Structural changes of titanium oxide films, formed by evaporating TiO1.0 on NaCl substrates held at various temperatures, were studied during in situ heating in an electron microscope. It was revealed that the evaporant decomposes partially into titanium and oxygen ions during the evaporation. As‐deposited films composed of both hexagonal‐close‐packed and NaCl‐type crystallites were oxidized by heating at about 600C and the crystal structures of the film transform finally into the transition structure I in which titanium vacancies were ordered. On the way toward the transformation, crystals of the transition structure II in which oxygen vacancies were ordered, grow and the δ‐phase single crystals (ad = 4.98Å, cd = 2.89Å) precipitate also. On the basis of the examination of the structural relationship between the δ‐phase and the hcp α‐phase crystals, the former crystals were considered to be grown from the latter crystallites. The distortion of the transition structure I and II from the parent NaCl‐type lattice was also discussed. 

Structural Change of Titanium Oxide Evaporated Films during in situ Heating in an Electron Microscope. Yamada, Y., Shiota, I., Yoshida, K.: Journal of Vacuum Science & Technology A, 1993, 11[5], 2642-8