Characterisation of Y2O3 thin films deposited by laser ablation on MgO: why a biaxial epitaxy

Yttrium oxide, Y2O3, thin films are deposited in situ at 700 °C by laser ablation on MgO substrate. Orientation relationships are studied by means of asymmetric X-ray diffraction and HRTEM investigations. A particular attention is paid to the growth of the (1 0 0) orientation of the oxide which seems to be strongly related to the oxygen partial pressure in the deposition chamber. An explanation in terms of a particular dislocation configuration is proposed. This configuration is linked to the oxygen partial pressure through the atom mobility in the thin oxide film.