Ferroelectric and Dielectric Properties of BaTiO₃/Ba_0.30Sr_0.70TiO₃ Superlattices

Abstract

BaTiO3/Ba0.30Sr0.70TiO3 (BT/BST3070) artificial superlattice (SL) was fabricated by pulsed laser deposition on La0.67Sr0.33MnO3 (LSMO) coated (001) MgO substrates. Satellite reflections in X-ray diffraction are used to calculate the periodicity of SL structure indicates a period ∼14 nm. Cross polarized Raman spectra show upward shift of the E(1TO) soft mode, this is markedly changed with respect to its parent BT layer thin film. The BT/BST3070 SL illustrates high dielectric constant (1100-1300) and low loss tangent (<0.1) below to 104 Hz. Polarization and dielectric constant show strong switching behavior under applied external electric field with well saturated hysteresis loop and high dielectric tunability.