Thermal expansion of CaIrO3 post-perovskite determined by time-of-flight measurements

Abstract

The thermal evolution of the CaIrO3 post-perovskite structure has been determined by neutron powder diffraction (time-of-flight) measurements in a wide temperature range, from 1.8K to 550K. The linear expansion is similar to that found in previous x-ray diffraction studies, being αb > αc > αa,. However, the difference in relative lattice parameters is less pronounced in the present case, suggesting a more isotropic evolution under temperature. Other structural differences found at low and high temperatures through several X-ray and neutron diffraction studies have been also analysed.