Calculation of the specific heats for the II-III and II-IV phase transitions in NH4I

Yurtseven H. H., Kaya H.

CHINESE PHYSICS LETTERS, vol.20, no.1, pp.35-38, 2003 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 20 Issue: 1
  • Publication Date: 2003
  • Doi Number: 10.1088/0256-307x/20/1/311
  • Journal Name: CHINESE PHYSICS LETTERS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.35-38
  • Middle East Technical University Affiliated: Yes

Abstract

wThis study gives our calculation for the specific heats C-VI due to an Ising model using the observed C-P data for the II-III and II-IV phase transitions in NH4I. By fitting to the Cp data we determine the values of the critical exponent for the pressure of 0.14 GPa (II-III phase transition) and for the pressures of 0.75, 1.35 and 1.97GPa (II-IV phase transition) in NH4I. Our exponent values are close to the predicted values of the specific heat in a three-dimensional Ising model. Our calculated C-VI are in good agreement with the experimental Cp for NH4I in most cases.