Specific heat calculated from the Raman frequency shifts close to the gimel-phase transition in NH4Br

Yurtseven H., Yanik A.

HIGH TEMPERATURES-HIGH PRESSURES, sa.3, ss.321-327, 2003 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Basım Tarihi: 2003
  • Doi Numarası: 10.1068/htjr070
  • Dergi Adı: HIGH TEMPERATURES-HIGH PRESSURES
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.321-327
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

We calculated the specific heat C-VI close to the lambda-phase transition in NH4Br on the basis of predictions of the Ising model. We have used our observed Raman frequencies of the nu(5) (134 cm(-1)) lattice mode to extract the critical exponent for the specific heat. The C-VI values calculated by us with this exponent value agree with the measured C-P data reported in the literature. This agreement is particularly good above T-lambda. This indicates that the observed behaviour of NH4Br can be satisfactorily explained close to the lambda-phase transition in this crystal.