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:
Apr. 28, 2009
Filed:
Oct. 13, 2005
Qing Dai, San Jose, CA (US);
Bernd Heinz, San Jose, CA (US);
Yoshihiro Ikeda, San Jose, CA (US);
Mary Frances Minardi, Santa Cruz, CA (US);
Kentaro Takano, San Jose, CA (US);
Qing Dai, San Jose, CA (US);
Bernd Heinz, San Jose, CA (US);
Yoshihiro Ikeda, San Jose, CA (US);
Mary Frances Minardi, Santa Cruz, CA (US);
Kentaro Takano, San Jose, CA (US);
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
A perpendicular magnetic recording disk has a soft magnetic underlayer (SUL) that has high corrosion resistance as well as high moment. The material of the SUL is an alloy comprising Co, Fe, X, and Y; where X is Ta or Nb, Y is Zr or Hf, and the combined amount of X and Y present in the alloy is between about 10 and 20 atomic percent. The atomic ratio of Co to Fe in the alloy is between about 90:10 to 10:90, preferably between about 25:75 and 35:65. The SUL may be a single-layer SUL or a multilayer SUL formed of multiple soft magnetic layers separated by an interlayer film or films.