Pippard relation modified for the rotatory lattice mode in ammonia solid II


Yurtseven H.

HIGH TEMPERATURE MATERIALS AND PROCESSES, vol.24, no.5, pp.315-322, 2005 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 24 Issue: 5
  • Publication Date: 2005
  • Doi Number: 10.1515/htmp.2005.24.5.315
  • Title of Journal : HIGH TEMPERATURE MATERIALS AND PROCESSES
  • Page Numbers: pp.315-322

Abstract

In this study we obtain a linear variation of the specific heat Cp with the Raman frequency shifts 1/v (partial derivative v/partial derivative T)p for the rotatory lattice (librational) mode in the ammonia solid II near the melting point. From this linearity, we deduce values of the slope dP(m)/dT for the pressures of 3.65, 5.02 and 6.57 kbars in the ammonia solid II. Our calculated value of dP(m)/dT for the pressure of 3.65 kbar, is in good agreement with the experimentally measured value in the P-T phase diagram of this crystalline system. This indicates that the first Pippard relation modified for the rotatory lattice mode in the ammonia solid II, is satisfactory near the melting point.