Stability of the unswitched polarization state of ultrathin epitaxial Pb(Zr,Ti)O3 in large electric fields

作     者：Alexei Grigoriev Rebecca J. Sichel Ji Young Jo Samrat Choudhury Long-Qing Chen Ho Nyung Lee Eric C. Landahl Bernhard W. Adams Eric M. Dufresne Paul G. Evans 

作者机构：Department of Materials Science and Engineering and Materials Science Program University of Wisconsin Madison Wisconsin 53706 USA Department of Materials Science and Engineering Pennsylvania State University University Park Pennsylvania 16802 USA Materials Science and Technology Division Oak Ridge National Laboratory Oak Ridge Tennessee 37831 USA Advanced Photon Source Argonne National Laboratory Argonne Illinois 60439 USA 

出 版 物：《Physical Review B》 (物理学评论B辑：凝聚态物质与材料物理学)

年 卷 期：2009年第80卷第1期

页      面：014110-014110页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

基　　金：U.S. Department of Energy, Office of Basic Energy Sciences [DE-FG02-04ER46147] Basic Energy Sciences [DE-FG02-04ER46147] National Science Foundation [DMR-0705370] U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-AC0206CH11357] U.S. Department of Energy (DOE) [DE-FG02-04ER46147] Funding Source: U.S. Department of Energy (DOE) 

主　　题：dielectric polarisation electric domain walls epitaxial layers ferroelectric capacitors ferroelectric thin films lead compounds nucleation thin film capacitors X-ray diffraction 

摘      要：The initial stage of polarization switching in ferroelectric thin films depends on phenomena that occur at characteristic time scales of tens to hundreds of nanoseconds, including the nucleation polarization domains and the propagation of domain walls. These long intrinsic times allow short-duration electric fields with magnitudes far above the low-frequency coercive electric field to be applied across capacitor devices without inducing switching. Using time-resolved x-ray microdiffraction, we have found that a series of 50 ns duration electric field pulses switches the polarization of a 35-nm-thick ferroelectric Pb(Zr,Ti)O3 film only at electric fields greater than 1.5 MV/cm, a factor of three higher than the low-frequency coercive field. There is no switching in response to a large number of short pulses with amplitudes lower than 1.5 MV/cm, even when the total duration reaches several milliseconds. In comparison, a series of microsecond-duration pulses causes cumulative changes in the area of switched polarization and eventually switches the entire capacitor. The difference between long- and short-duration electric field pulses arises from effects linked to domain nucleation and charge transport in the ferroelectric film. A phase-field model shows that the shrinking of the switched domain in the interval between pulses is a less important effect. This opportunity to apply large fields for short times without inducing switching by domain-wall motion raises the possibility that future experiments could reach the intrinsic coercive field of ferroelectric layers and provides a way to study the properties of materials under high electric fields.