Low-Temperature Synthesis of K-Ba-Bi-O Oxides in KOH Solution

摘要

The reaction of KBiO3-delta with Ba2+ ions at a Ba : Bi ratio of 0.5.1.6 (mol.) in a 10 M. KOH solution under reflux (similar to 140 degrees C) has furnished oxides, which composition and structure have been studied by X-ray diffraction, energy dispersive X-Ray, and chemical analysis. Pseudo cubic (a = 4.271.4.285 A) perovskite-like phases of barium.bismuth(III,V).potassium oxides with insignificant impurity of sodium have been formed in the KBiO3-delta-Ba2+-OH -H2O system during 1 h. The products have been characterized by an average oxidation state of bismuth Bi = 4.36-4.59. Barium content in the resulting oxides has increased with an increase in its concentration in the charge. According to the Ba-Bi ratio, the resulting phases can be classified as non-superconducting oxides of homologous series MxBamBim+nOy (x < n), MxBamBim+nOy, and (M, Ba)(m+n)BimOy (m = 1, 2,...; n = 0, 1, 2, ...), M = K, Na.