Solid State Ionics, Vol.172, No.1-4, 469-475, 2004
Structure-property relationships in ordered-defect sulphides
Ordered-defect phases of stoichiometry AB(2)S(4) adopt a structure in which dichalcogenide slabs are separated by defective layers containing cations in 50% of the octahedral sites. The physical properties of such phases may be varied systematically by chemical substitution. This may be effected preferentially at sites in either the dichalcogenide or defective layers or at both sites simultaneously. The resulting cation distribution is related to the electronic properties of the constituent ions. In the series VxCr3-xS4 (0:! X:5 1), there is an abrupt change in this distribution at x greater than or equal to 0.4, which drives the system into a semiconducting state, with a concomitant loss of long-range magnetic order. Substitution within the dichalcogenide slab in NiCr2-xVxS4 (0