| 摘要 |
PURPOSE:To enable efficient taking out of light reproduction output by disposing a 1st ternary amorphous magnetic TbFeCo alloy layer where the sub-lattice magnetization of FeCo is dominant at a room temp. and further, disposing the 2nd ternary amorphous magnetic TbFeCo alloy layer where the sub-lattice magnetization of Tb is dominant at a room temp. and utilizing an exchange bonding. CONSTITUTION:This recording medium has a magnetic layer 4 which is formed by laminating the 1st ternary amorphous magnetic alloy layer of TbFeCo having the axis of easy magnetization in the direction perpendicular to the film plane and expressed by Tbx(Fe1-yCoy)1-x and the 2nd ternary amorphous magnetic alloy layer 3 of TbFeCo having the axis of easy magnetization in the direction perpendicular to the film plane and expressed by Tbx(Fe1-yCoy)1-x and in which the 1st and 2nd amorphous magnetic alloy layers 2, 3 are exchange-bonded. The 1st amorphous magnetic alloy layer 2 is of 0.1<=x<=0.2, 0<y<0.5 and the 2nd amorphous magnetic alloy layer 3 is of 0.2<x<=0.35, 0<=y<0.5. The sub-lattice magnetization of FeCo is dominant in the 1st amorphous magnetic alloy layer 2 at the room temp. and the sub-lattice magnetization of Tb is dominant in the 2nd amorphous magnetic alloy layer. The light reproduction output is taken out efficiency by effectively utilizing the resultant max. angle of Kerr rotation. |
