| 摘要 |
PURPOSE:To increase the reading contrast of mark images by laminating a 1st magnetic layer having a high Curie temp. and low coercive force and a 2nd magnetic layer having the relatively low Curie temp. and high coercive force with respect to the 1st magnetic layer and forming the 1st magnetic layer of a rare earth transition metal alloy. CONSTITUTION:This recording medium is formed by laminating the 1st magnetic layer 23 having the high Curie point and the low coercive force and the 2nd magnetic layer 22 having the relatively low Curie temp. and the high coercive force with respect to the 1st magnetic layer 23. The 1st magnetic layer 23 consists of the rare earth transition metal alloy contg. light rare earth elements. The light rare earths are preferably selected from Ce, Pr, Nd, and Sm. The 2nd magnetic layer 22 is preferably formed of the alloy of rare earths selected from Tb and Dy and transition metals selected form Fe and Co. Exposing with low energy is executed in this way and the sufficient reading contrast of the mark images is obtd. |
