HIRATA Toyoaki Osaka Vacuum, Ltd., Senior Engineer, 堺工場開発課, 主任技師(研究職)
TAN Kenji Res.Inst.Elec.Comm., Tohoku University Research associate, 電気通信研究所, 助手 (80282010)
SHIMIZU Yukiya Res.Inst.Elec.Comm., Tohoku University Research associate, 電気通信研究所, 助手 (90282011)
MURAOKA Hiroaki Res.Inst.Elec.Comm., Tohoku University Associate Prof., 電気通信研究所, 助教授 (20239479)
高野 研一 東北大学, 電気通信研究所, 助手 (70250842)
田河 育也 東北大学, 電気通信研究所, 助手 (80212017)
|Budget Amount *help
¥35,700,000 (Direct Cost : ¥35,700,000)
Fiscal Year 1996 : ¥3,600,000 (Direct Cost : ¥3,600,000)
Fiscal Year 1995 : ¥32,100,000 (Direct Cost : ¥32,100,000)
The research team is now investigating a new paradigm of magnetic recording, or "Spinic Storage, " for establishment of a new field of engineering, in which each recorded bit is stored in several single-domain crystallites in order to attain ultra-high density magnetic recording. The aim of this project is to initiate research on fabrication technology of recording media for this new strage scheme. It has been focused to provide a design guideline for the media. In particular, to optimize as a medium for high density recording, its micro magnetic structure of the recording layr is aimed to be clarified from physics of sputtering deposition.
In early 1996, high vacuum sputtering apparatus having an aluminum chamber specialized for such high vacuum was built up, and background pressure of 10^<-8> Torr was confirmed. The apparatus was used for preparing high density magnetic recording disks for read/write experiments. The apparatus has been eventually attained much higher vacuum of 10^<-9>
Torr in late 1996. Evaluation of read/write performance as a high density medium has been performed after optimization of sputtering conditions. The results described below have been obtained : (a) fine grain structure, which is indispensable for low noise magnetic recording media, appeared in recording layr of Co-Cr perpendicular anisotropy film, (b) higher vacuum brought better perpendicular anisotropy, and (c) compositional separation of the Co-Cr film was observed, therefore, (d) magnetic separation among the grains which acts to reduce medium noise was enhanced, however, (e) grain size became rather large, which affects the effect of increase the noise, and (f) in noise measurement its medium noise was smaller than samples by normal vacuum sputtering as a result.
As described, the original requirements for the sputtering apparatus at the start of this project has been almost satisfied, and several knowledge for the high performance perpendicular media was obtained. The media prepared by the sputtering apparatus showed superior read/write characteristics, in particular its high SN ratio, after finishing its optimization of sputtering conditions. These results will be a first step of the ideal Spinic Storage Media, and it will be a basement for realization of ultra-high density recording. Less