| 摘要 |
PURPOSE:To expand the range of selecting magnetic materials by forming a magneto-optical recording medium of a superconducting material and magnetic material and changing the temp. of the superconducting material by laser light, thereby controlling the influence of the external magnetic field on the magnetic material. CONSTITUTION:The laser light 1 is focused through a lens 2 and a transparent substrate 3 onto a magnetic material layer 4 and a superconducting material layer 5. The magnetic field of a coil 6 is shut off by the layer 5 and the layer 4 is not affected by the magnetic field when the laser light 1 is not irradiated. The recording of the layer 4 is, therefore, preserved. The temp. of the focused part rises when the laser light 1 is projected thereon. The magnetic field of the coil 6 determines the direction of the layer 4 when the temp. exceeds the critical temp. of the layer 5. Recording and erasing can be executed by inverting the direction of the magnetic field. The layer 4 is irradiated by the laser output lower than the critical temp. of the layer 5 and the angle of Kerr rotation thereof is detected at the time of reading out. The broad selection of the magnetic materials is thereby enabled. |
