Showa Denko K.k.

Hideaki Takahoshi

Hiroshi Sakai

Daisuke Amiya

Yuki Yoshida

Hisato Shibata

Akira Kikuchi

Takahiro Ukai

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.

Magnetic recording medium and magnetic storage apparatus

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.

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.

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.

Servo information recording method and magnetic storage apparatus

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.

Perpendicular magnetic recording medium and magentic recording and reproducing apparatus

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.

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Chiba, Japan

Hideaki Takahoshi