HOMOGENEITY RANGE AND SOME PHYSICAL-PROPERTIES OF INTERCALATION COMPOUNDS OF MNXTAS2

The intercalation compounds of MnxTaS2 were synthesized by heating a m ixture of TaS2 and Mn metal in an evacuated silica tube. The single-ph ase region was determined to be 0.20 less than or equal to x less than or equal to 0.50 in MnxTaS2 at 1000 degrees C. The hexagonal c-axis i ncreased simply with increasing manganese content x, while the a-axis had anomalies at x = 1/4 and 1/3 where different superlattices were ob served. The temperature dependence of electrical resistivity showed me tallic behavior. The temperature variation of magnetic susceptibility obeyed a Curie-Weiss law. The Weiss constant (paramagnetic Curie tempe rature) theta decreased with x and the value changed from positive to negative at x = 0.50, suggesting the change of exchange interactions f rom ferromagnetic to antiferromagnetic. The valance state of manganese in MnxTaS2 was evaluated as divalent by P-eff (effective Bohr magneto n) calculated from the Curie constant. (C) 1995 Academic Press, Inc.