Accession Number : AD0721479

Title :   Ferroelectricity and Conduction in Ferroelectric Crystals.

Descriptive Note : Interim rept. 1 Mar 69-31 Oct 70,

Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK MATERIALS RESEARCH LAB

Personal Author(s) : Cross,Leslie E.

Report Date : 30 NOV 1970

Pagination or Media Count : 219

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)

Descriptors :   (*FERROELECTRIC CRYSTALS, ELECTRICAL CONDUCTIVITY), (*TITANATES, FERROELECTRICITY), DIELECTRIC PROPERTIES, ELECTRICAL PROPERTIES, OPTICAL PROPERTIES, CRYSTAL GROWTH, PIEZOELECTRIC EFFECT, CRYOGENICS, BISMUTH COMPOUNDS, CRYSTAL STRUCTURE, SPODUMENE, LITHIUM COMPOUNDS, THALLIUM COMPOUNDS, TARTRATES, NICKEL COMPOUNDS, IODIDES, BORATES

Subject Categories : Electricity and Magnetism
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE