Ferroelectric enhancement of La-doped BaTiO3 thin films using SrTiO3 buffer layer

Abstract

Pulsed laser deposition (PLD) was used to fabricate La0.01Ba0.99TiO3 (LBTO) thin films on MgO/TiO2/SiO2/Si substrates with and without SrTiO3 (STO) buffer layer. LBTO films deposited on STO layers exhibited enhanced ferroelectricity and decreased leakage current (9 x 10(-7) A/cm(2) at 50 kV/cm), conductivity, and Hall mobility, compared to those of LBTO films on MgO substrate. The remanent polarization (P-r) and coercive field (E-c) for LBTO thin films on STO buffered MgO substrate dramatically improved, 36.5 mu C/cm(2) and similar to 220 kV/cm, compared to those for LBTO thin films on MgO substrate, 3 mu C/cm(2) and similar to 60 kV/cm. The degradation of P-r and E-c after 10(5) switching test is less than 0.1% for LBTO thin films on STO buffered MgO substrate. This work demonstrates a route to a lead-free ferroelectric thin film for nonvolatile memories and electro-optic devices. (C) 2013 Elsevier B.V. All rights reserved.