Patent ID: 10614849

Abstract:
A heat-assisted magnetic recording medium includes a substrate, an underlayer, and a magnetic layer including an alloy having a L10 crystal structure and first and second layers, arranged in this order. Each of the first and second layers has a granular structure including C, SiO2, 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 SiO2 with respect to BN in each of the first and second layers is 0.25 to 3.5. Vol % of SiO2 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.