Thermal wave study of piezoelectric coefficient distribution in PMN-PT single crystals

Abstract For Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) single crystals, the measured pyroelectric coefficient (at constant stress) is determined by the piezoelectric effect due to thermal strain (secondary pyroelectric effect). This provides new capabilities to characterise the PMN-PT crystal poling procedure using the thermal square wave method at constant frequency. In this work, the authors demonstrate for the first time the determination of the depth profile of the piezoelectric response of PMN-PT single crystals with a composition near the morphotropic phase boundary by means of thermal waves. A commercial PMNT-28 sample, poled along [001] direction, electroded with NiCr/Au and covered additionally with a black absorption layer was investigated.