Accession Number:

ADA193512

Title:

Research on Crystal and Film Ferroelectric Materials for Optoelectronic Applications.

Descriptive Note:

Annual rept. 1 Mar 86-28 Feb 87,

Corporate Author:

ROCKWELL INTERNATIONAL THOUSAND OAKS CA SCIENCE CENTER

Personal Author(s):

• Neurgaonkar, R. R.

Report Date:

1988-03-01

Pagination or Media Count:

204.0

Abstract:

The millimeter wave dielectric behavior of several tungsten bronze ferroelectrics is presented, along with a theoretical evaluation of the origin of the dielectric losses which are shown to arise from polar microdomain fluctuations. Data is also presented for new, La-modified bronze SBN60 crystals which have very large dielectric constants at room temperature. A comprehensive thermodynamic phenomenology is presented for SBN60, showing a unique tetracritical phase transition behavior for this ferroelectric. This same phenomenology fails for bronze BSKNN crystals, however, indicating a heretofor unrecognized improper ferroelastic contribution to the dielectric properties. Keywords Electro-optic effect, Perovskite thin films.

Descriptors:

• *ELECTROOPTICS
• *FERROELECTRIC MATERIALS
• *THIN FILMS
• BRONZE
• CONSTANTS
• CRYSTALS
• DIELECTRIC PROPERTIES
• DIELECTRICS
• FILMS
• LOSSES
• MILLIMETER WAVES
• PEROVSKITES
• PHASE STUDIES
• PHASE TRANSFORMATIONS
• ROOM TEMPERATURE
• TEST AND EVALUATION
• THERMODYNAMICS
• TUNGSTEN
• METAL FILMS

Subject Categories:

• Electrooptical and Optoelectronic Devices

Distribution Statement:

APPROVED FOR PUBLIC RELEASE