PREPARATION AND PHYSICAL-PROPERTIES OF FEXTAS2 (0.15-LESS-THAN-OR-EQUAL-TO-X-LESS-THAN-OR-EQUAL-TO-0.50) COMPOUNDS

The intercalation compounds of the Fe-Ta-S system were synthesized by beating the mixture of 1T-TaS2 and metal Fe in a sealed evacuated silica tube, The single phase region was 0.15 ≤ x ≥ 0.50 in FexTaS2. The hexagonal a-axis was almost constant, while the c-axis increased simply with increasing iron content x . Temperature dependence of electrical resistivity showed metallic behavior. Mössbauer effect measurements showed that the iron was high-spin state Fc2+ in FexTaS2. The temperature variation of magnetic susceptibility obeyed a Curie-Weiss law, The Weiss temperature θ decreased with x and changed the value from positive to negative at x ≃ 0.4 suggesting the change of exchange interactions from ferromagnetic to antiferromagnetic. © 1994 Academic Press, Inc.