Title :
Spinel ferrite Co-/spl gamma/Fe/sub 2/O/sub 3/ perpendicular media on exchange-coupled underlayer
Author :
Koujima, J. ; Nakata, K. ; Ando, T. ; Shimomai, K. ; Doi, T. ; Sugiyama, M. ; Cromwell, E.F.
Author_Institution :
R&D Div., Toda Kogyo Corp., Hiroshima, Japan
Abstract :
In ultra-high density perpendicular magnetic recording, double-layered media consisting of a recording layer on a soft magnetic layer are required. For the recording layer, spinel ferrite Co-γFe/sub 2/O/sub 3/ films have been investigated. The films have advantages of high coercivity, high stability without protective layer, and low noise performance. For the soft magnetic layer, exchange-coupled CoZrNb/CoSm underlayers have been studied. The CoSm hard magnetic layer pins the domains of amorphous CoZrNb soft magnetic layer effectively, and decreases the noise coming from the soft magnetic layer. Also, signal stability under stray fields and high frequency responses have been observed in the media consisting of a CoCrTa recording layer on the CoZrNb/CoSm underlayers. In this study, the preparation and properties of Co-γFe/sub 2/O/sub 3/ media, combined with exchange-coupled CoZrNb/CoSm underlayers, are described.
Keywords :
cobalt; cobalt alloys; coercive force; ferrites; frequency response; magnetic multilayers; magnetic recording noise; niobium alloys; perpendicular magnetic recording; samarium alloys; soft magnetic materials; sputter deposition; stability; zirconium alloys; Co-Fe/sub 2/O/sub 3/; CoFe/sub 2/O/sub 3/-CoZrNb-CoSm; CoSm hard magnetic layers; DC magnetron sputtering; amorphous CoZrNb soft magnetic layer domain pinning; double-layered media; exchange-coupled CoZrNb/CoSm underlayers; exchange-coupled underlayers; film stability/noise performance; frequency response; high coercivity films; magnetic coercivity; recording layers; soft magnetic layers; spinel ferrite Co-Fe/sub 2/O/sub 3/ perpendicular media; stray field signal stability; ultra-high density perpendicular magnetic recording; Amorphous magnetic materials; Coercive force; Ferrite films; Magnetic domains; Magnetic films; Magnetic noise; Perpendicular magnetic recording; Protection; Soft magnetic materials; Stability;
Conference_Titel :
Joint NAPMRC 2003. Digest of Technical Papers [Perpendicular Magnetic Recording Conference]
Conference_Location :
Monterey, CA, USA
Print_ISBN :
0-7803-7746-X
DOI :
10.1109/NAPMRC.2003.1177026
