| 摘要 |
PURPOSE:To obtain a medium which has a large recording capacity and high stability and safety by covering the front face or both the front and rear faces of a ferromagnetic material with superconductor layers. CONSTITUTION:A prescribed superconducting material such as Ba2Y1Cu3O7-x (O<=x<1) is used as the superconductor and the superconductor layer 1 is formed by sputtering on the front face of the ferromagnetic material layer 2 consisting of CrO2. The very small part of the layer 1 is modified by long-wavelength laser light and is converted to a normal conductor so that the part exhibiting superconductivity and the part exhibiting the normal conductivity are respectively corresponded to digital signals at the time of writing. The medium is cooled down to the temp. at which the superconductivity appears at the time of reading out. Then, the superconductor induces a diamagnetic phenomenon so that the magnetic flux does not pass the part exhibiting the superconductivity and transmits only the part exhibiting the normal conductivity and, therefore, the magnetic flux is detected on the front face of the layer 1 and the information is reproduced. The recording capacity is thereby increased and the stability and safety are improved without being affected by external magnetic fields. |
