Two new glaserite-type orthovanadates: Rb2KDy(VO4)2 and Cs1.52K1.48Gd(VO4)2

Abstract

The crystal structures of dirubidium potassium dysprosium bis(vanadate), Rb2KDy(VO4)2, and caesium potassium gadolinium bis(vanadate), Cs1.52K1.48Gd(VO4)2, were solved from single-crystal X-ray diffraction data. Both compounds, synthesized by the reactive flux method, crystallize in the space group P\overline{3}m1 with the glaserite structure type. VO4 tetrahedra are linked to DyO6 or GdO6 octahedra by common vertices to form sheets stacking along the c axis. The large twelve-coordinate Cs+ or Rb+ cations are sandwiched between these layers in tunnels along the a and b axes, while the K+ cations, surrounded by ten oxygen atoms, are localized in cavities.