Diffraction, structure and phase stability studies on aluminium titanate

Abstract

The crystal structure studies of aluminium titanate (Al 2TiO 5) in the temperature range of 25–1200 °C have been investigated by X-ray and neutron powder diffraction. The use of simultaneous refinement of the X-ray and neutron data has enhanced the refinement precision of the structure model of Al 2TiO 5 with the concomitant improvement in values such as atomic coordinates, site occupancies and unit-cell parameters. Results from Rietveld refinements showed that the disordering of Ti and Al atoms in the metal 1 and metal 2 sites. High-temperature neutron diffraction studies of the Al 2TiO 5 crystal structure revealed an increasing substitution of Al for the Ti atoms in the crystal structure. It is proposed that this increased substitution is responsible for the decomposition of Al 2TiO 5 that is observed between 900 and 1280 °C.