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Growth of Single Crystals of Incongruently Melting Yttrium Iron Garnet by Flame Fusion Process
Author(s) -
RUDNESS R. G.,
KEBLER R. W.
Publication year - 1960
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.1151-2916.1960.tb09147.x
Subject(s) - yttrium , materials science , crystallite , single crystal , crystal growth , fusion , mullite , analytical chemistry (journal) , phase (matter) , crystallography , crystal (programming language) , mineralogy , metallurgy , chemistry , ceramic , oxide , linguistics , philosophy , organic chemistry , chromatography , computer science , programming language
Single crystals of yttrium iron garnet (Y 3 Fe 5 O 12 ) have been grown using the flame fusion process, even though the compound is reported to melt incongruently. The growth of these single crystals involves a mechanism different from that which has been proposed for the growth of single crystals of incongruently melting mullite. Crystal boules were grown at varying linear growth rates and analyzed with chemical, X‐ray, and metallographic techniques. With high linear growth rates, the samples are uniformly polycrystalline and three‐phase, containing Fe 2 O 3 , YFeO 3 , and Y 3 Fe 5 O 12 . When slow linear growth rates are used, single‐crystal Y 3 Fe 5 O 12 can be grown. The mechanism is as follows: At the beginning of growth the first phase to precipitate is YFeO 3 , and during this stage in growth the molten cap becomes enriched in Fe 2 O 3 , compared with the Y 3 Fe 5 O 12 composition. The liquid cap composition thus changes to the limit of the peritectic on the Fe 2 O 3 ‐rich side, and Y 3 Fe 6 O 12 then crystallizes from the bottom of the melt as Y 3 Fe 5 O 12 powder is added to the top of the molten cap. The central sections of these boules are single‐crystal yttrium iron garnet.