Temperature Dependence of the Entropy and the Heat Capacity Calculated from the Raman Frequency Shifts for Solid Benzene, Naphthalene and Anthracene

Yurtseven, Hasan Hamit
Ozdemir, Hilal
Temperature dependences of the free energy (F), entropy (S) and the heat capacity are calculated (P=0) for the organic compounds (solid benzene, naphthalene and anthracene) by using the quasiharmonic approximation. Contributions to those thermodynamic functions due to the Raman frequencies of lattice modes (solid benzene), librational modes (naphthalene), phonons and vibrons (anthracene) are taken into account in our calculations. We obtain that similar linear increase of F and nonlinear increase of S and, occur with the increasing temperature in benzene and naphthalene. This linear (F) and nonlinear (S, ) increase is rather different for anthracene as the molecular structure becomes complex (benzene-naphthalene-anthracene), as expected. Our calculations by the quasiharmonic approximation can be compared with the experiments for those organic compounds.


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Karacali, H; Yurtseven, Hasan Hamit (2006-01-11)
We calculate here the temperature dependence of the damping constant using the expressions derived from the Matsushita's theory and the temperature dependence of the order parameter from the molecular field theory for the tricritical (1.5 kbar) and second order (2.8 kbar) phase transitions in NH4Cl. Our calculations are performed for the nu(5) (174 cm(-1)) Raman mode of NH4Cl for the pressures studied. Predictions for the damping constant are in good agreement with our observed Raman bandwidths of this latt...
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Jalilian-Marian, J; Tekin, Bayram (1998-05-01)
We investigate the temperature dependence of eta and eta' masses due to scatterings from thermal pions in a heat bath using the nonlinear sigma model. We show that mass shifts of eta and eta' and the shift in the mixing angle are negligible.
Pressure dependence of the heat capacity near the melting point in benzene
Yurtseven, Hasan Hamit (2017-09-01)
The heat capacity C-p is calculated as a function of pressure at constant temperatures of 25, 40 and 51 degrees C for the solid and liquid phases of benzene near the melting point. For this calculation, the observed molar volume from the literature are used at various pressures for constant temperatures indicated through the thermodynamic relations in the solid and liquid phases of benzene near the melting point.
Temperature dependence of the isothermal bulk modulus of TiB2
Ozkan, H. (Elsevier BV, 2011-04-01)
The temperature dependencies of the isothermal bulk modulus of TiB2 above room temperature were calculated by using the equation for the Anderson- Gruneisen parameter (delta(T)) and its solution by Garai and Laugier (J. Appl. Phys. 101, 023514 (2007)). The present calculations utilize the relevant experimental data for the pressure derivative of the isothermal bulk modulus, K' as delta(T) in addition to the volume thermal expansion coefficients (alpha(V)). The temperature derivatives of the isothermal bulk ...
Temperature dependence of the Raman frequencies and bandwidths close to phase transitions in ammonium halides
Yurtseven, Hasan Hamit (2001-09-01)
In this study, we give the temperature dependence of our observed frequencies and bandwidths for the Raman optical modes in the ammonium halides close to the phase transitions of the first order (NH4 Br), tricritical (NH4Cl) and second order (NH4Cl). Using the predictions of an [sing pseudospin-phonon coupled model, which considers interactions between two spin and two phonons, our observed Raman data have been interpreted qualitatively. Our results show that an Ising model considered here can explain the o...
Citation Formats
H. H. Yurtseven and H. Ozdemir, “Temperature Dependence of the Entropy and the Heat Capacity Calculated from the Raman Frequency Shifts for Solid Benzene, Naphthalene and Anthracene,” INTERNATIONAL JOURNAL OF THERMODYNAMICS, vol. 25, no. 3, pp. 55–62, 2022, Accessed: 00, 2022. [Online]. Available: https://hdl.handle.net/11511/101067.