SYNTHESIS OF LA(1-X)M(X)TIO(3) (M=NA,K LESS-THAN-OR-EQUAL-TO-X-LESS-THAN-OR-EQUAL-TO-0.4) AND THE ELECTRICAL-PROPERTIES

Polycrystalline materials of La(1-x)M(x)TiO(3) (M = Na, K; 0 less than or equal to x less than or equal to 0.4) were prepared by solid-state reactions under an Ar atmosphere and their electrical properties were investigated as possible candidates for superconducting oxides. XRD a nalysis showed that the formation of orthorhombic perovskite-type comp ounds were obtained when x = 0 (LaTiO3) and that pseudo-cubic or cubic phases were obtained when x greater than or equal to 0.1. The lattice constants of the products decreased when x increased, suggesting the formation of solid solutions. There were small deficiencies of the alk ali metals. The products in both systems showed semiconductor to metal transitions as temperature decreased when x greater than or equal to 0.1, and striking decreases of resistivity around 25 K were observed i n both systems.