded with information. The substrate has a textured surface having grooves formed approximately along the recording direction.

Abstract: This invention relates to a magnetic recording medium that magnetically records information, and the like. The magnetic recording medium enhances write-reception performance by reducing the distance between a recording layer and a backing layer while maintaining low noise performance. The magnetic recording medium has a non-magnetic substrate, a backing layer formed on the non-magnetic substrate, an underlayer formed on the backing layer, an intermediate layer formed on the underlayer, and a recording layer which is formed on the intermediate layer and which is a perpendicular magnetic anisotropy. The intermediate layer includes two or more layers which are formed as film layers such that an upper layer of the two or more layers has a thicker film thickness and a higher gas pressure at which the layer is formed in comparison to a layer under the upper layer.

Abstract: A magnetic recording medium which is thermally stable and produces low media noise. By providing a plurality of intermediate layers made of a CoCr alloy of which saturation magnetic flux densities are controlled within a predetermined range, the magnetic recording medium simultaneously realizes both a high S/Nm and thermal stability.

Abstract: A perpendicular magnetic recording medium is provided with a substrate, a soft magnetic back layer provided on a surface of the substrate, an orientation controlling underlayer provided on the soft magnetic back layer, and a recording layer provided above the orientation controlling underlayer and having axes of easy magnetization approximately perpendicular to the surface of the substrate. The recording layer is made of a ferromagnetic material having an hcp crystal structure. The orientation controlling underlayer is made of a nonmagnetic material having an fcc crystal structure and having NiCr or NiCu as a main component.

Abstract: A magnetic recording medium includes: a substrate; a underlayer, produced on the substrate, comprising Cr or Cr alloy: a first magnetic layer, produced on the underlayer, comprising CoCr or CoCr alloy; an RuB alloy layer produced on the first magnetic layer; and a second magnetic layer, produced on the RuB alloy layer, comprising CoCrPt or CoCrPt alloy, and coupled with the first magnetic layer in an antiferromagnetic exchange coupling manner, wherein: the RuB alloy layer comprises RuB having an hcp structure or RuB alloy having Rub as a chief ingredient, and also, epitaxially grows on a surface of the first magnetic layer; and the second magnetic layer epitaxially grows on a surface of the RuB alloy layer.

Abstract: A magnetic recording medium is disclosed that includes a substrate, a base layer provided on the substrate, and a recording layer provided on the base layer. The recording layer includes a first magnetic layer and a second magnetic layer from the base layer side. Each of the first magnetic layer and the second magnetic layer includes a ferromagnetic material composed mainly of CoCrPtB. The first magnetic layer contains more B and less Cr than the second magnetic layer on an atomic percentage basis.

Abstract: A polycrystalline structure film is formed on the surface of a substrate in a magnetic recording medium. The second magnetic layer has a saturation magnetic flux density Bs larger than that of the first magnetic layer in the polycrystalline structure film, so that the magnetic layer for recordation ensures a larger residual magnetization Br, as compared with the case where the first magnetic layer solely forms a magnetic layer for recordation. A sufficient magnitude of product tBr of thickness t and residual magnetization Br can be obtained even if the thickness of the overall magnetic layer for recordation is reduced. A sufficient magnitude of magnetic outputs can be ensured. A reduced thickness of the magnetic layer serves to minimize the magnetic crystal grains in the first and second magnetic layers. A higher resolution of recordation and reproduction can be obtained.

Abstract: A magnetic recording medium is disclosed that is able to increase a coercive force Hc of a recording layer and improve a signal-to-noise ratio of the recording layer without degradation of a thermal fluctuation resistance of the recording layer, and enables high density recording. The magnetic recording medium includes a substrate, a seed layer formed from a crystalline material, a grain diameter control layer, an underlying layer, and a recording layer. The grain diameter control layer is formed from an Ag film or a W film, to be a dispersed film or a continuous film on the seed layer. The grain diameter control layer acts as growing nuclei of the underlying layer formed thereon, and controls crystal grain diameters of the underlying layer.

Abstract: A magnetic recording medium includes a substrate, an AlFe-based alloy layer provided above the substrate, an underlayer provided on the AlFe-based alloy layer, and a recording layer provided on the underlayer and magnetized in a predetermined recording direction when being recorded with information. The substrate has a textured surface having grooves formed approximately along the recording direction.

Abstract: A magnetic recording medium comprises a non-magnetic substrate having deposited thereon, in sequence, at least one underlayer formed of Cr or a Cr-based alloy, at least one intermediate layer formed of a Co-based alloy and at least one magnetic recording layer formed of a CoCr-based alloy, and the underlayer and/or the intermediate layer is a thin film formed by a sputtering method in the presence of krypton gas and/or xenon gas. A production method of the magnetic recording medium and a magnetic disc device using the magnetic recording medium are also disclosed.

Abstract: A magnetic recording medium which is thermally stable and produces low media noise. By providing a plurality of intermediate layers made of a CoCr alloy of which saturation magnetic flux densities are controlled within a predetermined range, the magnetic recording medium simultaneously realizes both a high S/Nm and thermal stability.

Abstract: A magnetic recording medium including a ferromagnetic layer made of a Co-based alloy material, a nonmagnetic coupling layer formed on the ferromagnetic layer and made of Ru or a Ru-based alloy material, and a magnetic recording layer formed on the nonmagnetic coupling layer and made of a Co-based alloy material. The nonmagnetic coupling layer is formed by sputtering in an atmosphere of Ar—N2 mixed gas, so that the nonmagnetic coupling layer contains nitrogen. The partial pressure of nitrogen during the sputtering is set in the range of 6.7×10?3 to 3.7×10?2 Pa.

Abstract: A magnetic recording medium which is thermally stable and produces low media noise. By providing a plurality of intermediate layers made of a CoCr alloy of which saturation magnetic flux densities are controlled within a predetermined range, the magnetic recording medium simultaneously realizes both a high S/Nm and thermal stability.

Abstract: A polycrystalline structure film is formed on the surface of a substrate in a magnetic recording medium. The second magnetic layer has a saturation magnetic flux density Bs larger than that of the first magnetic layer in the polycrystalline structure film, so that the magnetic layer for recordation ensures a larger residual magnetization Br, as compared with the case where the first magnetic layer solely forms a magnetic layer for recordation. A sufficient magnitude of product tBr of thickness t and residual magnetization Br can be obtained even if the thickness of the overall magnetic layer for recordation is reduced. A sufficient magnitude of magnetic outputs can be ensured. A reduced thickness of the magnetic layer serves to minimize the magnetic crystal grains in the first and second magnetic layers. A higher resolution of recordation and reproduction can be obtained.

Abstract: A magnetic recording medium includes a substrate; and a recording layer and a protection layer which are provided upward of the substrate, wherein the recording layer includes a magnetic layer; and the magnetic layer includes an additive chemical element selected from a CoCrPt group alloy and a group comprising and chemical elements in which a standard electrode electric potential is negative and platinum group chemical elements other than Pt.

Abstract: A magnetic recording medium which is thermally stable and produces low media noise. By providing a plurality of intermediate layers made of a CoCr alloy of which saturation magnetic flux densities are controlled within a predetermined range, the magnetic recording medium simultaneously realizes both a high S/Nm and thermal stability.