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Crystalline Compounds and Glasses in the System B 2 O 3 ‐NaF‐NaBF 4
Author(s) -
MAYA LEON
Publication year - 1977
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.1151-2916.1977.tb15552.x
Subject(s) - boron , stoichiometry , raman spectroscopy , chemical composition , crystallography , oxide , boron oxide , chemistry , x ray crystallography , fluorine , phase (matter) , analytical chemistry (journal) , materials science , diffraction , physics , organic chemistry , chromatography , optics
The system B 2 O 3 ‐NaF‐NaBF, has been studied by subjecting selected compositions to thermal treatment in the range 400° to 600°C. Weight losses, chemical analyses, ir, Raman, and X‐ray diffraction techniques were used to define the composition of the crystalline phases and the structural units being formed in the system. The stoichiometry of the BF 3 evolved from NaBF 4 ‐B 2 O 3 mixtures indicated that a composition corresponding to Na 2 B 3 F 5 O 3 was formed in mixtures containing up to 33.3 mol% B 2 O 3 . At higher boron oxide concentrations, Na 2 B 3 F 5 O 3 was consumed, yielding 2NaF.3B 2 O 3 . The crystalline compounds Na 3 B 3 F 6 O 3 , 2NaF.3B 2 O 3 , and phase B (apparently NaF.B 2 O 3 ) were formed in the system. The compound Na 3 B 3 F 6 O 3 appeared as the stable oxygen‐containing species in NaBF 4 ‐NaF mixtures of low oxide content. The main fluorine‐containing structural units of the system are BF 4 , (–O) 3 BF, (–O) 2 BF 2 , (–O) 2 BF, whereas the main structure for binary NaF‐B 2 O 3 mixtures is (–O) 3 BF.