A relaxor ferroelectric single crystal cut resulting in large d312 and zero d311 for a shear mode accelerometer and related applications
Relaxor ferroelectric single crystals exhibit anisotropic piezoelectric behavior. This enables the use of a combination of crystal cut and poling to obtain piezoelectric properties optimized for certain applications. This work describes a crystal cut that is optimized for applications where a strong face shear mode d 312 coupling is desired with a zero d 311 or zero d 322 piezoelectric coefficient. Such a crystal cut enables the production of stack actuators in a long bar shape with the electric field perpendicular to the bar length. These bars can be cantilevered with a mass at the end to produce a highly sensitive shear mode accelerometer. The zero value of d 311 or d 322 eliminates a possible extensional mode coupling along the length of the bar. Only one of d 311 or d 322 can be made equal to zero, the other having a negative value. 2012 IOP Publishing Ltd.