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 temperatureinduced
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 fi nd 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 ∼ 100 nm
length scales, and are only weakly responsive to electric fi eld. The surface of
relaxors undergoes a mesoscopic symmetry breaking leading to the freezing of
polarization fl uctuations and shift of corresponding transition temperature.
