Crystal orientation dependence of piezoelectric properties of single crystal barium titanate

The dielectric and piezoelectric constants of single crystal barium titanate have been theoretically calculated and experimentally measured for different cutting orientation directions. The dielectric constant rapidly increases as the cutting direction deviates away from the unique spontaneous polarization direction [001]. The effective piezoelectric strain constant d(33) exhibits the same trend in the range from 0 degrees to 50 degrees away from the polarization direction and has the maximum value more than 3.5 times larger than its value along the polarization direction. The electromechanical coupling factor k(33) is also enhanced by choosing a cutting direction canted away from the polarization direction. (C) 1999 Elsevier Science B.V. All rights reserved.