Tunable enhancement of ferroelectric properties in BaxSr1−xTiO3/La0.7Sr0.3MgO3 heterostructures observed by means of second harmonic generation technique

This work is devoted to research an influence of Ba cation concentration on polarization properties of ferroelectric layer which is included in bilayer structures as functional stratum. We have created bilayer nanocomposites consisting of a ferroelectric Ba(x)Sr(1−x)TiO3 (BST) layer and a ferromagnetic La0.7Sr0.3MnO3 (LSMO) layer with various concentrations of Ba. The epitaxial heterostructure BST/LSMO was fabricated using metal-organic aerosol deposition technique (MAD) on a single-crystal substrate SrTiO3 (001). The structural parameters of the BST/LSMO were defined by X-ray diffraction analysis. The in-plane ferroelectric polarization, measured by means of optical second harmonic generation (SHG) method, was shown to be strongly dependent on the Ba concentration. We consider this effect as structural distortion at room temperatures which close to the structural phase transition and altering the Ba concentration affects the vicinity to the phase transition point.