RHEED study of the growth of cerium oxide on Cu(1 1 1)

This article reports RHEED and XPS studies of the growth of epitaxial cerium oxide layers on (1 1 1) surface of copper single-crystal. The layers were prepared by reactive evaporation of cerium in 5 × 10−5 Pa of oxygen at different substrate temperatures. Cerium oxide layers exhibited (1 1 1) crystallographic plane parallel to the substrate surface. The model of CeO2(1 1 1)/Cu(1 1 1) epitaxial system is proposed. Morphological parameters of cerium oxide layer were deduced from RHEED diffraction patterns. It was found that average island size increased with the substrate temperature during the deposition. The obtained results are in agreement with the similar studies performed by STM. An experimental arrangement of the RHEED technique permitted to measure an evolution of lattice parameter of cerium oxide during the growth. A contraction of crystal lattice was observed especially in early stages of the growth. XPS measurements indicated the growth of stoichiometric cerium oxide.