Nanoscale domain engineering in SrRuO3 thin films

Abstract

We investigate nanoscale domain engineering via epitaxial coupling in a set of SrRuO3/PbTiO3/SrRuO3 heterostructures epitaxially grown on (110)o-oriented DyScO3 substrates. The SrRuO3 layer thickness is kept at 55 unit cells, whereas the PbTiO3 layer is grown to thicknesses of 23, 45, and 90 unit cells. Through a combination of atomic force microscopy, x-ray diffraction, and high resolution scanning transmission electron microscopy studies, we find that above a certain critical thickness of the ferroelectric layer, the large structural distortions associated with the ferroelastic domains propagate through the top SrRuO3 layer, locally modifying the orientation of the orthorhombic SrRuO3 and creating a modulated structure that extends beyond the ferroelectric layer boundaries.