Published online by Cambridge University Press: 15 September 1999
PbZr0.52Ti0.48O3 (PZT) and YBa2Cu3O7−δ (YBCO) thin filmswere 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) propertiesand the hysteresis loops of the capacitors were measured before and after γ-rayirradiation. The results show that for Pt/PZT/Pt capacitors, the remanent polarizationP r and the absolute coercive field E C increase while the dielectricconstant ε decrease with increasing accumulated dose. For the Au/PZT/YBCOcapacitors, P r and ε decreased with accumulated dose, but theabsolute value of the negative and positive coercive fields increased. The resultshave been interpreted by radiation-induced positive charge trapping at defects in theferroelectric materials.