| 摘要 |
PURPOSE:To obtain a Tl-base oxide superconductor having high critical temp., by preparing a starting material with the Tl content decreased and the contents of Ca and Cu increased as compared with Tl2Ba2Can-1CunOy and sintering the starting material. CONSTITUTION:Tl2O3, BaCO3, CaO, CuO, etc., as the raw materials are mixed to prepare a starting material, in which the Tl content is decreased and the contents of Ca and Cu increased as compared with a stoichiometry value of the composition expressed by Tl2Ba2Can-1CunOy ((n) is an integer of >=2, and (y) is a number meeting the requirement of valence). The mixing ratio of the raw materials in number of atoms of Tl, Ba, Ca and Cu is appropriately controlled to (2-u):2:(n-1+v):(n+w) (where 0<u<0.7, 0<v<0.5 and 0<w<0.5). The mixture is sintered to synthesize an oxide superconductor having a crystal structure expressed by Tl2Ba2Can-1CunOy as a single phase. |
