Favorable dynamics of switching and non-switching polarizations in ⟨001⟩pc oriented Sm:PMN-PT crystal

Abstract

In this investigation, the dynamic behavior of the switching and the non-switching polarization loops has been studied for ⟨001⟩pc oriented PMN-PT and Sm:PMN-PT crystals. A five-pulse triangular wave sequence was employed to measure the switching and non-switching polarization loops separately as a function of amplitude and frequency of the poling field. Dynamic scaling of the switching loops was performed according to the power law <ASW>∝ Eαfβ. The lower negative value of β for Sm:PMN-PT suggests a shorter response time of crystallographic domains for it as compared to that for PMN-PT. The value of exponent α for PMN-PT was found to be higher in the low-field regime where 180° switching dominates the domain reorientation process. For Sm:PMN-PT, on the other hand, the value of α was found to be higher at high fields, which implies a superior ferroelastic domain reorientation. A similar power law scaling was also performed on the non-switching loops, which suggests a faster dynamic response of intrinsic polarization in Sm:PMN-PT as compared to that for PMN-PT. However, the intrinsic polarization in Sm:PMN-PT was found to be less responsive to the increasing field as compared to that for PMN-PT. We believe that the findings of this investigation would add another dimension to the understanding of the mechanism responsible for the high piezoelectric activity in samarium doped PMN-0.28PT crystal and polycrystalline ceramics.