| 摘要 |
PURPOSE:To obtain a vertical magnetic recording medium having an excellent electromagnetic conversion property and with a high efficiency of production, by decreasing the Cr/Co ratio toward the surface of a magnetic layer in a magnetic recording substance that is obtained by forming a magnetic layer composed mainly of Co and Cr on a nonmagnetic substrate. CONSTITUTION:For a vertical magnetic recording medium obtained by forming the Co-Cr sputtered film (magnetic layer) 12 on the nonmagnetic substrate 2, the larger the amount of Cr of the film 12 the higher the film forming speed. But the electromagnetic conversion property is lowered since the magnetization by saturation is reduced. Both the orientation and crystallizability of a thin film are regulated by the substrate. In this connection, the Cr content is increased at the area near the interface 14 between the magnetic layer 12 and the substrate 2 to form a layer having a good vertical orientation property of magnetism. Then the layer 12 is formed by decreasing the Cr content successively. In such way, the magnetic layer 12 having a small Cr content as a whole (accordingly a good electromagnetic conversion property) can be formed with a fast film forming speed. |
