X-ray studies of the stoichiometrically prepareda-Ga2Se3 and Ga2Te3 are reported after various stages of air-oxidation in the temperature ranges 250 to 825° C and 250 to 650° C respectively. Diffractometric powder data of Ga2Te3 are also reported over the complete 2ϑ range with remarkable difference in the relative intensities of the (444) and (642) reflections. Ina-Ga2Se3 the oxidation proceeds by formation of the most stable phase, beta-gallium sesquioxide, complete oxidation occurring at 650° C. For Ga2Te3 a mixture of Ga2TeO6 and TeO2 is obtained as the intermediate oxidation products in the range 500 to 600° C, while at 450° C some extra lines which could be indexed on the super-lattice cell of Ga2Te3, along with Te and unchanged Ga2Te3 lines, are observed. Oxidation at the higher temperature of 650° C led to the disappearance of TeO2 lines leaving Ga2TeO6 as the final well-crystallised phase.
Volume 43, 2020
Continuous Article Publishing mode
Click here for Editorial Note on CAP Mode