abstract
Relaxor ferroelectrics are a prototypical example of ferroic systems in which interplay between atomic disorder and order parameters gives rise to emergence of unusual properties, including non-exponential relaxations, memory effects, polarization rotations, and broad spectrum of bias-and temperature-induced phase transitions. Despite more than 40 years of extensive research following the original discovery of ferroelectric relaxors by the Smolensky group, the most basic aspect of these materials - the existence and nature of order parameter - has not been understood thoroughly. Using extensive imaging and spectroscopic studies by variable-temperature and time resolved piezoresponse force microscopy, we find that the observed mesoscopic behavior is consistent with the presence of two effective order parameters describing dynamic and static parts of polarization, respectively. The static component gives rise to rich spatially ordered systems on the similar to 100 nm length scales, and are only weakly responsive to electric field. The surface of relaxors undergoes a mesoscopic symmetry breaking leading to the freezing of polarization fluctuations and shift of corresponding transition temperature.
keywords
PIEZORESPONSE FORCE MICROSCOPY; REAL ORDER-PARAMETER; SINGLE-CRYSTALS; POLYCRYSTALLINE RELAXORS; ELECTRON-MICROSCOPY; GLASS-TRANSITION; THIN-FILMS; POLARIZATION; BEHAVIOR; PBMG1/3NB2/3O3
subject category
Chemistry; Science & Technology - Other Topics; Materials Science; Physics
authors
Kholkin, A; Morozovska, A; Kiselev, D; Bdikin, I; Rodriguez, B; Wu, PP; Bokov, A; Ye, ZG; Dkhil, B; Chen, LQ; Kosec, M; Kalinin, SV
our authors
Andrei Kholkin
Retired Researcheracknowledgements
We thank Prof. A. Tagantsev for valuable discussions and Dr. S. Drnovsek for the assistance with temperature measurements. The research was supported in part (S.V.K.) by the Division of Scientific User facilities, DOE BES (project CNMS2009-090). D.K. and A.K. are grateful to the Portuguese Foundation for Science and Technology (FCT) for the support within the PhD grant SFRH/BD/22391/2005 and project PTDC/FIS/81442/2006. A.B. and Z.-G. Y. acknowledge U.S. Office of Naval Research (N00014-06-0166) and the Natural Science & Engineering Research Council of Canada (NSERC) for the support.