First Principles Calculations Using Linear Response Theory for Ferroelectrics

Abstract

First principles density functional methods using LAPW and LAPW linear response method were applied to study the incipient ferroelectric SrTiO3. Despite similarities to BaTiO3, SrTiO3 remains paraelectric down to zero temperature, transforming instead to an antiferrodistortive structure at 105 K. As a function of wavevector, the linear response calculations show structural instabilities along the R-M-R line in the Brillouin zone, consistent with this antiferrodistortive ground state. Although a ferroelectric type instability was also found near the zone center as in BaTiO3, the phase space of this instability is greatly reduced by comparison. Moreover, we find that the antiferrodistortive phase is stable, marginally, against ferroelectric structural distortions. In combination, these findings help explain the absence of a transition to a ferroelectric structure.

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Document Details

Document Type
Technical Report
Publication Date
Mar 17, 1998
Accession Number
ADA339560

Entities

People

  • Henry Krakauer

Organizations

  • College of William & Mary

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Brillouin Zones
  • Density Functional Theory
  • Dielectric Permittivity
  • Distortion
  • First Principles Calculations
  • High Temperature
  • Infrared Spectroscopy
  • Instability
  • Low Temperature
  • Molecular Dynamics
  • Neutron Scattering
  • Phase Transformations
  • Physical Properties
  • Transitions

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Plasma Physics / Magnetohydrodynamics

Technology Areas

  • Space