Structural and magnetic properties of “one-dimensional” barium vanadium triselenide☆☆☆

Abstract BaVSe 3 has been synthesized and its crystal structure determined at 293(2)°K. The structure was solved in the hexagonal space group P6 3 mmc (D 4 6h ) , with a = 6.9990(11) and c = 5.8621(13) A. Scans (2 Θ) of a polycrystalline sample revealed that BaVSe 3 undergoes a transition to an orthorhombic unit cell ( b′ ⋍ 3 1 2 a, a′ ⋍ a, c′ ⋍ c ) at 303(5)°K. Magnetic susceptibility measurements between 4 and 300°K indicate that BaVSe 3 is paramagnetic down to 41(1)°K, where magnetic ordering occurs, with a magnetic moment in the ordered phase of 0.2 μ B per vanadium atom. The orthorhombic lattice distortion may be caused by the “freezing in” of “soft” vibrational modes.