Analysis of shape effects on the piezoresponse in ferroelectric nanograins with and without adsorbates

Using BaTiO3 as a piezoelectric model system we compare a finite element model with experimental data to demonstrate the impact of grain topography on the in-plane piezoelectric response at the perimeter. Our findings emphasize the need for a careful consideration of both electric field and piezoelectric tensor orientation. An analysis is given showing that the in-plane piezoresponse is a function of two directions of the electric field, whereas the out-of-plane response is a function of all three directions of the applied field. The effect of an adsorbate layer on the piezoelectric response is quantified with typical material parameters. (c) 2005 American Institute of Physics