The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 04, 1996
Filed:
Dec. 27, 1994
Mary F Doerner, Santa Cruz, CA (US);
Brent D Hermsmeier, San Jose, CA (US);
Tadashi Yogi, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
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.