Abstract
The domain patterns of (Ba, Sr)TiO3 thin epitaxial films were studied by replica technique with respect to the degree of crystal structure perfection. With increasing the structure defects density numerically estimated by microstrain values, the transition to a relaxor-like microstructure occurred. It seems that the diffusivity of ferroelectric phase transition and other specific features characteristic of thin films of classic ferroelectrics, could be attributed to a co-existence of ferroelectric and relaxor phases in film volume.