Epitaxial control of polar order in perovskites

Theoretically suggested concept of inducing or enhancing ferroelectric polarization in epitaxial strained films of perovskite structure oxides has been dominating over more than a decade. Unexpectedly, strain induced or enhanced relaxor behavior with the short-range polar order is often observed instead of the ferroelectric order.  In attempt to resolve this contradiction, we study epitaxial films of quantum paraelectrics, ferroelectrics, and relaxors. Recent results will be presented and discussed.