TEMPERATURE DEPENDENT SPECTRUM OF AN ANTIFERRO-ELECTRIC LINEAR CHAIN MODEL

Abstract

Some general properties of the lattice vibrational spectra of antiferroelectric perovskite materials are proposed and illustrated with the use of a simple lattice model. It is shown that the existence of a low lying optical mode which is required to explain the dielectric properties in the cubic phase, suggests that an entire transverse optical branch should be low and temperature dependent. Each frequency of this branch can be characterized by an instability temperature. The mode with the highest instability temperature is the first to become unstable as the temperature is lowered. The calculated difference due to electrostatic interactions between the transition temperature and Curie temperature is shown to be of the same order as the observed difference for these materials. (Author)

Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1962
Accession Number
AD0276937

Entities

People

  • B.d. Silverman

Organizations

  • RTX

Tags

DTIC Thesaurus Topics

  • Crystal Lattice Vibrations
  • Crystal Lattices
  • Curie Temperature
  • Dielectric Properties
  • Diffraction
  • Frequency
  • Instability
  • Materials
  • Perovskites
  • Spectra
  • Transition Temperature
  • Transitions
  • Transverse
  • Vibrational Spectra
  • Wave Phenomena

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Molecular Photonics/Laser Physics
  • Thermal Physics or Thermal Science.