Syntheses and Characterization of a Family of Vanadate Compounds Ba3M(V2O7)2 (M = Co, Mn, Mg, or Zn) with an Edge-Shared [M2O10] Dimer Structure

A series of vanadate compounds Ba3M(V2O7)2 (M = Co, Mn, Mg, or Zn) are synthesized by a conventional high-temperature solid-state reaction. Four compounds are found to exhibit a similar structure, which all crystallize in the monoclinic system of space group P21/c. V5+ ions are tetrahedrally coordinated, forming corner-shared (V2O7)4– groups, while M2+ ions are octahedrally coordinated, forming edge-shared [M2O10] dimers. Isolated {M2V8O28}∞ clusters composed of [M2O10] dimer and (V2O7)4– groups form a pseudo-one-dimensional chain running along the a-axis. Magnetic measurements confirm that both Ba3Co(V2O7)2 and Ba3Mn(V2O7)2 show antiferromagnetic interaction exchanges in the systems, while luminescence measurements confirm that Ba3Mg(V2O7)2 and Ba3Zn(V2O7)2 have a broad emission band from 400 to 650 nm under 256 nm UV irradiation at room temperature.