Structure of epitaxial thin TiOx films on W(110) as studied by low energy electron diffraction and scanning tunneling microscopy

We have studied the growth and structure of thin TiOx films on W(110) using Auger electron spectroscopy, low energy electron diffraction (LEED), and scanning tunneling microscopy (STM). The procedure used to grow these films includes the deposition of Ti metal onto the W(110) surface followed by a saturation oxygen exposure. LEED and STM reveal that several different ordered TiOx film structures can result depending upon the initial amount of Ti deposited and the final annealing temperature. Specifically, the oxidation and anneal to 1350 K of a one monolayer (ML) film of Ti resulted in the formation of a strained ML structure that has a distorted hexagonal lattice and long-range order as observed by LEED and STM. The epitaxial relationship of this 1 ML TiOx structure with the W(110) substrate is found to occur with a Nishiyama endash Wassermann orientation. copyright 1996 American Vacuum Society