Structural analysis on in situ high-temperature XRD of corundum

Abstract

Investigation of high-temperature X-ray diffraction is a tool for the characterization of structural parameters of materials. Material characterization at high-temperature is needed for many research and industrial applications. In order to ensure the data quality, thermal exposure inside the chamber must be known well. Corundum is one of the materials that does not undergo a phase change but shows the phenomenon of thermal expansion at low temperatures, so it is very good for testing heat exposure inside the chamber. In this study, we investigated the changes in the corundum structure during heating to find out how the corundum receives heat in the chamber. Particle size characterization was carried out on the corundum to ensure a good X-ray diffraction pattern was obtained. X-ray diffraction measurements using a high-temperature sample stage were carried out at 373, 473, and 573 K. The results showed that the particle size of corundum was in micron size with D50 value at 101.2 μm. The lattice parameters increased during heating. The ratio c/a increases slightly during the process of heating, around 2.73. Changes in lattice parameters showed that thermal expansion occurs. The thermal expansion derived from the X-ray diffraction pattern was lower compared to thermal expansion from the calculation. The difference in this thermal expansion value can indicate that the heat received by the corundum inside the chamber has not reached the intended temperature.