Sodium and Potassium Intercalation into Ta2pds6

Two new phases derived from the layered ternary chalcogenide Ta2PdS6 have been successfully synthesised via the intercalation of sodium or potassium. MTa2PdS6 (M = Na, K) crystallise in monoclinic space group I2/m (No. 12), Z = 2, with lattice parameters a = 8.1366(7) angstrom, b = 3.2876(1) angstrom, c = 15.3279(3) angstrom, beta = 97.407(2)degrees for NaTa2PdS6, and a = 8.3845(3) angstrom, b = 3.2955(1) angstrom, c = 16.7416(8) angstrom, beta = 86.339(3)degrees in the case of KTa2PdS6. The general structure of the parent phase is retained upon intercalation, with increased unit cell volumes of 17.3% and 33.2% for the Na and K intercalates respectively. SQUID magnetometry shows that both intercalates are net diamagnets, but shows a significant reduction of magnetic susceptibility from Ta2PdS6 due to the increase in a Pauli paramagnetic component due to partial band filling.