Calculation of the Raman frequencies using volume data close to the tricritical and second order phase transitions in NH4Cl

Date

2009-04-30

Author

Yurtseven, Hasan Hamit

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We calculate here the Raman frequencies of the v(5) TO(174 cm(-1)) and v(2) (1708 cm(-1)) modes as a function of temperature in the region of the tricritical (P = 1.6 kbar) and the second order (P = 2.8 kbar) phase transitions in NH4Cl. This calculation of the Raman frequencies is performed through the mode Gruneisen parameter by using the experimental length-change data obtained at zero pressure where the NH4Cl crystal exhibits a weakly first order phase transition (T-lambda = 242 K). The predicted Raman frequencies of the modes studied here, agree with our observed frequencies for the tricritical (T-c = 257 K) and second order (T-c = 268 K) transitions in NH4Cl.

Subject Keywords

Inorganic Chemistry, Organic Chemistry, Analytical Chemistry, Spectroscopy

URI

https://hdl.handle.net/11511/47872

Journal

JOURNAL OF MOLECULAR STRUCTURE

DOI

https://doi.org/10.1016/j.molstruc.2008.10.069

Collections

Department of Physics, Article

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Citation Formats

H. H. Yurtseven, “Calculation of the Raman frequencies using volume data close to the tricritical and second order phase transitions in NH4Cl,” JOURNAL OF MOLECULAR STRUCTURE, pp. 544–547, 2009, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/47872.