Time evolution of polar regions in (Sr0.65Ba0.35)2NaNb5 O 15 single crystal |
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| Authors: | S Miga J Dec W Cao |
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| Institution: | 1. Institute of Physics, University of Silesia, ul. Uniwersytecka 4 , 40-007 Katowice, Poland miga@us.edu.pl;3. Institute of Physics, University of Silesia, ul. Uniwersytecka 4 , 40-007 Katowice, Poland;4. Department of Mathematics and Materials Research Institute , The Pennsylvania State University , PA 16802, USA |
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| Abstract: | The linear, second-order and third-order dielectric susceptibilities χ1, χ2, χ3 of a (Sr0.65Ba0.35)2NaNb5O15 (SBNN) single crystal have been measured. Strong relaxation was found in all investigated dielectric susceptibilities near the phase transition. The time dependence of linear and third-order dielectric susceptibility can be explained as the effect of polar nano-clusters evolution. Near the phase transition, the net polarization of the crystal, monitored by second-order dielectric susceptibility, changes both its value and orientation. Measurements of the pyroelectric effect indicate that the non-zero net polarization in SBNN crystals appears spontaneously. In addition, the ferroelectric phase transition in SBNN showed many features of a first-order phase transition. |
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| Keywords: | Relaxor Phase transition Linear and nonlinear dielectric susceptibilities Aging Polar nano-regions |
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