Characteristics of Pt/PbZr_(0.52)Ti_(0.48)O_3/Pt and Au/PbZr_(0.52)Ti_(0.48)O_3/YBa_2Cu_3O_(7-#delta#) capacitors after #gamma#-ray irradiation

摘要

PbZr_(0.52)Ti_(0.48)O_3 (PZT) and YBa_2Cu_3O_(7-#delta#) (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 LaAlO_3 substrates. The capacitance-voltage (C-V) properties and the hysteresis loops of the capacitors were measured before and after #gamma#-ray irradiation. The results show that for Pt/PZT/Pt capacitors, the remanent polarization p_r and the absolute coercive field Ec increase while the dielectric constant #epsilon# decrease with increasing accumulated dose. For the Au/PZT/YBCO capacitors, P_r and #epsilon# 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.