This title appears in the Scientific Report : 2014 

Statistical electric field and switching time distributions in PZT 1Nb2Sr ceramics: Crystal- and microstructure effects
Zhukov, Sergey (Corresponding author)
Kungl, Hans / Genenko, Yuri A. / von Seggern, Heinz
Grundlagen der Elektrochemie; IEK-9
Journal of applied physics, 115 (2014) S. 014103
Melville, NY American Institute of Physics 2014
Journal Article
Fuel Cells
Renewable Energies
Please use the identifier: in citations.
Please use the identifier: in citations.
Dispersive polarization response of ferroelectric PZT ceramics is analyzed assuming theinhomogeneous field mechanism of polarization switching. In terms of this model, the localpolarization switching proceeds according to the Kolmogorov-Avrami-Ishibashi scenario with theswitching time determined by the local electric field. As a result, the total polarization reversal isdominated by the statistical distribution of the local field magnitudes. Microscopic parameters of thismodel (the high-field switching time and the activation field) as well as the statistical field andconsequent switching time distributions due to disorder at a mesoscopic scale can be directlydetermined from a set of experiments measuring the time dependence of the total polarizationswitching, when applying electric fields of different magnitudes. PZT 1Nb2Sr ceramics with Zr/Tiratios 51.5/48.5, 52.25/47.75, and 60/40 with four different grain sizes each were analyzed followingthis approach. Pronounced differences of field and switching time distributions were founddepending on the Zr/Ti ratios. Varying grain size also affects polarization reversal parameters, but inanother way. The field distributions remain almost constant with grain size whereas switching timesand activation field tend to decrease with increasing grain size. The quantitative changes of the latterparameters with grain size are very different depending on composition. The origin of the effects onthe field and switching time distributions are related to differences in structural and microstructuralcharacteristics of the materials and are discussed with respect to the hysteresis loops observed underbipolar electrical cycling.