ORDER-ORDER PHASE TRANSISTIONS IN FERROELECTRICS.

Abstract

The current theories of ferroelectric phase transitions are reviewed with particular reference to the form of the excitations. Since a well defined order exists both above and below Tc one expects these to have meaning in both phases. The unharmonic phonon model of pevovskites and the pseudo-spin model of KH2PO4 are considered in detail, and the similarities remarked on. The main problems centre on the damping of the excitations particularly close to Tc in the initial region. Neither theory nor experiment gives a refined view of this question. (Author)

Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1968
Accession Number
AD0832976

Entities

People

  • J. A. Krumhansl
  • Robert J. Elliott

Organizations

  • University of Oxford

Tags

DTIC Thesaurus Topics

  • Excitation
  • Phase Transformations
  • Transitions

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Quantum spin resonance or Electron Paramagnetic Resonance spectroscopy.
  • Theoretical Analysis.