Domain structure of PbTiO3 films grown on vicinal (001) SrTiO3

Epitaxial PbTiO₃ films have been grown on vicinal (001) SrTiO₃ substrates by pulsed laser deposition. Vicinal SrTiO ₃ substrates with misorientations up to 9° from (001) were used and the influence of the direction of misorientation on the resulting domain structure was studied. 4-circle x-ray diffraction analysis indicates that thin (40 nm) PbTiO₃ films are completely c-axis oriented (rocking curve FWHM of 0.25° for the 002 reflection) and that thicker films (~200 nm) contain mixed a-axis and c-axis PbTiO₃ domains due to twinning along {011} planes. The [100] axis of the a-axis domains are misoriented by 2.1° to 3.3° toward ⟨100⟩ substrate directions with respect to the [001] axis of the c-axis domains. In contrast to growth on well-oriented (001) SrTiO₃ surfaces where the four equivalent tilts of the [100] axis of the a-axis domains are equally likely, on vicinal SrTiO₃ the a-axis domains are preferentially oriented in an uphill direction with respect to the crystallographic miscut