Characteristics of Pt/PbZr

PbZr0.52Ti0.48O3 (PZT) and YBa2Cu3O7−δ (YBCO) thin films were fabricated by a pulsed laser deposition (PLD) method. The Pt/PZT/Pt ferroelectric capacitors were fabricated on silicon substrates while the Au/PZT/YBCO capacitors were fabricated on LaAlO3 substrates. The capacitance-voltage (C-V) properties and the hysteresis loops of the capacitors were measured before and after γ-ray irradiation. The results show that for Pt/PZT/Pt capacitors, the remanent polarization Pr and the absolute coercive field EC increase while the dielectric constant ε decrease with increasing accumulated dose. For the Au/PZT/YBCO capacitors, Pr and ε decreased with accumulated dose, but the absolute value of the negative and positive coercive fields increased. The results have been interpreted by radiation-induced positive charge trapping at defects in the ferroelectric materials