CRITICAL-VALUES FOR SPECIFIC-HEAT FROM RAMAN DATA


SHERMAN W., YURTSEVEN H.

JOURNAL OF MOLECULAR STRUCTURE, vol.247, pp.61-71, 1991 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 247
  • Publication Date: 1991
  • Doi Number: 10.1016/0022-2860(91)87063-n
  • Title of Journal : JOURNAL OF MOLECULAR STRUCTURE
  • Page Numbers: pp.61-71

Abstract

The use of Raman frequency shifts of non-soft modes to provide detailed predictions of the critical behaviour of specific heat up to within a fraction of a degree of a second order (or weakly first order) phase transition is illustrated. As an example, the lambda-transition of ammonium chloride under ambient pressure has been studied, and values of critical exponents of a- almost-equal-to 0.76 and a+ almost-equal-to 0.82 have been derived for C(p) from the Raman data. This approach is believed to be valid for a wide range of systems showing second-order or weakly first-order phase transitions and it is possible to use it for relatively inaccessible samples such as those within high pressure enclosures.