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Phase Relations in the System CaO‐Ta 2 O 5 ‐SiO 2
Author(s) -
REEVE D. A.,
BRIGHT NORMAN F. H.
Publication year - 1969
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1969.tb11968.x
Subject(s) - isostructural , ternary numeral system , phase (matter) , materials science , crystallization , quenching (fluorescence) , ternary operation , mineralogy , calcium , thermodynamics , crystallography , chemistry , metallurgy , crystal structure , optics , computer science , physics , organic chemistry , programming language , fluorescence
The system CaO‐Ta 2 O 3 ‐SiO 2 was studied using a combination of hot‐stage microscopy and the quenching technique. Primary crystallization fields were defined for the various calcium silicates, and for the calcium tantalates: CaO·2Ta 2 O 5 , CaO·Ta 2 O 5 , 2CaO·Ta 2 O 5 , and 4CaO·Ta 2 O 5 . A congruently melting ternary compound 10CaO·Ta 2 O 5 ·6SiO 2 , isostructural with the mineral niocalite, is the only ternary phase in the system. A large twoliquid region extends across the system from the CaO‐SiO 2 binary to within 1 wt% of the Ta 2 O 3 ‐SiO 2 binary but does not cut it, in marked contrast to the analogous CaO‐Nb 2 O 5 ‐SiO 2 system. Other somewhat unexpected differences were noted between these systems.