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Calculation of the Spontaneous Polarization and the Dielectric Constant as a Function of Temperature for KH2PO4
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Date
2012-01-01
Author
Yurtseven, Hasan Hamit
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The temperature dependence of the spontaneous polarization P is calculated in the ferroelectric phase (T < T-C) of KH2PO4 (KDP) at atmospheric pressure (T-C = 122 K). Also, the dielectric constant e is calculated at various temperatures in the paraelectric phase (T > T-C) of KDP at atmospheric pressure. For this calculation of P and epsilon, by fitting the observed Raman frequencies of the soft mode, the microscopic parameters of the pure tunnelling model are obtained. In this model, the proton-lattice interaction is not considered and the collective proton mode is identified with the soft-mode response of the system. Our calculations show that the spontaneous polarization decreases continuously in the ferroelectric phase as approaching the transition temperature T-C. Also, the dielectric constant decreases with increasing temperature and it diverges in the vicinity of the transition temperature (T-C = 122 K) for KDP according to the Curie-Weiss law.
Subject Keywords
Ferroelectric mode
,
damping constant
,
phase-transition
,
raman frequency
,
soft mode
,
pressure
URI
https://hdl.handle.net/11511/44128
Journal
ADVANCES IN CONDENSED MATTER PHYSICS
DOI
https://doi.org/10.1155/2012/259712
Collections
Department of Physics, Article
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H. H. Yurtseven, “Calculation of the Spontaneous Polarization and the Dielectric Constant as a Function of Temperature for KH2PO4,”
ADVANCES IN CONDENSED MATTER PHYSICS
, pp. 0–0, 2012, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/44128.