Atomic scale investigation of a PbTiO_3/SrRuO_3/DyScO_3 heterostructure

摘要

An epitaxial PbTiO_3 thin film grown on self-organized crystalline SrRuO_3 nanowires deposited on a DyScO_3 substrate with ordered DyO and ScO_2 chemical terminations is investigated by transmission electron microscopy. In this PbTiO_3/SrRuO_3/DyScO_3 heterostructure, the SrRuO_3 nanowires are assumed to grow on only one type of substrate termination. Here, we report on the structure, morphology, and chemical composition analysis of this heterostructure. Electron energy loss spectroscopy reveals the exact termination sequence in this complex structure. The energy loss near-edge structure of the Ti-L_(2,3), Sc-L_(2,3), and O K edges shows intrinsic interfacial electronic reconstruction. Furthermore, PbTiO_3 domain walls are observed to start at the end of the nanowires resulting in atomic steps on the film surface.