Structural and optical studies of KErP2O7 diphosphate

KErP2O7 diphosphate has been synthesized by solid state reaction. It is characterized by X-ray diffraction, Raman and infrared spectroscopies. This compound crystallizes in the monoclinic system with space group P21/c and cell parameters: a = 7.568(2) Å, b = 10.899(2) Å, c = 8.579(2) Å, β = 106.796° (2), Z = 4. The structure of KErP2O7 consists of a three-dimensional framework of ErO6 octahedra, linked by P2O7 diphosphate units, forming tunnels running parallel to [001] which are occupied by K+ atoms. For the first time absorption, excitation and emission spectra of KErP2O7have been investigated; they show characteristic energy levels of the Er3+ ion. The decay time curve for 4F7/2 level of Er3+ ion has also been studied.