Links between piezoelectric properties and figures of merit in novel 2–1–2 composites with lead-free ferroelectric components

Important links between piezoelectric coefficients and energy-harvesting figures of merit are studied in novel 2–1–2 composites with two ferroelectric components ([001]-poled single crystals and ceramics), which are chosen among alkali niobates-tantalates. Effective parameters of the related composites are compared. High piezoelectric sensitivity ( g 33 *> 200 mV . m/N) promotes the large figure of merit ( Q 33 *) 2 = d 33 * g 33 *∼10 −10 Pa −1 . An orientation effect caused by rotations of ceramic rod bases in the polymer medium leads to variations of an anisotropy of the piezoelectric coefficients d 3 j * and g 3 j * and fi g ures of merit ( Q 3 j *) 2 , which can be of value in sensor and energy-harvesting applications.