OXIDE HIGH-TEMPERATURE SUPERCONDUCTOR AND ITS PRODUCTION METHOD

摘要

An oxide high-temperature superconductor in which an oxide high-temperature superconductive thin film high in crystal perfection and excellent in crystal orientation is formed on a crystal substrate of low dielectric constant and its production method are disclosed. When an oxide high-temperature superconductor in which an oxide high-temperature superconductive thin film containing Ba as a constituent element is formed on a sapphire R-face 1, -1, 0, 2 substrate is produced, a first buffer layer made of CeO3 for relaxing the lattice mismatching between the sapphire R-face 1, -1, 0, 2 substrate and the oxide high-temperature superconductive thin film is formed on the the sapphire R-face 1, -1, 0, 2 substrate, a second buffer layer in which Ba of the oxide high-temperature superconductor is replaced with Sr is formed on the first buffer layer, and an oxide high-temperature superconductive thin film is epitaxially grown on the second buffer layer. Even if the material of the firt buffer layer for relaxing the lattice mismatching of the oxide high-temperature superconductive thin film tends to cause an interface reaction with Ba in the oxide high-temperature superconductive thin film, the second buffer layer prevents the interface reaction, thereby epitaxially growing an oxide high-temperature superconductive thin film excellent in crystal perfection and crystal orientation.