Abstract: | BaVSe3 has been synthesized and its crystal structure determined at 293(2)°K. The structure was solved in the hexagonal space group P63/mmc (D46h), with a = 6.9990(11) and c = 5.8621(13) Å. Scans (2 Θ) of a polycrystalline sample revealed that BaVSe3 undergoes a transition to an orthorhombic unit cell (b′ 31/2 a, a′ a, c′ c) at 303(5)°K. Magnetic susceptibility measurements between 4 and 300°K indicate that BaVSe3 is paramagnetic down to 41(1)°K, where magnetic ordering occurs, with a magnetic moment in the ordered phase of 0.2 μB per vanadium atom. The orthorhombic lattice distortion may be caused by the “freezing in” of “soft” vibrational modes. |