Optical study in a novel quaternary ionic crystal doped with europium

Abstract

In this Letter, the novel quaternary alkali halide crystal KCl:KBr:RbCl:RbBr doped with europium, each component in a 25% molar fraction and 0.5% of Eu ++, is reported. The value of its refractive index was measured, the crystallographic properties are characterized by X-ray diffractometry, the optical properties were studied by optical absorption in UV-VIS region, and by photoluminescence under N 2 laser excitation at 12 K and at RT. The diffractometer diagram of a powder sample shows a single phase and a well defined value of the lattice constant. From the optical absorption spectra of europium, the value of 10 Dq parameter is obtained, the result is in good agreement with X-rays analysis. It was also observed that decay times of the blue emission is independent of temperature and only one decay component is present in the quenched samples. From obtained data, it is suggested that the symmetry of the Eu ++ site in the quaternary crystal KCl 0.25KBr 0.25RbCl 0.25RbBr 0.25 is similar to a quenched sample of a single component crystal.