公开(公告)号：US12087340B2

公开(公告)日：2024-09-10

申请号：US17760555

申请日：2020-09-04

申请人： Sony Group Corporation

发明人： Natsuki Ichise ,  Minoru Yamaga ,  Katsunori Maeshima ,  Masaru Terakawa ,  Takeshi Takahashi ,  Tomoe Sato ,  Takashi Kataguchi

IPC分类号： G11B5/706 ,  G11B5/73

CPC分类号： G11B5/739

摘要： A magnetic recording medium is a tape-shaped magnetic recording medium that has a recording layer including an ε-iron oxide particle. An area ratio Rlow (=(Slow/Stotal)×100) of a total area Stotal of an SFD curve of the recording layer in a perpendicular direction and an area Slow of the SFD curve in which a coercivity Hc is in a range from −500 [Oe]≤Hc≤500 [Oe] is equal to or less than 5.5%.

公开(公告)号：US11551711B2

公开(公告)日：2023-01-10

申请号：US17430874

申请日：2020-02-14

申请人： Sony Group Corporation

发明人： Natsuki Ichise ,  Masaru Terakawa ,  Katsunori Maeshima ,  Takashi Kataguchi ,  Takeshi Takahashi

IPC分类号： G11B5/706 ,  H01F1/34

摘要： A cobalt ferrite magnetic powder includes magnetic particles that have a uniaxial crystal magnetic anisotropy and contain cobalt ferrite. A peak top 2θ of a (3, 1, 1) plane determined by powder X-ray diffractometry using a CoKα ray is 41.3° or more and 41.5° or less. Some Cos contained in the magnetic particles are substituted with at least one selected from the group consisting of Zn, Ge, and a transition metal element other than Fe.