INVESTIGATIONS OF ATOMIC DISORDER AND GRAIN GROWTH KINETICS IN POLYCRYSTALLINE Gd2Ti2O7

Abstract

Pyrochlores are used for a variety of purposes, including luminescence, ionic conductivity, superconductivity, high temperature thermal battery coatings, nuclear waste immobilization, electrocatalyst, automobile exhaust gas control, electrocatalyst, solid oxide fuel cell, magnetoresistance and many more. The main focus of this study was to examine how the annealing temperature & duration is influencing atomic order/disorder & growth of grains in the pyrochlore Gd2Ti2O7. Results indicate that the sample stays in the pyrochlore phase for a relatively longer time at very high annealing temperatures. Designing pyrochlore materials for diverse energy applications may benefit from understanding how atomic order/disorder and grain development affect structural characteristics. The solid state route was used to produce Gd2Ti2O7 via uniform heating at distinct temperature level (1100, 1200, and 1300°C) in different time periods (24h & 43h). X-ray diffraction (XRD), Raman spectroscopy, and Scanning electron microscopy (SEM) characterization techniques were performed in order to study both structural & microstructural characteristics associated with Gd2Ti2O7. With a rise in heating temperature and time, there is a greater degree of cation-anion order. The production of bigger grains was preferred over coarsening of small grains by curvature. Hence, Gd2Ti2O7 grains gradually expand as the heating period and temperature are raised. According to XRD and Raman spectroscopy, grain expansion largely influences the system’s periodic ordering through a relaxation iv through a of the microstrain and the rise in crystallite size, but there is no discernible impact on the structural ordering, particularly on anion lattice. In order to examine the cation/anion ordering & microstructural changes in pure phase polycrystalline Gd2Ti2O7 , a quantitative analysis has been given. Therefore, pure phasic GTO has been successfully created using the solid-state reaction method, which was then followed by numerous grinding and heating protocols, and it can now be applied in a variety of fields.