Landau mean-field model with the cubic term for the alpha-beta transition in quartz


Ates S., Yurtseven H.

BULLETIN OF MATERIALS SCIENCE, vol.43, no.1, 2020 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 43 Issue: 1
  • Publication Date: 2020
  • Doi Number: 10.1007/s12034-020-02127-1
  • Title of Journal : BULLETIN OF MATERIALS SCIENCE
  • Keywords: Landau model, alpha-beta transition, quartz, INCOMMENSURATE PHASE, TEMPERATURE-DEPENDENCE, MOLECULAR-DYNAMICS, ELASTIC-CONSTANTS, HEAT-CAPACITY, INSTABILITY, FREQUENCY, PHONON, RANGE

Abstract

Thermodynamic quantities are calculated as a function of temperature by using Landau mean-field model for the alpha-beta transition in quartz. By expanding the Gibbs free energy in terms of the order parameter (Q) with the cubic term (Q(3)), the temperature dependence of the relevant thermodynamic quantities are predicted using the heat capacity (C-P), which is fitted to the experimental data from the literature for the alpha-beta transition in quartz. Our results indicate that the Landau mean-field model is adequate to describe the first-order alpha-beta transition in quartz.