Study of chevrel phase compounds InMo 6(Se 1− xS x) 8 under high pressure

Abstract

The pressure dependence of the superconducting transition in the Chevrel compounds InMo 6(Se 1− x S x ) 8, with x = 0.0, 0.18 and 0.30 was determined magnetically up to a hydrostatic pressure of 17 kbar using a clamp technique. The rhombohedral to rhombohedral structural transition was measured resistively for the x = 0.18 compound under quaihydrostatic pressures up to 25 kbar employing an anvil-arrangement. Pressure was found to suppressed to superconducting transition temperature T c while enhancing the structure transition temperature T L of InMo 6(Se 1− x S x ) 8, in general. In fact, the negative pressure effect on the T c of InMo 6Se 8 observed is the largest among the non-rare-earth ternary Chevrel selenides. However, the T c of InMo 6(Se 0.82S 0.18) 8 increases with pressures above 10 kbar following the initial decrease. The results and their implications will be discussed.