Abstract: An anti-reflective film-attached transparent substrate includes: a transparent substrate including two major surfaces; and a diffusion layer and an anti-reflective film on one major surface of the transparent substrate, which are provided in this order. (A) A luminous reflectance SCI Y of an outermost surface of the anti-reflective film-attached transparent substrate is 1% or lower. (B) The anti-reflective film has a lamination structure in which at least two dielectric layers having different refractive indices are laminated. (C) A ratio (SCE Y)/(SCI Y) of a diffuse reflectance SCE Y of the outermost surface of the anti-reflective film-attached transparent substrate to the luminous reflectance SCI Y of the outermost surface of the anti-reflective film-attached transparent substrate is 0.15 or higher.

Abstract: An optical filter including: a substrate; and a dielectric multilayer film laid on or above at least one major surface of the substrate as an outermost layer, in which: the dielectric multilayer film is a laminate including a low refractive index film and a high refractive index film laid on each other; the low refractive index film or the high refractive index film satisfies the spectral characteristics (i-1) and (i-2); the optical filter satisfies all of the spectral characteristics (ii-1) to (ii-3); and the optical filter has a nanoindentation hardness of 5.5 GPa or higher when a measurement load is 1 mN.

Abstract: An optical filter including: a substrate; and a dielectric multilayer film laid on or above at least one major surface of the substrate as an outermost layer, in which: the dielectric multilayer film is a laminate including a low refractive index film and a plurality of high refractive index films laid on each other; the dielectric multilayer film comprises four or more high refractive index films that are 15 nm or smaller in thickness; the high refractive index films have a minimum thickness of 1.5 to 5 nm; the high refractive index films have a minimum thickness of 100 nm or smaller; the high refractive index films satisfy the following spectral characteristics (i-1) and (i-2); and the optical filter satisfies all of the following spectral characteristics (ii-1) to (ii-4).

Abstract: An optical filter includes a substrate and a dielectric multilayer film laid as an outermost layer on at least one major surface of the substrate. The dielectric multilayer film includes a low-refractive index film and a high-refractive index film provided alternately. At least one film selected from the group consisting of the low-refractive index film and the high-refractive index film satisfies the following optical characteristics (i-1) and (i-2A): (i-1) an extinction coefficient k600 at a wavelength of 600 nm is 0.12 or larger; and (i-2A) a minimum extinction coefficient k1530-1570MIN in a wavelength range of 1530 to 1570 nm is 0.01 or smaller; and the optical filter satisfies the following optical characteristic (ii-1A): (ii-1A) light in a wavelength range of 400 to 680 nm is blocked and light in the wavelength range of 1530 to 1570 nm is transmitted.

Abstract: A magnetic recording medium may have a stacked structure including a first soft magnetic layer, an orientation control layer, a lower recording layer, an intermediate layer, and an upper recording layer that are sequentially stacked, and a second soft magnetic layer provided between the lower recording layer and the intermediate layer.

Abstract: A magnetic recording medium may include a stacked structure of orientation control, lower recording, intermediate, and upper recording layers. The lower recording layer has a coercivity higher than that of the upper recording layer. The lower recording layer includes a first layer with a granular structure that includes magnetic particles including Co, Cr, and Pt, and an oxide covering a periphery of the magnetic particles, and a second layer with a non-granular structure that includes magnetic particles including Co, Cr, and Pt. The lower recording layer includes columnar crystals continuous with crystal particles forming the orientation control layer in a stacking direction of the stacked structure.

Abstract: A magnetic recording medium may include an orientation control layer, a lower recording layer, an intermediate layer, and an upper recording layer that are stacked. The lower recording layer may have a coercivity higher than that of the upper recording layer, and the intermediate layer may include a layer including a magnetic material and having a saturation magnetization of 50 emu/cc or higher. The upper recording layer may include columnar crystals continuous with crystal particles forming the intermediate layer in a direction in which the layers are stacked.

Abstract: A servo information recording method continuously records servo information in a radial direction of a magnetic disk on a plurality of concentric tracks or on a single spiral track of a first recording layer that forms a magnetic layer of the magnetic disk together with a second recording layer to which data are recorded and from which data are reproduced, wherein the first recording layer has a coercivity higher than that of the second recording layer, and partially overlaps two mutually adjacent tracks when continuously recording the servo information on an entire surface of the first recording layer.

Abstract: A servo information recording method continuously records servo information in a radial direction of a magnetic disk on a plurality of concentric tracks or on a single spiral track of a first recording layer that forms a magnetic layer of the magnetic disk together with a second recording layer to which data are recorded and from which data are reproduced, wherein the first recording layer has a coercivity higher than that of the second recording layer, and partially overlaps two mutually adjacent tracks when continuously recording the servo information on an entire surface of the first recording layer.

Abstract: A magnetic recording medium may include a stacked structure of orientation control, lower recording, intermediate, and upper recording layers. The lower recording layer has a coercivity higher than that of the upper recording layer. The lower recording layer includes a first layer with a granular structure that includes magnetic particles including Co, Cr, and Pt, and an oxide covering a periphery of the magnetic particles, and a second layer with a non-granular structure that includes magnetic particles including Co, Cr, and Pt. The lower recording layer includes columnar crystals continuous with crystal particles forming the orientation control layer in a stacking direction of the stacked structure.

Abstract: A magnetic recording medium may have a stacked structure including a first soft magnetic layer, an orientation control layer, a lower recording layer, an intermediate layer, and an upper recording layer that are sequentially stacked, and a second soft magnetic layer provided between the lower recording layer and the intermediate layer.

Abstract: A perpendicular magnetic recording medium that is excellent in terms of electromagnetic conversion characteristics and can achieve the demand for the recording density growth, and a magnetic recording and reproducing apparatus provided with the perpendicular magnetic recording medium are provided. The perpendicular magnetic recording medium has at least a backing layer, an underlayer, an intermediate layer, and a perpendicular magnetic recording layer sequentially laminated on a non-magnetic substrate, in which the backing layer includes at least a soft magnetic film having an amorphous structure; the underlayer includes a first underlayer and a second underlayer laminated from the non-magnetic substrate side; the first underlayer is an fcc-structured alloy layer including an fcc-structured element and a bcc-structured element, the second underlayer includes a NiW alloy; and the intermediate layer includes Ru or a Ru alloy.

Abstract: A magnetic recording medium may include an orientation control layer, a lower recording layer, an intermediate layer, and an upper recording layer that are stacked. The lower recording layer may have a coercivity higher than that of the upper recording layer, and the intermediate layer may include a layer including a magnetic material and having a saturation magnetization of 50 emu/cc or higher. The upper recording layer may include columnar crystals continuous with crystal particles forming the intermediate layer in a direction in which the layers are stacked.

Abstract: Disclosed is a magnetic recording medium comprising a substrate, a magnetic recording layer formed on the substrate to record magnetic information, and a piezoelectric material disposed adjacent to the magnetic recording layer and capable of contracting and expanding. Preferably, piezoelectric members made of the piezoelectric material are formed in such a manner as to be spaced a predetermined distance apart from each other on the substrate in a direction crossing a track on the magnetic recording layer, and the magnetic recording layer is formed between the piezoelectric members. When subjected to laser light or ultraviolet radiation, the piezoelectric material contracts or expands at least in the direction crossing the track. The piezoelectric material is selected from the group consisting of lead lanthanum zirconate titanate, barium titanate, and potassium niobate.

Abstract: A perpendicular magnetic recording medium that is excellent in terms of electromagnetic conversion characteristics and can achieve the demand for the recording density growth, and a magnetic recording and reproducing apparatus provided with the perpendicular magnetic recording medium are provided. The perpendicular magnetic recording medium has at least a backing layer, an underlayer, an intermediate layer, and a perpendicular magnetic recording layer sequentially laminated on a non-magnetic substrate, in which the backing layer includes at least a soft magnetic film having an amorphous structure; the underlayer includes a first underlayer and a second underlayer laminated from the non-magnetic substrate side; the first underlayer is an fcc-structured alloy layer including an fcc-structured element and a bcc-structured element, the second underlayer includes a NiW alloy; and the intermediate layer includes Ru or a Ru alloy.

Abstract: Disclosed is a magnetic recording medium comprising a substrate, a magnetic recording layer formed on the substrate to record magnetic information, and a piezoelectric material disposed adjacent to the magnetic recording layer and capable of contracting and expanding. Preferably, piezoelectric members made of the piezoelectric material are formed in such a manner as to be spaced a predetermined distance apart from each other on the substrate in a direction crossing a track on the magnetic recording layer, and the magnetic recording layer is formed between the piezoelectric members. When subjected to laser light or ultraviolet radiation, the piezoelectric material contracts or expands at least in the direction crossing the track. The piezoelectric material is selected from the group consisting of lead lanthanum zirconate titanate, barium titanate, and potassium niobate.

Abstract: A method for manufacturing a magnetic recording medium including a nonmagnetic substrate, an intermediate layer over the nonmagnetic substrate, and a granular magnetic layer for recording information, disposed on the intermediate layer. The method includes sputtering a Co alloy, a Ti oxide, a Si oxide and a Co oxide simultaneously to form the granular magnetic layer containing Co alloy magnetic particles and an oxide magnetically separating the magnetic particles.

Abstract: One aspect of the embodiments utilizes, according to an aspect of the invention, a method of manufacturing a magnetic recording medium, which includes an intermediate layer and a granular magnetic layer as a recording layer sequentially formed on a non-magnetic substrate, includes the steps of forming the intermediate layer and forming the granular magnetic layer. The granular magnetic layer includes a plurality of magnetic particles made of a Co alloy and an oxide magnetically separating the plurality of magnetic particles by a sputtering method using a target. The target includes a Co alloy, one or more first oxides selected from a group of oxides of Si, Ti, Ta, Cr, W, and Nb, and a second oxide composed of a Co oxide.

Abstract: A method of producing a magnetic recording medium produces a medium having a magnetic recording layer disposed above a nonmagnetic intermediate layer, The nonmagnetic intermediate layer is formed by a sputtering using a target made of an oxide material. Oxygen gas or carbon dioxide gas is supplied during the sputtering in order to suppress a state where an oxygen supply becomes insufficient due to separation of oxygen atoms from the oxide material at a time of plasma generation.

Abstract: A magnetic recording medium used for a hard disc drive and the like, a method of manufacturing the same, and a magnetic storage device. The magnetic recording medium that includes a substrate, a first ferromagnetic layer formed on the substrate, a non-magnetic layer formed on the first ferromagnetic layer and including a ferromagnetic element and a second ferromagnetic layer formed on the non-magnetic layer, wherein the first ferromagnetic layer and the second ferromagnetic layer are magnetically coupled through the non-magnetic layer.