X-RAY-ABSORPTION SPECTROSCOPY STUDY OF REO3 LATTICE-DYNAMICS

The lattice dynamics of ReO3 is studied for the first time by x-ray absorption spectroscopy (XAS) in the temperature range from 77 to 350 K at the rhenium L(3) edge. The Debye-Waller factors are extracted for the first, fourth and sixth coordination shells of rhenium, and their temperature dependences are discussed on the basis of the Debye and Einstein vibrational models. The obtained characteristic temperatures Theta(D) and Theta(E) are compared with the ones found by other experimental techniques. The application of the Debye and Einstein models to the analysis of the XAS and x-ray diffraction data for compounds with different degrees of correlation in atomic motion is also discussed.