Effects of chloride ion in teo2-zno-zncl2-li 2o-eu2o3 glass system

Abstract

A series of zinc oxychloride tellurite glass based on (79 – z) TeO2 - 10ZnO - (z) ZnCl2 - 10Li2O - 1Eu2O3 (where z = 0, 10, 20, 25 and 30 mol %) are successfully prepared by the melt quenching method. The optical properties are characterized by means of Raman spectra, UV-Vis and photoluminescence spectroscopy. It is found that the Raman spectrum of the glass shows three main peaks in the vibrational band in the vicinity of 430, 670 and 770 cm-1. The intensity of all bands is decreased as the ZnCl2 contents are increased from 0 to 30 mol % but the intensity ratio (I770 / I670) increased. This may arise from the change in the structural chains from TeO4 to TeO3+1 or to a TeO3 polyhedron shape. Using the UV-Vis absorption spectrum, the Judd-Ofelt (J-O) analysis is performed to determine the J-O parameters (Ω2, Ω4, Ω6) and it is found that Ω2 > Ω4 > Ω6. The values of Ω2, Ω4 , Ω6, the quality factor (Q) and the radiative lifetime (τrad) are found to increase with ZnCl2 content up to 20 mol %. From photoluminescence spectrum, it is found that the value of the intensity ratio between 5D0 →7F2 and 5D0 →7F1 transition increase with ZnCl2 contents which illustrates that this glass can easily become laser material.