Magnetic and electrical properties of BaVS3 and BaVxTi1−xS3

BaVS₃ has an hexagonal structure (space group P6₃/mmc), with chains of V⁴⁺ running along the C direction and largely separated from each other. Small single crystals of BaVS₃ prepared by flux method in BaCl₂ show evidence of 1D antiferromagnetic ordering below 70 K as previously observed on powder samples. The sulphur deficient compound gives ferromagnetic ordering below 16 K with an easy axis of magnetization along the C direction. BaV_xTi_(1?x)S₃ powder samples with 0 <x <1 of the same crystal symmetry as BaVS₃ have also been prepared and the effects of changing the population of d electrons along the V-Ti chains, from 0 electron per site, (BaTiS₃) to 1 electron per site, (BaVS₃) have been studied by X-ray, magnetic and resistivity measurements. A band model is suggested to explain these data.