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Phase Equilibria in the TiO 2 ‐Rich Region of the System BaO‐TiO 2
Author(s) -
O'BRYAN H. M.,
THOMSON J.
Publication year - 1974
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.1151-2916.1974.tb10801.x
Subject(s) - eutectic system , phase diagram , solidus , phase (matter) , materials science , mineralogy , differential thermal analysis , crystallography , titanate , analytical chemistry (journal) , metallurgy , microstructure , chemistry , diffraction , ceramic , physics , organic chemistry , alloy , optics , chromatography
Phase relations in the system BaO‐TiO 2 from 67 to 100 mol% TiO 2 were investigated at 1200° to 1450°C in O 2 . Data were obtained by microstructural, X‐ray, and thermal analyses. The existence of the stable compounds Ba 6 Ti 17 O 40 , Ba 4 Ti 13 O 30 , BaTi 4 O 9 , and Ba 2 Ti 9 O 20 was confirmed. The compound BaTi 2 O 5 is unstable and either forms as a reaction intermediate below the solidus or crystallizes from the melt. The compounds Ba 6 Ti 17 O 40 and Ba 4 Ti 13 O 30 decompose in peritectic reactions, and BaTiO 3 and Ba 6 Ti 17 O 40 react to form a eutectic. Special conditions are required for the formation of Ba 2 Ti 9 O 20 , which decomposes in a peritectoid reaction at 1420°C. The new phase diagram is presented.