Stoyanov E, Leinenweber K, Groy TL, Malik AS. Ge
0.57Ti
0.43O
2: a new high-pressure material with rutile-type crystal structure.
Acta Crystallogr E Crystallogr Commun 2018;
74:1010-1012. [PMID:
30002905 PMCID:
PMC6038645 DOI:
10.1107/s2056989018008988]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 06/19/2018] [Indexed: 12/03/2022]
Abstract
Single crystals of a GeO2-TiO2 solid solution with the corresponding composition Ge0.57Ti0.43O2 (germanium titanium tetra-oxide) were obtained by devitrification of germania-titania glass at high pressure and temperature. The new compound crystallizes in the rutile structure type (space group P42/mnm), where Ge and Ti share the same position M (site symmetry m.mm), with occupancy values of 0.57 (3) and 0.43 (3), respectively, and one O-atom position (m.2m). The M site is in a sixfold O-atom coordination and, as in the original TiO2 rutile structure, an elongation of the O-M-O bonds along the c-axis direction of the coordination polyhedron and deviation of the angles from 90° lead to a decrease in the coordination symmetry from octa-hedral to tetra-gonal. The Ge and Ti atoms are fully disordered in the structure, which indicates that the rutile structure is surprisingly pliant given the differing sizes of the two cations.
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