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:
Feb. 20, 1996
Filed:
May. 28, 1993
Richard H Ahlert, San Jose, CA (US);
James K Howard, Morgan Hill, CA (US);
Todd L Hylton, San Jose, CA (US);
Michael A Parker, Fremont, CA (US);
Muhammad I Ullah, Morgan Hill, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A high-density recording media comprising longitudinally oriented polycrystalline barium ferrite exhibits large coercivity, corrosion resistance, high hardness and durability. Films are prepared by on-axis sputtering at ambient temperatures from stoichiometric targets followed by a post-deposition anneal at approximately 850.degree.C. to induce crystallization. Crystallization yields a magnetic film with large in-plane remanence and a fine scale texturing that greatly improves the tribological performance of barium ferrite disks. Exceptional durability can be achieved on disks without overcoats. Grain sizes as small as 200 .ANG. are produced by doping with small amounts of Cr.sub.2 O.sub.3 or other additives. Coercivities greater than 4000 Oe are achieved even in small grain films.