PIEZOELECTRIC PROPERTIES AND EQUIVALENT-CIRCUITS OF FERROELECTRIC RELAXOR SINGLE-CRYSTALS

Temperature dependent piezoelectric properties of ferroelectric relaxe r single crystals, particularly the cerium-doped strontium barium niob ate compositions (SBN60: Ce), were investigated by resonance and anti- resonance technique. Characteristic resonant frequencies (f(r)-f(a), f (s)-f(p), and f(m)-f(n)) were studied using equivalent circuit simulat ion. Piezoelectric resonance in a relaxer resonator persists into temp eratures much higher than T-m (the temperature at which dielectric con stant, kappa, has a maximum at 1 kHz) in comparison with the normal fe rroelectrics such as TGS. The parameters in an equivalent circuit, how ever, are phenomenally different from a normal resonator like a TGS, n ear and above the transition temperature region. The significance and understanding of the piezoelectric resonance characteristics in ferroe lectric relaxer are discussed.