Calculation of the Spontaneous Polarization and the Dielectric Constant as a Function of Temperature for KH2PO4

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2012-01-01

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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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Citation Formats

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.