High energy oxygen ion induced modifications in lead based perovskite thin films

Abstract

The lead based ferroelectric PbZr_0.53Ti_0.47O₃ (PZT), (Pb_0.90La_0.10)TiO₃ (PLT10) and (Pb_0.80La_0.20)TiO₃ (PLT20) thin films, prepared by pulsed laser ablation technique, were studied for their response to the 70 MeV oxygen ion irradiation. The dielectric analysis, capacitance-voltage (C-V) and DC leakage current measurements were performed before and after the irradiation to high-energy oxygen ions. The irradiation produced considerable changes in the dielectric, C-V, leakage characteristics and induced some amount of amorphization. The PZT films showed partial recrystallization after a thermal annealing at 400 °C for 10 min. The phase transition temperature [T_c] of PLT20 increased from 115 °C to 120 °C. The DC conductivity measurements showed a shift in the onset of non-linear conduction region. The current density decreased by two orders of magnitude after irradiation. After annealing the irradiated films at a temperature of 400 °C for 10 min, the films partially regained the dielectric and electrical properties. The results are discussed in terms of the irradiation-induced amorphization, the pinning of the ferroelectric domains by trapped charges and the thermal annealing of the defects generated during the irradiation.