Order-Disorder Transition in NCl. III. Specific Heat
- 1 August 1971
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 4 (3), 920-928
- https://doi.org/10.1103/physrevb.4.920
Abstract
The ac technique for measuring heat capacities is explained, and a model is presented to show the effects that the thermal properties of the heat link have on the observed temperature modulation. The ac technique is used to measure the heat capacity of ammonium chloride near the order-disorder transition at 242 °K. The measured heat capacities are analyzed using the theory presented in the first paper of this series. There is a strong sample dependence in the data that is not understood, but agreement with the theory is obtained for the sample with the sharpest transition. The critical exponents obtained from the fitting procedure are much closer to 1 than the theoretical values obtained from various model calculations.Keywords
This publication has 12 references indexed in Scilit:
- Order-Disorder Transition in NCl. II. Thermal ExpansionPhysical Review B, 1971
- Order-Disorder Transition in NCl. I. Phenomenological TheoryPhysical Review B, 1971
- Steady-State, ac-Temperature CalorimetryPhysical Review B, 1968
- AC Measurement of the Heat Capacity of Nickel Near its Critical PointPhysical Review Letters, 1967
- Order—Disorder Phenomena. III. Effect of Temperature and Pressure on the Elastic Constants of Ammonium ChlorideThe Journal of Chemical Physics, 1966
- Elastic Constants of Ammonium Chloride near the Lambda PointThe Journal of Chemical Physics, 1963
- Statistics of the simple cubic lattice. IIMathematical Proceedings of the Cambridge Philosophical Society, 1951
- 327. The effect of particle size and deuterium substitution on the λ-point in ammonium chlorideJournal of the Chemical Society, 1951
- The Variation of the Adiabatic and Isothermal Elastic Moduli and Coefficient of Thermal Expansion with Temperature through the-Point Transition in Ammonium ChloridePhysical Review B, 1940
- The P-V-T Relations of NCl and NBr, and in Particular the Effect of Pressure on the Volume AnomaliesPhysical Review B, 1931