公开(公告)号：US20230317110A1

公开(公告)日：2023-10-05

申请号：US18191311

申请日：2023-03-28

Applicant: FUJIFILM Corporation

Inventor： Noriko OYANAGI ,  Tatsuya YAMASHITA

IPC: G11B5/708 ,  G11B5/72

CPC classification number: G11B5/708 ,  G11B5/72

Abstract: Ra measured on a surface of a magnetic layer is 2.5 nm or less, and Δ(HD−HB) between a protrusion height HD with a height of a peripheral base region of 0 nm as a reference, which is measured by AFM, for a region specified as a dark region in a first binarization-processed image of a reflected electron image obtained by imaging the surface of the magnetic layer with SEM and a protrusion height HB with a height of a peripheral base region of 0 nm as a reference, which is measured by AFM, for a region specified as a bright region in a second binarization-processed image of the reflected electron image obtained by imaging the surface of the magnetic layer with SEM, the second binarization processing being performed on a higher gradation side than the first binarization processing, is 0.7 nm or more.

公开(公告)号：US20170004856A1

公开(公告)日：2017-01-05

申请号：US15197046

申请日：2016-06-29

Applicant: FUJIFILM Corporation

Inventor： Toshio TADA ,  Akinori SUGISHIMA ,  Tatsuya YAMASHITA ,  Norihito KASADA ,  Masahito OYANAGI

IPC: G11B5/842 ,  G11B5/706

CPC classification number: G11B5/842 ,  G11B5/70678 ,  G11B5/714

Abstract: The magnetic recording medium has a magnetic layer comprising ferromagnetic powder and binder on a nonmagnetic support, wherein the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, and the ferromagnetic hexagonal ferrite powder has a crystallite volume as determined by X-ray diffraction analysis ranges from 1,000 nm3 to 2,400 nm3, and a ratio of the crystallite size Dx(107) obtained from a diffraction peak of a (107) plane to a particle size in a direction of an easy axis of magnetization DTEM as determined by observation with a transmission electron microscope, Dx(107)/DTEM, is greater than or equal to 1.1.

Abstract translation: 磁记录介质具有在非磁性载体上含有铁磁性粉末和粘合剂的磁性层，其中铁磁性粉末为铁磁性六角铁氧体粉末，铁磁性六方晶系铁氧体粉末的X射线衍射分析的微晶体积为1000nm 3 至（2,400nm 3），通过透射电子显微镜观察确定由（107）面的衍射峰获得的微晶尺寸Dx（107）与易磁化轴DTEM方向上的粒径的比例， Dx（107）/ DTEM，大于或等于1.1。