Calculation of the specific heat close to the first-order and second-order phase transitions in ammonium halides

Date

2000-10-01

Author

Yurtseven, Hasan Hamit

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This study presents our calculation of the specific heat C-v1 under the prediction of an Ising model. For this calculation we used our observed Raman frequencies for the l'5LO (177 cm(-1)) mode of NH4Br, the v(5)TO (144 cm(-1)) and v(1)TA (93 cm(-1)) modes of NH4Cl close to the first-order phase transitions (P = 0). We also calculate the specific heat Cvi using our observed Raman frequencies for the v(1)TA (93 cm(-1)) mode of NH4Cl close to the second-order phase transition (P = 2.8 kbar) in this crystalline system.

Subject Keywords

Raman, Phase transitions, Ammonium halides

URI

https://hdl.handle.net/11511/56390

Journal

JOURNAL OF MOLECULAR STRUCTURE

DOI

https://doi.org/10.1016/s0022-2860(00)00570-6

Collections

Department of Physics, Article

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Calculation of the specific heat close to the multicritical and second order phase regions in ND4Cl Yurtseven, Hasan Hamit (Springer Science and Business Media LLC, 2007-12-01) We calculated the specific heat C-V of ND4Cl under the prediction of an Ising model presented here. Our calculated C (V) agrees with the experimental C (P) data for the multicritical (P = 0.1 MPa) and second order (P = 150 MPa) phase regions in this crystalline system. This agreement is particularly good above T (C) (congruent to 250 K)for the multicritical regime and below T (C) (congruent to 261 K) for the second order phase transition in ND4Cl. This shows that the observed behaviour of ND4Cl can be well ...
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Citation Formats

H. H. Yurtseven, “Calculation of the specific heat close to the first-order and second-order phase transitions in ammonium halides,” JOURNAL OF MOLECULAR STRUCTURE, pp. 267–279, 2000, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/56390.