CRITICAL-VALUES FOR SPECIFIC-HEAT FROM RAMAN DATA


SHERMAN W., YURTSEVEN H.

JOURNAL OF MOLECULAR STRUCTURE, cilt.247, ss.61-71, 1991 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 247
  • Basım Tarihi: 1991
  • Doi Numarası: 10.1016/0022-2860(91)87063-n
  • Dergi Adı: JOURNAL OF MOLECULAR STRUCTURE
  • Sayfa Sayıları: ss.61-71

Özet

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.