A comparative analysis of lattice dynamic peculiarities in barium titanate structures via Raman spectroscopy

Abstract

This work is aimed at investigating three types of barium titanate materials (single crystal as a bulk system, epitaxial film and BaTiO3/SrTiO3 (BT/ST) superlattice as the nanostructures), using in situ Raman spectroscopy in a wide range of temperatures (from 80 to 500 K) as an experimental tool. Special attention is paid to strain-sensitive A1(2TO) and E(1TO) soft mode components, which temperature evolution is carefully monitored in order to furnish information about phase transition sequences for each of these structures. It is established that, while the single crystal exhibits the typical T–O–R phase transformation of the bulk BT within a specified temperature range, the nanostructured epitaxial film and superlattice drastically deviate from that sequence.