Optical and devitrification kinetic studies of chloro-antimonate glasses
Résumé
In this present work optical and devitrification studies of the synthesized 80 Sb2O3 –10 SrCl2 – 10 CdCl2 glasses were explored. The samples were annealed at temperature 455 °C by the different time range from 10 to 25 min with an interval of 5 min. All the synthesized samples have been characterized by spectroscopic techniques viz., UV–visible transmission, Fourier Transform Infrared transmission and Urbach plot was the complementary for the optical band gap calculation, finally the refractive index of the glass sample has been determined. The synthesized glass sample has a large optical window operating between 361 nm and 7.51 μm and has a high refractive index close to 1.7. The Urbach's plot shows that the optical band gap of the glass sample reaches a higher order value 3.25 eV. Scanning electron microscope (SEM) examination confirms that devitrification obeyed superficial mechanism, when controlled by the specific pre-nucleation process, which is based on self-creation of rough areas and the crystallization diffusion depth. On surface crystals formed in different morphologies like polyhedron; hemispherical (rarely); lath and needle. The progression of crystallization towards the interior is done layer by layer mode (nested lamellae) whereas the contour of the assembly is in a root mode. X-ray diffraction (XRD) pattern shows that the crystalline structure is composed of Valentenite. The kinetic parameters such as crystallization energy (150 kJ/mol) and the Avrami's (n = 3.405) index were calculated according to Chen's and Ozawa's methods. The attractive optical qualities and kinetic parameters indicate that the synthesized glass sample is a good stability against devitrification. © 2020 Elsevier B.V.