Pyroelectric and piezoelectric properties of thick PZT films produced by a new sol-gel route

The pyroelectric and piezoelectric properties of thick PZT films processed via a new sol-gel method are being investigated. The films were deposited on gold-coated alumina substrates. The pyroelectric properties are being evaluated using pyrodynamic measurements with either a laser or thermoelectric heat source. The pyroelectric coefficient is obtained from pyroelectric current measurements. The piezoelectric properties are being measured using a laser vibrometer-lock-in amplifier set-up. It is shown that the pyroelectric coefficient obtained with laser heating lies in the range of 108 mu C/m(2) K, whereas heating from the rear of the specimen with the thermoelectric element lead to a value of in the range of 350 mu C/m(2) K, These results are explained in terms through thickness temperature gradients. The piezoelectric displacement amplitude versus applied voltage shows a no-linear behaviour, which is explained in terms of materials chemistry. The maximum effective piezoelectric coefficient, d(33), is obtained as 340 pm/V, and is superior to the values known for ferroelectric thin films. (c) 2005 Elsevier Ltd. All rights reserved.