Microstructural characterization and crystallization of (1 − x)TeO 2– xCdF 2 ( x = 0.10, 0.15, 0.25 mol) glasses

Abstract

The differential thermal analysis (DTA), X-ray diffractometer and scanning electron microscopy/energy dispersive spectrometer (SEM/EDS) techniques were used to investigate the microstructural characterization and the thermal behavior of the three (1 − x)TeO 2– xCdF 2 ( x = 0.10, 0.15, 0.25 mol) glasses. The effect of the heating rate, annealing temperature and CdF 2 content on the thermal and the microstructural properties of TeO 2–CdF 2 binary glasses were enquired. DTA analysis has shown that as the CdF 2 content in the glass composition increases, the value of the glass transition and the peak crystallization temperatures shift to higher values. SEM/EDS investigations have shown that the crystal formation of α-TeO 2, γ-TeO 2 and CdTe 2O 5 crystal phases were observed when the 0.90TeO 2–0.10CdF 2 and the 0.85TeO 2–0.15CdF 2 glass samples were annealed to temperatures above the crystallization temperatures. X-ray diffraction (XRD) results illustrated clearly the transformation of the metastable γ-TeO 2 phase to stable α-TeO 2 crystalline phase as the annealing temperature was increased from 385 to 425 °C for the 0.75TeO 2–0.25CdF 2 glass.