Accession Number:

ADA289994

Title:

Fabrication and Characterization of Barium Strontium Titanate and Non-Ferroelectric Oxide Composites,

Descriptive Note:

Corporate Author:

ARMY RESEARCH LAB WATERTOWN MA MATERIALS DIRECTORATE

Personal Author(s):

• Ngo, E.
• Stowell, S.
• Sengupta, L. C.
• O'Day, M. E.
• Lancto, R.

Report Date:

1994-12-01

Pagination or Media Count:

13.0

Abstract:

Various composites of BSTO combined with other nonelectrically active oxide ceramics have been formulated. In general, the composites have adjustable electronic properties which can be tailored for use in various electronic devices. Two applications which are of interest in regard to the composites being discussed here, are phased array antennas and capacitor-varistor monolithic devices. For the phased array antennas, these properties include reduced dielectric constants, epsilon, where epsilon equals epsilon - iepsilon, and loss tangents, tan delta. The reduction of the dielectric constant and lowering of the loss tangents reduce the overall impedance mismatch and the insertion loss of the device. In addition, the overall tunability, change in the dielectric constant with applied voltage, is maintained at a sufficiently high level for all dielectric constants of interest. Another application for one of the composite materials is a combined capacitor-varistor device. In general, this would be used to protect against spurious voltage surges and voltage transients in electronic micro-circuits. The microstructures including grain size and phase analysis have been examined using SEM and X-ray diffraction. jg

Descriptors:

• *COMPOSITE MATERIALS
• *OXIDES
• *TITANATES
• *BARIUM COMPOUNDS
• *STRONTIUM COMPOUNDS
• TRANSIENTS
• MICROSTRUCTURE
• TUNABLE LASERS
• ELECTROMAGNETIC PROPERTIES
• X RAY DIFFRACTION
• ELECTRONIC EQUIPMENT
• VOLTAGE
• GRAIN SIZE
• REDUCTION
• ELECTRON MICROSCOPY
• CERAMIC MATERIALS
• DIELECTRIC PROPERTIES
• CONSTANTS
• LOSSES
• MONOLITHIC STRUCTURES(ELECTRONICS)
• INSERTION LOSS
• SURGES
• BARIUM TITANATES
• ANTENNA ARRAYS
• MICROCIRCUITS
• PHASED ARRAYS
• SPURIOUS EFFECTS
• CAPACITORS
• IMPEDANCE MATCHING
• VARISTORS

Subject Categories:

• Inorganic Chemistry
• Physical Chemistry
• Electrical and Electronic Equipment
• Ceramics, Refractories and Glass

Distribution Statement:

APPROVED FOR PUBLIC RELEASE