Hydrothermal synthesis and characterization of a new aluminium vanadium oxide hydroxide Al2(OH)3(VO4)

Abstract

A new aluminium vanadium oxide hydroxide analog of the mineral augelite has been prepared by hydrothermal treatment of a 1:1:2.65 aqueous solution of V₂O₅ , Al(NO₃)₃ ·9H₂O, and TMAOH at 200 °C for 5 days. X-Ray powder diffraction data show that this phase crystallizes with monoclinic symmetry with space group C2/m. The structure was solved by using direct methods and then full profile Rietveld refinement was carried out; it's cell parameters are: a=13.5634(2) Å, b=8.2267(2) Å, c=5.31232(9) Å and beta;=112.741(1)° in space group C2/m. The structure contains clusters of edge sharing AlO₆ octahedra and AlO₅ trigonal bipyramids. These clusters are joined together by VO₄ tetrahedra.