Superconductivity of Layered Perovskite synthesized by soft chemistry

摘要

Reduced niobates, MLi{sub}xCa{sub}2Nb{sub}3O{sub}10 (M = Rb, K and Na) and KNa{sub}xCa{sub}2Nb{sub}3O{sub}10 were synthesized by intercalation reaction with n-butyllithium or sodium azide. Ruddlesden-Popper type structure of sodium intercalation compound, KNaCa{sub}2Nb{sub}3O{sub}10, differ from that of the parent compound and lithium intercalation compound, KLiCa{sub}2Nb{sub}3O{sub}10. The magnetic susceptibility measurements showed that the sodium intercalation compound became superconductor with transition temperatures below 3.5 K. New lithium intercalation compound Na{sub}0.1Li{sub}0.8Ca{sub}2.45Nb{sub}3O{sub}10, for an ion exchange compound, Na{sub}0.1Ca{sub}2.45Nb{sub}3O{sub}10, with KCa{sub}2Nb{sub}3O{sub}10 type structure show the diamagnetic signals below 5 K.