Macroscopic symmetry breaking and piezoelectricity in relaxor ferroelectric lead magnesium niobate

摘要

The piezoelectricity and electrostriction of a single crystal of the archetypical relaxor, lead magnesium niobate, (PbMg1/3Nb2/3O3, PMN), have been investigated by resonant piezoelectric spectroscopy (RPS) and resonant electrostriction spectroscopy (RES). RPS and RES measurements detect the piezoelectric effect and electrostriction up to similar to 730K and similar to 810 K, respectively, with the former being similar to 110 K above the Burns temperature TB. The observation of the piezoelectric effect above TB indicates that PNRs exist at such high temperatures and they lead to a non-zero time averaged polarization under the strain gradients induced by chemically ordered regions with Fm (3) over barm symmetry. Finally, coupled RES and RPS measurements may be a convenient approach to investigate mesoscopic and macroscopic polarity simultaneously, allowing to correlate the former with the latter. Published by AIP Publishing.