The dielectric properties and bipolar polarization-electric field (
P-
E) and strain-electric field (
S-
E) dynamic hysteresis of a relaxor [001]
c 0.73Pb(Mg
1/3Nb
2/3)O
3-0.27PbTiO
3 (PMN-0.27PT) single crystal were investigated to reveal more details of the temperature-induced phase transitions. Different linear scaling relations for ferroelectric hysteresis area <
A>, coercive field
Ec, saturation polarization
Ps and remnant polarization
Pr versus temperature
τ were measured in different temperature regions. For each measurement frequency
f, all hysteresis parameters were found to decrease linearly with temperature in the temperature range of the single rhombohedral (
R) phase or tetragonal (
T) phase, and the rate of decrease in the
T phase was observed to be much larger than the corresponding rate in the
R phase. In the temperature range near the
R-
T phase transition, the exponent
α in the power law <
A>∝
f α for the
R phase was found to be smaller than that for the
T phase, and the magnitude of
α depended strongly on temperature when the crystal was in the
R-
T coexisting phase state. Our experimental and theoretical results indicate that the difference in the activation energy and dipole moment in the
R and
T phases may lead to the observed discrepancy for the
P-E and
S-E hysteresis behaviour in different temperature regions.
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