Oxygen vacancy as fatigue evidence of La_0.5Sr_0.5CoO₃/PbZr_0.4Ti_0.6O₃/La_0.5Sr_0.5CoO₃ capacitors

B. T. Liu^1a, J. E. Chen^1,2, J. Sun^1,2, D. Y. Wei¹, J. H. Chen¹, X. H. Li¹, F. Bian¹, Y. Zhou¹, J. X. Guo¹, Q. X. Zhao¹, L. Guan¹, Y. L. Wang¹, Q. L. Guo¹ and L. X. Ma³

¹ College of Physics Science & Technology, Hebei University - Hebei 071002, China
² College of Electronic and Information Engineering, Hebei University - Hebei 071002, China
³ Department of Physics, Blinn College - Bryan, TX 77805, USA

^a btliu@hbu.cn

Received: 17 June 2010
Accepted: 10 September 2010

Abstract

La_0.5Sr_0.5CoO₃ (LSCO) films grown on SrTiO₃ substrates, cooled at reduced oxygen pressures, ranging from 8×10⁴ to 1×10⁻⁴ Pa, from the depostion temperature, are used as the bottom electrodes of PbZr_0.4Ti_0.6O₃ (PZT) capacitors to study the impact of oxygen stoichiometry of the LSCO bottom electrodes on the structural and physical properties of LSCO/PZT/LSCO capacitors. It is found that the tetragonality, polarization and fatigue-resistance of PZT films decrease with the decrease of the cooling oxygen pressure. Almost 60% polarization degradation occurs for the PZT capacitor with the LSCO bottom electrode cooled in 1×10⁻⁴ Pa oxygen up to 10¹⁰ switching cycles, indicating that the oxygen vacancy of the bottom electrode can result in fatigue of the LSCO/PZT/LSCO capacitor.