CaYGaO4; a fully ordered novel olivine type gallate

CaYGaO4 was synthesized by conventional solid-state method. Its crystal structure was determined by single-crystal X-ray diffraction technique to be olivine structure type. CaYGaO4 comprises an orthorhombic space group Prima, with lattice constants of a = 11.3484(1) angstrom, b = 6.5712(6) angstrom and c = 5.2818(8) angstrom. All three cations occupy their specific atomic positions and the structure is fully ordered. The crystallographic ordering scheme in the new gallate system, is different from those reported for the previously studied silicate and germanate olivines. The partial replacement of the Ga3+ by Fe3+ ions could be achieved, resulting in a series of solid solutions with the chemical composition of CaYGa1-xFexO4 (0 < x <= 0.50). The unit cell volumes of the doped variants are consistent with Vegard's law. (C) 2014 Elsevier B.V. All rights reserved.