Optical study in a novel quaternary ionic crystal doped with europium

In this Letter, the novel quaternary alkali halide crystal KCl:KBr:RbCl:RbB r doped with europium, each component in a 25% molar fraction and 0.5% of E u++, is reported. The value of its refractive index was measured, the cryst allographic properties are characterized by X-ray diffractometry, the optic al properties were studied by optical absorption in UV-VIS region, and by p hotoluminescence under N-2 laser excitation at 12 K and at RT. The diffract ometer diagram of a powder sample shows a single phase and a well defined v alue of the lattice constant. From the optical absorption spectra of europi um, the value of 10 Dq parameter is obtained, the result is in good agreeme nt 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 pres ent in the quenched samples. From obtained data, it is suggested that the s ymmetry of the Eu++ site in the quaternary crystal KCl0.25KBr0.25RbCl0.25Rb Br0.25 is similar to a quenched sample of a single component crystal. (C) 2 001 Elsevier Science B,V. All rights reserved.