Structural, magnetic, and electronic properties of V_xCr _2-x,S₃ (0 < x < 2)

A new family of vanadium-substituted chromium sulfides (V _xCr_2-xS₃, 0 < x < 2) has been prepared and characterized by powder X-ray and neutron diffraction, SQUID magnetometry, electrical resistivity, and Seebeck coefficient measurements. Vanadium substitution leads to a single-phase region with a rhombohedral Cr ₂S₃ structure over the composition range 0.0 < x = 0.75, while at higher vanadium contents (1.6 < x = 2.0) a second single-phase region, in which materials adopt a cation-deficient Cr ₃S₄ structure, is observed. Materials with the Cr ₂S₃ structure all exhibit semiconducting behavior. However, both transport and magnetic properties indicate an increasing degree of electron derealization with increasing vanadium content in this compositional region. Materials that adopt a Cr₃S₄-type structure exhibit metallic behavior. Magnetic susceptibility data reveal that all materials undergo a magnetic ordering transition at temperatures in the range 90-118 K. Low-temperature magnetization data suggest that this involves a transition to a ferrimagnetic state. © 2008 American Chemical Society.