Piezoelectric response of pulsed laser deposited heterostructures PZT/YBCO, PLZT/YBCO

Thin films of lead zirconate titanate (PZT) and La doped lead zirconate titanate (PLZT), coupled to layers of YBa2Cu3O7 (YBCO), were formed by pulsed laser deposition on MgO(100) substrates. Interferometric studies of piezoelectric response of the heterostructures were performed with respect to DC electrical bias and AC measurement frequency. The piezoelectric coefficient demonstrated a hysteresis, consistent with polarization switching and related to residual stress in PZT and PLZT films. A strong increase in the values of piezoelectric coefficient d33 from 15...30 pm/V up to 200...250 pm/V was found in both PZT and PLZT films with decrease in the measurement frequency from 1 kHz to 60 Hz