Wd Media (singapore) Pte. Ltd.

Hoya Corporation

Other

Hoya Magnetics Singapore Pte. Ltd.

Kenji Ayama

Teiichiro Umezawa

Masafumi Ishiyama

Tokichiro Sato

Junichi Horikawa

Takahiro Onoue

Hiroshi Tomiyasu

Tomotaka Yokoyama

Kazuaki Sakamoto

Kong Kim

Keiji Moroishi

A perpendicular magnetic recording medium includes a substrate, a soft magnetic layer, a pre-underlayer, an underlayer, and a main recording layer serving as a magnetic recording layer. The pre-underlayer contains seed crystal grains that serve as a base for crystal grains of the underlayer, and an addition substance that is added between the seed crystal grains and composed of an element having an atomic radius smaller than that of an element forming the seed crystal grains.

Perpendicular magnetic recording medium and method of manufacturing the same

A perpendicular magnetic recording medium of the invention is characterized by having, on a disk substrate, a soft magnetic layer, a magnetic recording layer, a continuous layermagnetically continuous in the in-plane direction of the substrate, a blocking layerfor blocking shock imposed on the continuous layer, and a medium protective layercontaining carbon formed on the blocking layer.

Perpendicular magnetic recording medium and manufacturing method of the same

An object of the present invention is to provide a method of manufacturing a perpendicular magnetic recording medium () in which both of a coercive force Hc and reliability can be achieved at a higher level even with heating at the time of forming a medium protective layer () and to provide the perpendicular magnetic recording medium (). Thus, in a typical structure of the present invention, in the method of manufacturing the perpendicular magnetic recording medium () including at least a magnetic recording layer (), which is a ferromagnetic layer of a granular structure in which a non-magnetic grain boundary part is formed between crystal grains each grown in a columnar shape, and a medium protective layer () with carbon hydride as a main component in this order on a disk base (), the method includes a magnetic recording layer forming step of forming the magnetic recording layer () so that the grain boundary part contains oxides of a plurality of types and a medium protective layer forming step of forming the medium protective layer () in a state where the disk base () having the magnetic recording layer () formed thereon is heated at 160 to 200 degrees Celsius.

Method of manufacturing perpendicular magnetic recording medium and perpendicular magnetic recording medium

[Problems] To have a thin film suitably function even when the thickness of the thin film is reduced. [Means for Solving Problems] Provided is a method for manufacturing a magnetic recording medium by forming a thin film on a substrate (). The method is provided with a thin film forming step of forming the thin film by using a substance brought into the plasma state as a material. In the thin film forming step, the thin film is formed by using a material substance gathering means () for gathering the substance brought into the plasma state to the periphery of the substrate. The material substance gathering means () gathers the substance brought into the plasma state, for instance, to the periphery of the substrate () by generating a magnetic field at the periphery of the substrate ().

Magnetic recording medium manufacturing method and laminate manufacturing method

A vertical magnetic recording disc () includes a base (), a magnetic recording layer (), and a medium protection layer (). The magnetic recording layer () is a ferromagnetic layer having a granular structure where a granular portion is formed. The medium protection layer () contains nitrogen (N) atoms and carbon (C) atoms with a number ratio (N/C) in a range from 0.050 to 0.150. In a Raman spectrum obtained by exciting the medium protection layer () by argon ion laser light of wavelength 514.5 nm, from which a fluorescence is removed, the peak ratio Dh/Gh is in a range from 0.70 to 0.95, when a D peak Dh appearing in the vicinity of 1350 cmis separated from G peak Gh appearing in the vicinity of 1520 cmby the Gauss function.

Provided is a magnetic recording medium which maintains high S/N ratio and coercive force (Hc) and has high recording density, even with fine magnetic particles, by further improving crystal orientation of a magnetic recording layer. The magnetic recording medium is provided with an orientation control layer (), a nonmagnetic under layer (), and a magnetic recording layer () on a substrate. The orientation control layer () has an fcc structure and a (111) plane parallel to the substrate. The under layer () has an hcp structure and a (0001) plane parallel to the substrate. An atomic distance of the (111) plane of the orientation control layer () is &#x2212;0.2 &#x212b; to +0.15 &#x212b; to a lattice spacing of the under layer ().

Magnetic recording medium

A protection layer containing carbon as a major component is deposited by plasma CVD. The protection layer has film quality such that, when a spectrum is obtained by excluding photoluminescence from a Raman spectrum in a wavenumber band from 900 cmto 1800 cmobtained by exciting the protection layer with an argon ion laser beam having a wavelength of 514.5 nm and the spectrum is subjected to waveform separation by the Gaussian function to split a D peak appearing around 1350 cmand a G peak appearing around 1520 cm, the ratio Dw/Gw between a half width Dw of the D peak and a half width Gw of the G peak exceeds 0 and is not greater than 2.7.

Magnetic disk, method of manufacturing the magnetic disk and method of evaluating the magnetic disk

The present invention provides a perpendicular magnetic recording medium that can reduce noise by further size reduction and isolation of magnetic grains in a magnetic recording layer and can increase the recording density by improvement of the SNR. A typical configuration of a perpendicular magnetic recording medium according to the present invention is a perpendicular magnetic recording medium having a magnetic recording layer with a granular structure in which non-magnetic grain boundary portions are formed between magnetic grains that have grown continuously in a columnar shape, wherein the grain boundary portions contain a plurality of kinds of oxides.

Perpendicular magnetic recording medium

In a magnetic recording medium which includes a base body ( - ), first and second magnetic layers ( and ), each being of a ferromagnetic material, and a spacer layer ( ) formed between the first and the second magnetic layers for inducing antiferromagnetic exchange interaction between the first and the second magnetic layers, the second magnetic layer located farther from the base body than the first magnetic layer includes a primary layer ( ) and a secondary layer ( ) located nearer to the base body than the primary layer. The primary layer has a primary anisotropic magnetic field while the secondary layer has a secondary anisotropic magnetic field which is smaller than the primary anisotropic magnetic field. The first magnetic layer is for controlling the antiferromagnetic exchange interaction.

Antiferromagnetically coupled magnetic recording medium with dual-layered upper magnetic layer

A magnetic recording medium that is high coersive force, hard to receive influence of thermal fluctuation, and brings about a considerable improvement of S/N ratio, and in which at least an underlayer and a magnetic layer are sequentially laminated on a substrate, wherein a pre-coat layer is interposed between said underlayer and said substrate and said pre-coat layer is constructed by sequentially laminating a lower layer containing Ni and P and an upper layer made of a Cr alloy.

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Singapore, Singapore

Kenji Ayama