Calculation of the Damping Constant and the Relaxation Time for the Soft-Optic and Acoustic Mode in Hexagonal Barium Titanate

YURTSEVEN H. H., Kiraci A.

FERROELECTRICS, vol.437, pp.137-148, 2012 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 437
  • Publication Date: 2012
  • Doi Number: 10.1080/00150193.2012.742343
  • Journal Name: FERROELECTRICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.137-148
  • Keywords: Damping constant, relaxation time, hexagonal barium titanate, TEMPERATURE-DEPENDENCE, PHASE-TRANSITIONS, RAMAN-SCATTERING, NEUTRON-SCATTERING, PHONONS, SPECTROSCOPY, FREQUENCY, BATIO3
  • Middle East Technical University Affiliated: Yes

Abstract

The temperature dependence of the damping constant is calculated below the transition temperature (T-0 = 222K) in the ferroelectric phase of hexagonal barium titanate. The damping constant of the coupled soft-optic and acoustic mode which causes an intense central peak in the light scattering spectra, is calculated using the soft mode-hard mode coupling model and the energy fluctuation model for barium titanate.