Growth and structure of epitaxial CeO2 by oxygen-plasma-assisted molecularbeam epitaxy

The epitaxial growth of CeO2 films on SrTiO3(001) has been investigated ove r a wide range of growth parameters using oxygen-plasma-assisted molecular beam epitaxy. The lattice mismatch for CeO2 on SrTiO3(001) is 2.0% (compres sive) if the film nucleates with a 45 degrees rotation about [001] relative to the substrate (i.e., CeO2(001)\\SrTiO3(001) and CeO2[110]\\SrTiO3[100]) . pure-phase, single-crystalline epitaxial films of CeO2(001) with the abov e epitaxial relationship readily grew on SrTiO3(001) for substrate temperat ures ranging from 550 to 700 degrees C. However, small amounts of (111) and (220) minority orientations also nucleated at the higher substrate tempera tures. In addition, the film surface was observed to become progressively s moother with increasing substrate temperature due to more extensive island agglomeration. The highest-quality him surface grown at 700 degrees C is un reconstructed and oxygen terminated. (C) 1999 American Vacuum Society. [S07 34-2101(99)02903-6].