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:
May. 26, 2015
Filed:
Jun. 08, 2011
Ernesto E. Marinero, Saratoga, CA (US);
Dieter K. Weller, San Jose, CA (US);
Brian R. York, San Jose, CA (US);
Ernesto E. Marinero, Saratoga, CA (US);
Dieter K. Weller, San Jose, CA (US);
Brian R. York, San Jose, CA (US);
HGST Netherlands B.V., Amsterdam, NL;
Abstract
A perpendicular magnetic recording disk has a graded-anisotropy recording layer (RL) formed of at least two ferromagnetically exchange coupled CoPtCr-oxide magnetic layers (MAG1 and MAG2) with two nucleation films (NF1 and NF2) between the magnetic layers. NF1 is a metal film, preferably Ru or a Ru-based alloy like RuCr, sputter deposited on MAG1 at low pressure to a thickness between about 0.1-1.5 nm. NF2 is a metal oxide film, preferably an oxide of Ta, sputter deposited on NF1 at high pressure to a thickness between about 0.2-1.0 nm. MAG2 is sputter deposited over NF2. NF1 and NF2 provide a significant reduction in average grain size in the RL from a graded-anisotropy RL without nucleation films between MAG1 and MAG2, while also assuring that MAG1 and MAG2 are strongly exchange coupled.