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

Abstract : 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.