公开(公告)号：US20170221513A1

公开(公告)日：2017-08-03

申请号：US15420425

申请日：2017-01-31

申请人： HITACHI MAXELL, LTD.

发明人： Toshio HIROI ,  Shinji KAWAKAMI ,  Kenji TANAKA

IPC分类号： G11B5/65 ,  G11B5/78 ,  G11B5/725

CPC分类号： G11B5/78 ,  G11B5/00813 ,  G11B5/70 ,  G11B5/70642 ,  G11B5/725

摘要： A magnetic recording medium of the present invention includes a non-magnetic substrate, and a magnetic layer containing a magnetic powder. The magnetic powder is constituted by an ε-iron oxide powder. The magnetic layer has a squareness in a thickness direction of 0.65 or more. In a differential curve obtained by differentiating a hysteresis curve in the thickness direction of the magnetic layer, two or more peaks are present. In a case where, out of peaks in the same direction among the above-described peaks, a local maximum of a largest peak in a magnetic field range of +500 oersted [Oe] or more is taken as P1 and a local maximum of a largest peak in a magnetic field range of −500 oersted [Oe] or more and less than +500 oersted [Oe] is taken as P2, a relationship below is satisfied: 0.25≦P2/P1≦0.60.