Low Temperature Elastic and Dielectric Properties of Incommensurate Barium Sodium Niobate

Abstract

We have performed dielectric and Brillouin spectroscopic measurements on incommensurate (IC) Ba(2)NaNb(5)O(15) from ca. 15 K to room temperature and have related our measurements to earlier studies of birefringence and x-ray and neutron crystallography, with special emphasis upon the structural phase transition near 105 K and 40 K. The 105 K transition is from Ccm2(1) to a modulated structure, which appears to be a reentrant phase also found at atmospheric pressure from 565 K to 582 K. Such a reentrant IC/C/IC sequence is predicted in the phenomenological theory of Ishibashi. The lock-in phase below 40 K is tetragonal and probably of space group P4nc (structural refinements of preliminary neutron scattering data are in progress). (RRH)

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Document Details

Document Type
Technical Report
Publication Date
Dec 15, 1989
Accession Number
ADA216969

Entities

People

  • Elliot R. Bernstein
  • J. F. Scott
  • Robert D. Nowak
  • W. F. Oliver

Organizations

  • Colorado State University

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Sensors
  • Space
  • Weapons Technologies

DTIC Thesaurus Topics

  • Chemistry
  • Classification
  • Crystal Lattice Vibrations
  • Crystallography
  • Crystals
  • Data Acquisition
  • Diagrams
  • Dielectric Properties
  • Diffraction
  • Free Energy
  • Measurement
  • Military Research
  • Optical Properties
  • Phase Diagrams
  • Phase Transformations
  • Scattering
  • Transition Temperature

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Quantum Chemistry

Technology Areas

  • Space