Ferroelectricity and Conduction in Ferroelectric Crystals.

Abstract

In the work to date on this contract, two important new advances have been made. Ferroelectric lithium thallium tartrate monohydrate has been shown to be of a new type, in which very strong piezoelectric coupling plays a major role in stabilizing the polar phase below 12 degrees K. The ferroelastic-ferroelectric-ferrimagnetic crystal nickel iodine boracite, which has cubic symmetry above 120 degrees K was shown to exhibit intrinsic optical anisotropy at room temperature. In continuing studies of the phenomenology and structure in the bismuth oxide family of ferroelectrics is studied and the possibility of intrinsic switching of P(s) in the c-direction at very low temperatures is suggested in Bi4Ti3O12. X-ray and neutron diffraction analysis has shown that the monoclinic shear in this crystal is not more than 40 seconds of arc, and a new structure based systematization of the other layer structures is proposed. Preliminary exploratory studies have shown some evidence of ferroelectricity in Beta-spodumen, which may be the first ferroelectric silicate structure. (Author)

Document Details

Document Type
Technical Report
Publication Date
Nov 30, 1970
Accession Number
AD0721479

Entities

People

  • Leslie E. Cross

Organizations

  • Pennsylvania State University

Tags

DTIC Thesaurus Topics

  • Bismuth Oxides
  • Crystals
  • Diffraction
  • Diffraction Analysis
  • Ferroelectric Crystals
  • Ferroelectricity
  • Low Temperature
  • Neutron Diffraction
  • X Rays

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Theoretical Analysis.