| 摘要 |
PURPOSE:To form a magnetic field generated state even when after an external magnetic field has been removed by a method wherein a superconductor, containing an alloy superconductor and an oxide high temperature conductor, is cooled down by a critical temperature or lower, and the external magnetic field higher than the lower critical magnetic field is applied thereon. CONSTITUTION:A second kind superconductor is formed at low cost using a superconductor containing an alloy superconductor and an oxide high-temperature superconductor, which can be brought to a critical temperature or lower by liquid nitrogen. Also, the crystal grains of the superconductor is formed in the size sufficiently larger than the intrusion length of magnetic field, and a hole is perforated almost in the center part of each crystal grain. The second kind superconductor is cooled down to the critical temperature or lower, external magnetic field which exceeds the lower part critical magnetic field is applied. The change in magnetization against the above- mentioned application magnetic field shows hysteresis; magnetic flux intrudes into the superconductor in a quantized form, and it has residual magnetization for the inhomogeneity and the crystal grain boundary of the superconductor. As a result, a magnetic field can be left even after the external magnetic field has been removed. |
