Local Piezoelectric Hysteresis Loops for the Study of Electrical Properties of 0.7Pb(Mg_1/3Nb_{2/ 3})O₃-0.3PbTiO₃ Thin Films: Bottom Electrode Dependence and Film Thickness Effect

Abstract

0.7Pb(Mg _1/3 Nb _2/3 )O ₃ –0.3PbTiO ₃ (PMN–PT 70/30) thin films, 400 and 600 nm thick, have been grown on Pt and LaNiO ₃ (LNO) bottom electrodes by rf magnetron sputtering. For each thickness, local piezoelectric hysteresis loops evidence that the individual PMN-PT grains deposited on LNO always require much higher voltage than the ones grown on Pt for switching. The average piezoelectric activity of grains is shown to be the highest for LNO electrode. For each electrode, film thickness has no significantly effect on the average coercive voltage and piezoelectric activity measured on the loops. A simple charge model explains this result.

Keywords:

• PMN–PT thin films
• Pt and LNO bottom electrodes
• nanoscale investigations
• atomic force microscopy
• local piezoelectric hysteresis loops

Acknowledgments

A. Ferri is grateful to the Nord-Pas de Calais region for its financial support to carry out this work. The authors of LPCIA wish to acknowledge L. Maës for technical support.