Elastic and Anelastic Behavior of the Relaxor Ferroelectric 0.55SrTiO₃-0.45BiScO₃

Abstract

Elastic and anelastic properties of the relaxor 0.55SrTiO 3 -0.45BiScO 3 ceramics were studied. Anomalous behavior of the Young's modulus and the internal friction were observed at cooling below the Burns temperature T d ≈585 K. Both elastic and anelastic anomalies were found to be frequency dependent. Elastic softening is assumed to be due to an electrostriction relationship between spontaneous polarization of polar tetragonal nanoclusters and a strain of unit cell. It was found that the internal friction anomaly observed below T d is in fact superposition of two maxima. Higher temperature maximum is typical for relaxors. Using the special internal friction mechanism for the first order phase transition, the size of the polar tetragonal nanoclusters was estimated to be equal to ∼10 nm. Such sizes of tetragonal islands were found for the sample under study by using the electron backscattered diffraction method.

Elastic Properties and Enhanced Piezoelectric Response at Morphotropic Phase Boundaries

“…In relaxors, the PNR, therefore , interact with stress thanks to the electrostrictive coupling , Equation ( 27 ) and produce softening [ 99 , 100 , 101 ]. This can be seen using the Slonczewski and Thomas [ 89 ] derivation of the elastic anomaly at a phase transition, that is alternative to Section 5.1 but gives the same result.…”