CALCULATION OF THE DAMPING CONSTANT AND ACTIVATION ENERGY FOR RAMAN MODES IN (NH4)(2)SO4

Date

2011-06-20

Author

Yurtseven, Hasan Hamit
Kiraci, A.

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The temperature dependence of the damping constant is calculated for various Raman modes in (NH4)(2)SO4 by the expressions derived from the soft mode hard mode coupling model and the energy fluctuation model. The expressions for the damping constant are fitted to the measured Raman bandwidths and then the activation energies are extracted, which are equal to similar to 0.2 eV for the Raman modes studied. The damping constant of a soft mode is also calculated and the activation energy (similar to 0.1 eV) is deduced in this crystal. Values of the activation energies obtained here, can be compared with the value of k(B)T(C) = 0.02 eV for (NH4)(2)SO4. This indicates that this ferroelectric material undergoes an order disorder transition. It is concluded that the observed behaviour of (NH4)(2)SO4 can be described reasonably by the soft mode hard mode coupling model considered here.

Subject Keywords

Statistical and Nonlinear Physics, Condensed Matter Physics

URI

https://hdl.handle.net/11511/44858

Journal

INTERNATIONAL JOURNAL OF MODERN PHYSICS B

DOI

https://doi.org/10.1142/s0217979211101582

Collections

Department of Physics, Article

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Citation Formats

H. H. Yurtseven and A. Kiraci, “CALCULATION OF THE DAMPING CONSTANT AND ACTIVATION ENERGY FOR RAMAN MODES IN (NH4)(2)SO4,” INTERNATIONAL JOURNAL OF MODERN PHYSICS B, pp. 2063–2080, 2011, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/44858.