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. 01, 2021
Filed:
Mar. 31, 2020
Showa Denko K.k., Tokyo, JP;
Takayuki Fukushima, Chiba, JP;
Chen Xu, Chiba, JP;
Lei Zhang, Chiba, JP;
Hisato Shibata, Chiba, JP;
Takehiro Yamaguchi, Chiba, JP;
Kazuya Niwa, Chiba, JP;
Tomoo Shige, Chiba, JP;
Hiroaki Nemoto, Chiba, JP;
Yuji Umemoto, Chiba, JP;
Hiroshi Koyanagi, Chiba, JP;
SHOWA DENKO K.K., Tokyo, JP;
Abstract
A magnetic recording medium includes a substrate, an underlayer, and a magnetic layer that are arranged in this order. The magnetic layer has a granular structure including magnetic grains having a L1crystal structure, and grain boundary parts having a volume fraction in a range of 25 volume % to 50 volume %. The magnetic grains have a c-axis orientation with respect to the substrate. The grain boundary parts include a material having a lattice constant in a range of 0.30 nm to 0.36 nm, or in a range of 0.60 nm to 0.72 nm.