Intrinsic dead layer effects in relaxed epitaxial BaTiO3 thin film grown by pulsed laser deposition

Epitaxial BaTiO3 (BT) thin film of about 400 nm thickness was grown on LaSr0.5Co0.5O3 (LSCO) coated (001)MgO using pulsed laser deposition. Ferroelectric properties of the BT thin film in Pt/BVISCO/MgO heterostructure capacitor configuration were investigated. Dynamic P-E hysteresis loops at room temperature showed ferroelectric behavior with P-s = 32 mu C/cm(2), P-r = 14 mu C/cm(2) and E-c = 65 kV/cm. Static C-V measurements confirmed reversible switching with a coercive field E-c = 15 kV/cm. Basing on a model taking into account an interface dead-layer we show that the capacitance-voltage butterfly loops imply only 25% switching of dipoles that inferred from dynamic polarization-field loops (similar to 4 and similar to 16 kV/cm, respectively). Dielectric permittivity as a function of temperature revealed a first-order ferroelectric-to-paraelectric (FE-PE) phase transition in the BT film characterized by a maximum at T-c similar to 130 degrees C. The very large (similar to 126 K at 1 kHz) difference between T-c and the extrapolated Curie Weiss temperature T-o is attributed to the dead-layer effects. (C) 2017 Elsevier Ltd. All rights reserved.