@ARTICLE{10.21494/ISTE.OP.2018.0261, TITLE={Evolution of the crystallite size of Erbium Tetrapolyphosphate with heat treatment or oxidation}, AUTHOR={Khalil El-Hami, Mohammed Eddya, Bouazza Tbib, }, JOURNAL={Uncertainties and Reliability of Multiphysical Systems}, VOLUME={2}, NUMBER={Issue 1}, YEAR={2018}, URL={https://openscience.fr/Evolution-of-the-crystallite-size-of-Erbium-Tetrapolyphosphate-with-heat}, DOI={10.21494/ISTE.OP.2018.0261}, ISSN={2514-569X}, ABSTRACT={Our study focuses on the influence of the oxidation temperature on the crystallite size, oxidation kinetics and mechanisms associated with the oxidation of Erbium Tetrapolyphosphate (TPE). We compared the evolution of the crystallographic morphology of the TPE powder subjected to a heat treatment at high temperature between 200 ° C and 1100 ° C. The evolution of the crystallite size of the powder was demonstrated by X-rays diffraction. The structural units of phosphate-based glass were assessed from Raman spectra as TPE; the results show the decomposition of powder in the temperature range of 850° -1100°C. Er3+ absorption spectra were measured in the range of 400-800 nm. Optical bandgap (Eg) were determined using Tauc’s relationship for direct transitions.}}