Ba-Y-Cu-O超伝導酸化物と基板材料の反応性

抄録

The reactivity of Ba₂YCu₃O₇ to metal oxides and carbonates was studied to develop a substrate material for superconducting oxide films, The superconducting oxide of Ba₂YCu₃O₇ reacted with most of the conventional substrate materials to form oxide compounds. BaZrO₃, SrCO₃, and CaSiO₃ were less reactive to Ba₂YCu₃O₇, and the onset critical temperature of Ba₂YCu₃O₇ remained unaltered after heating with these materials at 1223K. Zero resistivity temperature (T_c (end)), however, decreased depending on these materials. Coexistence of the substrate materials during heating increased the amount of oxygen vacancies in Ba₂YCu₃O₇, resulting in an increased lattice constant of c axis of Ba₂YCu₃O₇, The substrate materials for preparing high T_c superconducting oxide films require no interaction with the amount of oxygen vacancy of Ba₂YCu₃O₇ in addition to the low chemical reactivity to Ba₂YCu₃O₇, CaSiO₃ and BaZrO₃ were excellent substrate materials.