Accession Number : AD0277678

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

Corporate Author : PENNSALT CHEMICALS CORP PHILADELPHIA PA

Personal Author(s) : PHILLIPS,BERT ; WARSHAW,C.M. ; MOCKRIN,I.

Report Date : MAY 1962

Pagination or Media Count : 1

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)

Descriptors :   ALUMINUM COMPOUNDS, CHEMICAL EQUILIBRIUM, CRYSTAL STRUCTURE, DIELECTRIC PROPERTIES, MATERIALS, PHASE STUDIES, POTASSIUM COMPOUNDS, RUBIDIUM COMPOUNDS, STABILITY, SYNTHESIS

Distribution Statement : APPROVED FOR PUBLIC RELEASE