Dielectric hysteresis from transverse electric fields in lead zirconate titanate thin films

Excellent symmetric dielectric hysteresis is observed from lead zirconate t itanate (PZT) thin films using transverse electric fields driven by interdi gitated surface electrodes. The 1-mu m-thick PZT films with a Zr/Ti ratio o f 52/48 are prepared on ZrO2 buffered, 4-in.-diam silicon wafers with a the rmally grown SiO2 layer. Both the ZrO2 buffer layer and PZT film are deposi ted by using a similar sol-gel processing. Remanent polarization of about 2 0 mu C/cm(2) with coercive field less than 40 kV/cm is obtained as measured using a triangle wave at 50 Hz. Thicker films are being developed and rete ntion for the transversely polarized state is currently under study. One of the objectives of this study is to develop a large array of d(33)-driven u nimorph sensing elements for a high-resolution acoustic imaging system. (C) 1999 American Institute of Physics. [S0003-6951(99)03123-X].