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:
Nov. 14, 1989
Filed:
Aug. 10, 1987
John C Scott, Saratoga, CA (US);
Eric K Li, Palo Alto, CA (US);
Hudson A Washburn, Santa Clara, CA (US);
Nal T Viswanathan, San Jose, CA (US);
Akshic Memories Corporation, Santa Clara, CA (US);
Abstract
A new high quality, low cost, thin-film magnetic recording member is provided, which has a coercive field strength greater than 650 Oe, a saturation magnetization greater than 10,000 Gauss, and a squareness ratio of 0.9 or larger. The member includes a substrate on which is directly sputter deposited a chromium layer, without the use of an intervening nickel-containing layer between the substrate and the chromium. A nickel-cobalt recording layer is then sputter deposited directly onto the chromium layer. In the preferred mode, the start of that nickel-cobalt deposition begins less than 100 seconds after the chromium deposition is terminated and is followed by the sputtering of a protective layer. Before the chromium deposition, the substrate is preheatead to drive off adsorbed gases, and to establish the proper conditions for the chromium deposition. The substrate is also heated during the time between when the chromium deposition ends and the nickel-cobalt deposition begins.