Epitaxial growth of Y2O3:Eu thin films on LaAlO3

We report the epitaxial growth of europium-activated yttrium oxide $({\mathrm{Y}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}\mathrm{:Eu})$ (001) thin films on ${\mathrm{LaAlO}}_{\mathrm{3}}$ (001) using laser ablation deposition at a substrate temperature of 775 °C and 10 Hz pulse repetition rate. The orientation relationship between the films and the substrates is ${\mathrm{[110]Y}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}{\mathrm{\parallel [100]LaAlO}}_{\mathrm{3}}$ and ${\mathrm{[-110]Y}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}{\mathrm{\parallel [010]LaAlO}}_{\mathrm{3}}$ which results in a lattice mismatch of only 0.8%. Transmission electron microscopy (TEM) of the films reveals the single crystalline ${\mathrm{Y}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}\mathrm{:Eu}$ thin film to contain small pores. Scanning transmission electron microscopy (STEM) imaging of the films shows the substrate always terminates with the Al sublattice. Moreover, the STEM reveals that no precipitates of Eu had formed in the films.