Anisotropic ferro- and piezoelectric properties of sol-gel-grown Bi3.15Nd0.85Ti3O12 films with two different orientations on Pt/Ti/SiO2/Si

Bi3.15Nd0.85Ti3O12 thin films of two different preferred orientations were sol-gel grown on Pt/Ti/SiO2/Si. Using different heating rates during crystallization, either films containing 65% columnar grains with (104)/(014) orientation or fine-grained films with a predominant c-axis orientation were obtained. Anisotropic ferroelectric and piezoelectric properties were determined, with a remanent polarization 2P(r)=46.4 mu C/cm(2) and a piezoelectric coefficient d(33)=17 pm/V in a predominantly (104)/(014)-oriented film, but only 2P(r)=16.7 mu C/cm(2) and d(33)=5 pm/V in a predominantly c-axis-oriented film. These values confirm that the polarization vector of this material is close to the crystallographic a axis. (c) 2006 American Institute of Physics.