SYNTHESIS, STRUCTURE, AND MAGNETISM OF BA2VO(PO4)2.H2O, A NEW BARIUM VANADIUM(IV) PHOSPHATE HYDRATE

The hydrothermal synthesis, which requires the presence of zinc nitrate and tetraethylammonium hydroxide, and the single-crystal structure of Ba2VO(PO4)2.H2O are described. The Ba2VO(PO4)2.H2O structure is built up from discrete, infinite VO(PO4)2.H2O chains, built up from VO6 and PO4 moieties, sparated by 11-coordinate Ba2+ cations. Magnetic susceptibility data for Ba2VO(PO4)2.H2O are consistent with V(IV) and show magnetic ordering below approximately 10 K and paramagnetic behavior from approximately 15-300 K. Crystal data: Ba2VO(PO4)2.H2O, M(r) = 549.56, monoclinic, space group C2/m (No. 12), a = 12.420(3) angstrom, b = 5.219(2) angstrom, c = 6.941(2) angstrom, beta = 104.52(2)-degrees, V = 435.55 angstrom-3, Z = 2, R = 2.14%, R(W) = 2.45% (879 reflections with I > 3 sigma(I)). (C) 1994 Academic Press, Inc.