In1.08Gd0.92Ge2O7: a new member of the thortveitite family

• Published in: Acta crystallographica. Section C, Crystal structure communications Crystal structure communications, 2002-10, Vol.58 (10), p.i135-i137
• Main Authors: Juarez-Arellano, Erick-Adrian, Rosales, Ivonne, Bucio, Lauro, Orozco, Eligio
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Inorganic compounds; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Water, oxides, hydroxides, peroxides
• ISSN: 0108-2701; 1600-5759
• DOI: 10.1107/S0108270102013343

Indium gadolinium digermanium heptaoxide, In1.08Gd0.92Ge2­O7, with a thortveitite‐type structure, has been prepared as a polycrystalline powder material by a high‐temperature solid‐state reaction. As in the mineral thortveitite, the crystal structure belongs to the monoclinic system, with space group C2/m (No. 12). The precise structural parameters were obtained by applying the Rietveld method of refinement to the X‐ray powder diffraction data. This layered structure presents, on one side, a honeycomb‐like arrangement of the unique octahedral site, which is occupied randomly by In and Gd atoms, and, on the other side, sheets of isolated Ge2O7 diortho‐groups made up of double tetrahedra sharing a common vertex and displaying C2h point symmetry. This compound showed a remarkable photoluminescence effect when it was irradiated with the X‐ray beam during the X‐ray diffraction measurements, and with the α beam during the Rutherford back‐scattering spectrometry experiments employed to analyze the chemical stoichiometry.