Sony Corporation

Teruo Sai

Tomoe Ozaki

Noboru Sekiguchi

Junichi Tachibana

Takashi Aizawa

Tetsuo Endo

Ryoichi Hiratsuka

Koji Suzuki

Yoichi Kanemaki

Kazuya Hashimoto

Hikaru Terui

Sogo Oikawa

Hiroto Atagi

A magnetic recording medium includes a flexible and elongated substrate, a soft magnetic layer having an average thickness of 10 nm or more to 50 nm or less, and a recording layer. The soft magnetic layer is disposed between the substrate and the recording layer, and a difference in Young's modulus between the magnetic recording medium and the substrate in a longitudinal direction of the substrate is 2.4 GPa or more.

Magnetic recording medium

A tape-like magnetic recording medium includes a reinforced substrate, and a recording layer arranged on the reinforced substrate, and the reinforced substrate includes a substrate that has a first face and a second face opposed to each other, and has an average thickness of 4 &#x3bc;m or smaller, and a metal layer that contains cobalt, arranged on the first face, the reinforced substrate by itself causing thereon a depth of indentation of 0.25 &#x3bc;m or shallower, when a 0.7-mm-diameter hard sphere is impressed against the second face under 5.0 gf load for 10 seconds.

Magnetic recording medium having reinforced substrate

To provide a magnetic recording tape and the like that have excellent magnetic properties and exhibit a favorable SNR. There are provided a magnetic recording tape and the like including at least: a base layer that includes a long film having flexibility; and a magnetic layer formed on a side of one main surface of the base layer, in which an under layer and a seed layer are provided in the stated order from a side of the magnetic layer toward a side of the base layer between the magnetic layer and the base layer, the underlayer contains at least Co and Cr, and has an average atomic number ratio represented by the following formula (1): CoCr(where y is within a range of 37&#x2264;y&#x2264;45.), and the seed layer formed directly on the base layer has a film thickness of 5 nm or more and 30 nm or less, and contains Ti and O and has an average atomic number ratio represented by the following formula (2): TiO(where x&#x2264;10.) or contains Ti&#x2014;Cr&#x2014;O and has an average atomic number ratio represented by the following formula (3): (TiCr)O(where x&#x2264;10.).

Magnetic recording tape and magnetic recording tape cartridge

A magnetic recording medium has a recording surface having an average surface roughness SRa of 3.0 nm or less, the number of projections having a height of 7.5 nm or more included in a unit region (where the unit region is a square region with each side having a length of 30 &#x3bc;m) of the recording surface is 256 or more, and the number of projections having a height of 15 nm or more included in the unit region of the recording surface is 0 or more and 104 or less.

Magnetic recording medium with controlled surface characteristics

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Miyagi, Japan

Teruo Sai