Local structure and lattice dynamics of cubic Y₂O₃: An x-ray absorption spectroscopy study

Classical molecular dynamics was used to interpret the temperature dependent (300-1273 K) Y K-edge x-ray absorption spectra of cubic c-Y₂O₃ and to validate two force-field models. It was shown that both models reproduce well thermal disorder effect, however are less accurate in description of static octahedra distortion around yttrium atoms. The temperature dependencies of mean-square displacements and mean-square relative displacements were obtained from molecular dynamics simulations for the first two shells of yttrium. The importance of anharmonic effects was demonstrated by comparison of molecular dynamics and lattice dynamics results.