Explorations of new phases in the Ga-III/In-III-Mo-VI-Se-IV/Te-IV-O systems

摘要

Systematic explorations of new phases in the Ga-III/In-III-Mo-VI-Se-IV/Te-IV-O systems by hydrothermal syntheses or solid-state reactions at high-temperature led to four new quaternary compounds, namely, Ga(2)MoQ(2)O(10) (Q = Se, Te), In2Mo2Se2O13(H2O) and In2MoTe2O10. Ga(2)MoQ(2)O(10) (Q = Se, Te) are isostructural and their structures feature a 3D network of gallium selenite/tellurite with 12-member ring tunnels along b-axis, the distorted MoO6 octahedra are attached on the wall of the above tunnels. The structure of In2Mo2Se2O13(H2O) features a new pillared-layered architecture composed of 2D indium(III) selenite layers that are interconnected by Mo2O10 dimers, forming 8-membered ring tunnels along the b-axis. The structure of In2MoTe2O10 features a 2D indium oxide layer formed by corner- and edge-sharing InO6 and InO7 polyhedra with MoO4 tetrahedra and TeOn (n = 4, 5) polyhedra hanging on both sides of the layer, there are weak interlayer Te-O bonds of 2.512 angstrom. Results of optical diffuse reflectance spectrum measurements indicate that all four compounds are insulators, which are in agreement with results of band structure calculations based on DFT methods.