XAS investigation of Al₂O₃-coated nano-composite ZrO₂

In order to complement the structural characterisation by high resolution electron microscopy and perturbed angular correlation spectroscopy (PAC) of Al₂O₃ coated nano-composite ZrO₂, XAFS spectra have been acquired and analysed. The electron micrographs showed fringes of a well ordered lattice and well defined crystal faces of the as-produced powder whereas the PAC spectra indicated a strongly distorted short range order. On the basis of the XAFS data, a structural model for the ZrO₂ core of the nano-composite ZrO₂/Al₂O₃ with a well ordered Zr lattice and a sevenfold, strongly distorted nearest neighbour oxygen shell is proposed. A smooth temperature dependence without an indication for a phase transformation up to a temperature of 700K has been revealed.