CHEMISTRY AND DIELECTRIC PROPERTIES OF FLUOALUMINATES. I. CHEMISTRY AND PHASE EQUILIBRIA

Abstract

Using differential thermal analysis, direct observational analysis and the quenching technique, the systems KF-AlF3, KAlF4-RbAlF4, and KAlF4RbAlF4-KBF4, were studied to establish the stability r lations of those tetrafluoaluminates which currently have the greatest pote tial as new dielectric ma erials. In the system KF-AlF3, two bi ry compounds are stable, namely K3AlF6 and KAlF4. The KAlF4 compound has a low-temperature inversion (between -23 and +50 C), below which it is rhombic and above which it is cubic. The stable structure exists up to the ''just congruent'' melting temperature of 546+-1 C. The system KAlF4-RbAlF4 forms a complete solid solution series with a maximum solidus-liquidus in erval of 10 C . The presence of as little as 5 mol-% RbAlF4 in the KAlF4 lattice gre tly affects the low-temperature inversion, reducing it below the temperature of liquid N. The solubility of KBF4 in KAlF4 and RbAlF4, which is approximately 10 and 18 mol-% respectively, suggests that a ternary solid solution of these tetrafluo lumi a s with the tetrafluoborate is possible. (Author)

Document Details

Document Type
Technical Report
Publication Date
May 01, 1962
Accession Number
AD0277678

Entities

People

  • Bert Phillips
  • C.m. Warshaw
  • I. Mockrin

Tags

DTIC Thesaurus Topics

  • Atmospheric Temperature
  • Chemistry
  • Dielectric Properties
  • Differential Thermal Analysis
  • Inversion
  • Low Temperature
  • Physical Chemistry
  • Solid Solutions
  • Temperature Inversion
  • Thermal Analysis

Readers

  • Materials Science and Engineering.
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