Domain controlled piezoelectric single crystal and fabrication method therefor

摘要

A domain controlled piezoelectric single crystal having an electromechanical coupling factor k 33 ‰¥ 80% in a longitudinal vibration mode and a piezoelectric constant d 33 ‰¥ 800 pC/N, comprising an electromechanical coupling factor k 31 ‰¤ 30% in a lateral vibration mode in a direction perpendicular to the polarization direction, a piezoelectric constant -d 31 ‰¤ 300 pC/N and a frequency constant fc 31 (= fr·L) ‰¥ 800 Hz·m which is a product of a resonance frequency fr in the lateral vibration mode relating to k 31 and a length L of the piezoelectric single crystal in a vibration direction.