Ferroelectric nanodomains in epitaxial PbTiO3 films grown on SmScO3 and TbScO3 substrates

TL;DR

This study compares the domain structures of ferroelectric PbTiO3 films grown on two different substrates, revealing substrate-dependent domain orientations linked to lattice mismatch effects.

Contribution

It provides the first detailed comparison of PbTiO3 ferroelectric domain architectures on SmScO3 and TbScO3 substrates using Raman spectroscopy and PFM.

Findings

PbTiO3 on SmScO3 exhibits mainly a-domain orientation.

PbTiO3 on TbScO3 shows predominantly c-domain orientation.

Differences are attributed to lattice mismatch at deposition temperature.

Abstract

Domain structures of 320 nm thin epitaxial films of ferroelectric PbTiO3 grown by MOCVD technique in identical conditions on SmScO3 and TbScO3 perovskite sub- strates have been investigated by Raman spectroscopy and piezoresponse force microscopy techniques. Phonon frequency shifts and typical domain structure motifs are discussed. The results reveal strikingly different domain structure architecture: domain structures of the PbTiO3 film grown on SmScO3 have dominantly a-domain orientation while strongly preferential c-domain orientation was found in the PbTiO3 film grown on the TbScO3 substrate. Differences between the two cases are traced back to the film-substrate lattice mismatch at the deposition temperature.