Crystal orientation dependence of piezoelectric properties of single crystal barium titanate

The dielectric and piezoelectric constants of single crystal barium titanat e have been theoretically calculated and experimentally measured for differ ent cutting orientation directions. The dielectric constant rapidly increas es as the cutting direction deviates away from the unique spontaneous polar ization 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 l arger than its value along the polarization direction. The electromechanica l coupling factor k(33) is also enhanced by choosing a cutting direction ca nted away from the polarization direction. (C) 1999 Elsevier Science B.V. A ll rights reserved.