International Business Machines Corporation

Brent D Hermsmeier

Mary Frances Doerner

Tadashi Yogi

A high-density longitudinal recording medium comprising a CoPtCrB alloy with a chromium content in excess of 17 atomic percent exhibits high coercivity, low noise, and high Curie temperatures. Films are prepared by sputter depositing a chromium or chromium alloy underlayer on a non-magnetic substrate. A strong [100] crystallographic orientation of the underlayer is required to achieve a low noise, high coercivity medium. This orientation is achieved by depositing the underlayer on a negatively biased substrate under high temperature, low pressure conditions. The oriented underlayer prevents the subsequently deposited CoPtCrB alloy from orienting itself in its preferred, c axis vertical orientation. The CoPtCrB alloy comprises 4 to 12 percent platinum, 18 to 23 percent chromium and 2 to 10 percent boron.

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San Jose, CA, United States of America

Brent D Hermsmeier