METHOD OF FORMING INSULATING LAYERS ON OXIDE HIGH-TEMPERATURE SUPERCONDUCTOR BY IRRADIATION WITH GAMMA-RAY

摘要

PURPOSE: To obtain a tunnel junction type Josephson device by forming an insulating layer on the oxide high-temperature superconductor by irradiation with gamma-rays. ;CONSTITUTION: There is no limitation in chemical composition, production process, morphology and shape of the oxide high-temperature superconductor. The high-temperature superconductor is irradiated with gamma-rays to form insulating layers in the areas which differ from the matrix of the superconductor in atomic configuration and have facial extensions such as conjunction interface, crystal grain interface, twinning plane, stacking fault, modulated structural boundary. Or a thin insulating layer is formed where tunnel currency caused by Josephson effect flows through interface inside the superconductor. Further, in order to form an insulating layer of a target thickness selectively only on the surface or inner interface of the superconductor, the exposure rate of gammarays is controlled within the range of from about 0.1 to 2 MR/h and the exposure dose within the range from about 1 to 30 MR.;COPYRIGHT: (C)1993,JPO&Japio