Phase transitions in CuBiP2Se6 crystals |
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| Authors: | A Dziaugys J Banys J Macutkevic Yu Vysochanskii I Pritz M Gurzan |
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| Institution: | 1. Faculty of Physics , Vilnius University , Sauletekio 9 , LT-10222 Vilnius , Lithuania andrius.dziaugys@ff.vu.lt;3. Faculty of Physics , Vilnius University , Sauletekio 9 , LT-10222 Vilnius , Lithuania;4. Center for Physical Sciences and Technology , A. Gostauto 11, Vilnius , Lithuania;5. Institute of Solid State Physics and Chemistry of Uzhgorod University, Uzhgorod University , Uzhgorod , Ukraine |
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| Abstract: | Investigation results of dielectric (20?Hz–1?MHz) properties of layered CuBiP2Se6 crystals are presented. The temperature dependence of the static dielectric permittivity reveals the first-order “displacive” antiferroelectric phase transition at T c?=?136?K. In the paraelectric phase, at low frequencies, dielectric spectra are highly influenced by the high ionic conductivity with the activation energy of 2473?K (0.21?eV). In the antiferroelectric phase the electrical conductivity and its activation energy (531.1?K (0.045?eV)) are considerably smaller. At low temperatures, the temperature behaviour of the distribution of relaxation times reveals complex freezing phenomena. A part of long relaxation time distribution is strongly affected by external direct current (DC) electric field and it is obviously caused by antiferroelectric domain dynamics. |
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| Keywords: | dielectric spectroscopy electrical conductivity antiferroelectric phase transition dipolar glass |
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