Abstract
The fatigue effect has been studied experimentally in stoichiometric lithium tantalate single crystals produced by vapor transport equilibration with solid-state electrodes. It was shown that fatigue effect is due to increase of the frozen domain area composed of domains with charged domain walls (CDW). The formation of CDW: 1) hampers the domain kinetics by wall motion, 2) makes partial switching easier resulting in increase of the dielectric response, 3) decreases the threshold fields as the nucleation starts at the boundaries of frozen areas. The dependence of switched charge fraction on the cycle number has been analyzed by modified Kolmogorov-Avrami formula.
Acknowledgments
The research was made possible in part by RFBR (Grants 10-02-96042-r-Ural-а, 10-02-00627-а, 11-02-91066-CNRS-а), by Ministry of Education and Science (Contract 16.552 11 7020).