In-plane aligned CeO2 films grown on amorphous SiO2 substrates by ion-beam assisted pulsed laser deposition

Both (001)- and (111)-oriented CeO2 thin films have been grown on amorphous fused silica (SiO2) substrates by ion-beam assisted pulsed laser ablation of a polycrystalline CeO2 target. Using 200 eV Ar+ ions incident at 55° to the substrate normal, the preferred orientation for CeO2 film growth is (001) at room temperature, but changes to (111) for temperatures ≥300 °C. Furthermore, the ion-beam assisted CeO2 films exhibit strong in-plane crystallographic alignment. In contrast, CeO2 films grown without ion-beam assistance exhibit a mixture of polycrystalline orientations with the relative amounts depending on growth temperature. Under optimum conditions, off-normal-incidence Ar+ ions produce a (111)-oriented crystalline CeO2 film that is aligned with respect to a single in-plane axis, on an amorphous substrate.