Local structure studies of magnesium titanate powders using time-resolved X-ray absorption spectroscopy (TRXAS) measurements

Abstract

The studies of the evolution of the local atomic environment of magnesium titanate powders under thermodynamic conditions were reported through time-resolved x-ray absorption spectroscopy (TRXAS) measurements. The powders were prepared by a dissolved metals mixing method. The stoichiometric Mg and Zn metal powders were independently dissolved in hydrochloric acid solution, followed by mixing, drying, and pre-calcination at 400 °C. The changes of local structure of the systems during thermodynamic conditions were examined using TRXAS in Ti K-edge XANES spectrum by in-situ measurement at room temperature until 700 °C. XANES spectrum analysis was carried out by fitting process using a Gaussian convolution function. The interpretation of absorption peaks in Ti K-edge XANES spectrum is related to the transition of electrons from the Ti 1s state to the higher energy levels. The dependence of the peak position and intensity on the ambient temperature due to the changes of the local atomic environment of Ti has also been observed.