Showa Denko Assigned Patent

Showa Denko K.K., Tokyo, Japan, has been assigned a patent (10,614,849) developed by Fukushima, Takayuki, Take, Koji, Shibata, Hisato, Yamaguchi, Takehiro, Shige, Tomoo, Zhang, Lei,Xu, Chen, Umemoto, Yuji, Koyanagi, Hiroshi, Niwa, Kazuya, and Kanbe, Tetsuya, Chiba, Japan, for a “heat-assisted magnetic recording medium and magnetic storage apparatus.“

The abstract of the patent published by the U.S. Patent and Trademark Office states: ”A heat-assisted magnetic recording medium includes a substrate, an underlayer, and a magnetic layer including an alloy having a L1.sub.0 crystal structure and first and second layers, arranged in this order. Each of the first and second layers has a granular structure including C, SiO.sub.2, and BN at grain boundaries. Vol % of the grain boundaries in each of the first and second layers is 25 to 45 vol %. Vol % of C in the first layer is 5 to 22 vol %, and a volume ratio of SiO.sub.2 with respect to BN in each of the first and second layers is 0.25 to 3.5. Vol % of SiO.sub.2 in the second layer is greater than that of the first layer by 5 vol % or more. Vol % of BN in the second layer is smaller than that in the first layer by 2 vol % or more.”

The patent application was filed on July 23, 2019 (16/519,157).