MICROWAVE NONLINEAR DIELECTRIC MATERIALS

Abstract

Microwave nonlinearity and loss tangent data for alumina and stannate-doped (Ba0.5,Sr0.5)TiO3 (BST-50) near the Curie temperature are presented. A hot-pressed, annealed sample is included among the above materials. Similar data on alumina- and lanthana-doped (Ba0.7,Sr0.3)TiO3 (BST- 70), including a hot-pressed, annealed sample are presented. No unusual behavior was observed, and it is concluded that hot-pressing and annealing do little to improve the behavior of mixed titanate ceramics near the Curie temperature. A BaTiO3 ceramic doped with two mole percent of lanthana (La2O3) exhibited an extrapolated Curie temperature of +30C. Its nonlinearity and loss at the Curie peak were both comparable to those of BST-50 or BST-70. Lanthanum additions to SrTiO3 depressed the Curie temperature by an amount of 30-40C/mole percent lanthanum. The frequency dependence of the loss tangent of BST-50, BST- 70, and lanthana-doped BaTiO3 is seen to deviate strongly from linear dependence near the Curie temperature. The frequency ranges used were 2-4 Gc/ sec and 8-12 Gc/sec.

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Document Details

Document Type
Technical Report
Publication Date
Oct 14, 1964
Accession Number
AD0614274

Entities

People

  • A. Paladino
  • J. S. Waugh
  • Matthew W. Harris
  • P. B. Nutter

Organizations

  • RTX

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Air Force Facilities
  • Ceramic Materials
  • Crystal Growth
  • Crystals
  • Curie Temperature
  • Dielectrics
  • Electronics
  • Electronics Laboratories
  • Frequency
  • Materials
  • Microwave Frequency
  • Military Research
  • Phase Diagrams
  • Phase Transformations
  • Scattering
  • Single Crystals
  • Transition Temperature

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.