PbTiO3 Thin Films Grown on Pt-covered Vicinal SrTiO3(001) Substrates

We investigated the growth behavior and the domain structure of PbTiO3 thin films grown on Pt-covered SrTiO3 (100) (STO) substrates by metalorganic chemical vapor deposition. The step height and the terrace width of the single-crystalline Pt films on 1 - 4 degrees vicinal STO substrates along the [100] and the [110] directions were 1 - 6 and 80 - 150 nm, respectively. PbTiO3 films were grown in the Volmer-Weber mode on Pt-covered vicinal STO substrates, and nanosized islands were formed at an early growth stage. Atomic force microscopy revealed that nucleation of PbTiO3 predominantly occurred at ascending steps on the Pt surface and that the lateral growth of PbTiO3 islands was limited by the steps. X-ray diffraction analysis and piezoresponse force microscopy indicated that a-domains and misfit dislocations were anisotropically introduced in PbTiO3 thin films on a Pt/4 degrees-vicinal STO substrate along the [100] direction. On [110]-vicinal STO substrates, no significant influence of the vicinal substrate on the growth behavior or the domain structure of PbTiO3 was observed.