Crystal structure of K3EuSi2O7 Scientific paper

Abstract

As part of research on the flux technique for growing alkali rare-earth elements (REE) containing silicates, tripotassium europium disilicate, K3EuSi2O7, was synthesized and characterized by single-crystal X-ray diffraction. It crys­tal­lizes in the space group P63/mcm. In the crystal structure of the title com­pound, one part of the Eu cations are in a slightly distorted octahedral coor­dination and the other part are in an ideal trigonal prismatic coordination envi­ronment. The disilicate Si2O7 groups connect four EuO6 octahedra and one EuO6 trigonal prism. Three differently coordinated potassium cations are loc­ated between them. Silicates containing the larger rare earth elements usually crystallize in a structure that contains the rare-earth cation in both a slightly distorted octahedral and an ideal trigonal prismatic coordination environment.