Continuous Fabrication and Perpendicular Recording Characteristics of Co-Cr Magnetic Tape
A new sputtering source (named an SPT target) was modified so as to enable high-rate deposition and continuous fabrication of Co-Cr composite perpendicular recording media. In order to improve the orientation and crystallinity of the Co-Cr layer and the permalloy backlayer, the aperture position was optimized and a magnetic return path plate was added to the target. The Co-Cr tape medium deposited on a 9 m thick polyimide film using this modified sputtering source showed good high-density recording performance.
Effects of high deposition rate on perpendicular magnetic recording media prepared by SPT target.
A new sputtering source (named SPT target) has been proposed, aiming at improvement in a continuous sputtering system for a Co-Cr double layer perpendicular recording medium. Very low discharge voltage was realized compared with sputtering source targets for magnetic medium so far proposed. Both Permalloy and Co-Cr films deposited by the source showed high crystal orientation even at a high-rate deposition. High through-input of Permalloy and Co-Cr layers deposition corresponded to higher 2nd peak ratio and D50* on recording density response for the resulting media. It was shown that the new SPT target is preferable for getting a high through-put in a magnetic recording medium production.
Co-Cr スパッタ膜の連続作製における垂直磁気異方性の改善法
A roll coater system was investigated for establishment of a mass production system for Co-Cr perpendicular recording media. Improvements of the crystal orientation and the magnetic properties of Co-Cr media with the introduction of new seed layers of Co-Cr itself are described. In the light of these results, a Co-Cr film with a composition gradient in the growing direction but without any seed layer has been proposed and its properties discussed. It was found that the anisotropy field Hk can be remarkably increased for the film with a composition gradient over that of a conventional Co-Cr film. It is concluded that the newly developed Co-Cr film is very suitable for mass production by a roll coater because of its simplified process which requires no sputtering of any seed layers.