Abstract
SrTiO3 (STO) is the most frequently used substrate material for complex oxide films. In this work, STO is explored as a buffer layer on piezoelectric pseudocubic Pb(Mg1/3Nb2/3)0.72Ti0.28O3(001) (PMN-PT) substrates which serve to reversibly strain thin films. The STO buffer layer reduces the in-plane lattice parameter and allows for better lattice matching to broader range of thin film materials. STO films (30 nm) have been grown with epitaxial orientation on PMN-PT with an in-plane lattice parameter close to that of bulk STO. The substrate`s rhombohedral domain structure has been imaged by Atomic Force Microscopy (AFM). The related ferroelectric domain structure has been investigated by Piezoresponse Force Microscopy (PFM). Within a domain, STO grows with rather low roughness (rms < 0.2 nm). The transfer of the piezoelectric substrate strain to the STO film and its variation with an applied electric field is studied by x-ray diffraction. The strain dependence of the electrical resistance is measured for a ferromagnetic manganite film grown on top of the STO. Both experiments confirm qualitatively that the STO buffer transfers the substrate strain into a functional film deposited on top.
