Chemistry and structure of BaTiO3 ultra-thin films grown by different O2 plasma power

J.L. Wang (1) , J. Leroy (1) , G. Niu (2) , G. Saint-Girons (2) , B. Gautier (3) , B. Vilquin (2) , N. Barrett (1)

1 LENSIS - Laboratoire d'Etude des NanoStructures et Imagerie de Surface
2 INL - H&N - INL - Hétéroepitaxie et Nanostructures
3 INL - DE - INL - Dispositifs Electroniques

We present a study of the chemical and atomic properties of 5 nm TiO2-terminated BaTiO3 (001) epitaxialfilms on Nb-doped SrTiO3, as a function of the atomic oxygen plasma power for film growth. Lowerplasma power produces non-stoichiometric films with oxygen vacancies and Ti3+ ions. The larger Ti3+ion radius and the in-plane clamping gives rise to an increase in the out-of-plane lattice parameter.XPS measures the Ti3+ concentration and the concomitant increase in dissociative water uptake in thefilm, giving rise to on-top OH adsorption on surface Ti, proton adsorption on surface oxygen, and a nearsurface Ba-OH environment.

Domains: Physics [physics]

J.L. Wang, J. Leroy, G. Niu, G. Saint-Girons, B. Gautier, et al.. Chemistry and structure of BaTiO3 ultra-thin films grown by different O2 plasma power. Chemical Physics Letters, 2014, 592, pp.206 - 210. ⟨10.1016/j.cplett.2013.12.030⟩. ⟨cea-01376789⟩