Analysis of the Raman frequencies close to the lambda-phase transition in NH4Cl

Yurtseven H., Tuzer T. U.

JOURNAL OF MOLECULAR STRUCTURE, vol.834, pp.426-429, 2007 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 834
  • Publication Date: 2007
  • Doi Number: 10.1016/j.molstruc.2006.10.062
  • Journal Name: JOURNAL OF MOLECULAR STRUCTURE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.426-429
  • Middle East Technical University Affiliated: Yes

Abstract

This study gives our analysis of the Raman frequencies for the lattice modes of v(5)TO(174 cm(-1)), v(5)TO(144 cm(-1)) and v(7)TA(93 cm(-1)), and an internal mode of v(2)(1708 cm(-1)) as functions of temperature in NH4Cl close to its lambda-phase transition (T-lambda = 241.2 K, P = 0). This analysis is performed using a power-law formula with the critical exponent beta for the order parameter according to the soft mode-hard mode coupling model.