No abstract

Luminescence phenomenon from high-Tc oxide superconductors (HTSC's) is peculiar to this materials, not to metal-superconductors.Because of the sensitivity to crystalline defects (stoichiometory, impurities, an oxygen vacancies), luminescence measurement is expected to be effective for characterization method for HTSC's. In this study, cathodeluminescence (CL) is proposed, the relations of superconductivity with CL have been investigated as a function of the amount of impurities (raw materials, intermediate products) and oxygen contents in Y-Ba-Cu-O (YBCO) system HTSC's. Characteristic CL have been successfully observed in the YBCO samples controlled the amount of impurites. As the amount of impurities increased, the luminous areas increased and critical temperature Tc fell down. Electron probe micro analizer clarified that CL in visible region was attributed to the impurity phases in YBCO samples. Moreover, the luminescence spectra in the luminous areas were idetified with the spectra which were obtained from the impurities itself. From thses results, cathodeluminescence is the very useful method to obtain the informations about the impurities in HTSC's.