Solid-state synthesis, X-ray powder investigation and IR study of alpha-Mg-3[BPO7]

alpha-Mg-3[BPO7] (low temperature form) which is isostructural with Zn-3[BP O7] has been synthesized by the solid-state reactions of MgHPO4.H2O with Mg CO3 and H3BO3 at 1200 degrees C, Mg3B2O6 with MgCO3 and (NH4)(2)HPO4 at 110 0 degrees C, and MgO with B2O3 and P2O5 at 1100 with the molar ratios of 1: 2:1, 1:3:2 and 6:1:1, respectively. The structure of alpha-Mg-3[BPO7] was f ound to be orthorhombic (as already reported), with refined unit cell param eters of a = 8.495(3), b = 4.886(1) and c = 12.565(4) Angstrom, the space g roup is Immm with Z = 4. The indexed Xray powder diffraction data and the I R spectrum of alpha-Mg-3[BPO7] are also given. The latter reveals trigonal planar coordination of boron. (C) 1998 Elsevier Science Limited. All rights reserved.