A Comparative Analysis of Asymmetric (BaTiO3)‎ 1−xΛ(BaZrO3)‎xΛ Superlattices via X-Ray Diffraction and Raman Spectroscopy

Abstract EN

This work is aimed at studying asymmetric BaTiO31 − xΛ/BaZrO3xΛ ((BT) 1−xΛ/(BZ)xΛ) superlattices, grown by pulsed laser deposition onto (001) MgO substrates.

The thicknesses of BT (ferroelectric) and BZ (paraelectric) layers were varied so that х ranged from 0 to 1 at a modulation period Λ of about 80 Å.

The films were 400 nm thick.

The out-of-plane lattice parameters of constituents were assessed using X-ray diffraction.

The lattice dynamic peculiarities of superlattices were probed via Raman spectroscopy; special attention is paid to the analysis of E(1TO) and A1(2TO) ferroelectric soft modes.

A comparative analysis of data acquired via both experimental techniques reveals the enhancement of stress between BT and BZ layers with a decrease in symmetry from the tetragonal to a monoclinic phase due to strains induced by the lattice parameter mismatch between the constituents.