公开(公告)号：US20180366152A1

公开(公告)日：2018-12-20

申请号：US16008147

申请日：2018-06-14

Applicant: FUJIFILM Corporation

Inventor： Kenji NAOI ,  Masashi SHIRATA

IPC: G11B5/706 ,  C01G49/00 ,  G11B5/714 ,  G11B5/708

Abstract: Provided is hexagonal strontium ferrite powder for magnetic recording, in which an activation volume is 800 to 1,500 nm3, a content of rare earth atom with respect to 100 atom % of iron atom is 0.5 to 5.0 atom %, and a rare earth atom surface portion uneven distribution is provided.

公开(公告)号：US20140255728A1

公开(公告)日：2014-09-11

申请号：US14200329

申请日：2014-03-07

Applicant: FUJIFILM Corporation

Inventor： Masashi SHIRATA

IPC: G11B5/714

CPC classification number: G11B5/714 ,  G11B5/70678

Abstract: An aspect of the present invention relates to a magnetic recording medium, which comprises magnetic layer comprising ferromagnetic powder and binder on a nonmagnetic support, wherein the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, the ferromagnetic hexagonal ferrite powder has an activation volume ranging from 800 nm3 to 1,300 nm3, and 1 percent to 50 percent of particles constituting the ferromagnetic hexagonal ferrite powder are ferromagnetic hexagonal ferrite particles, each of which has an indentation with a depth of equal to or more than 1/10 of an equivalent projected circle diameter of the ferromagnetic hexagonal ferrite particle.

Abstract translation: 本发明的一个方面涉及一种磁记录介质，其包括在非磁性载体上包含铁磁性粉末和粘合剂的磁性层，其中铁磁性粉末是铁磁六方铁氧体粉末，铁磁六方铁氧体粉末的活化体积为800nm 3 至1,300nm 3，构成铁磁性六角铁氧体粉末的粒子的1〜50％为铁磁性六方晶系铁氧体粒子，其各自具有深度等于或大于其的等效投影圆直径的1/10的压痕 铁磁六角铁氧体颗粒。