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Halogen Form in Calcium Borate Glasses Containing Iron
Author(s) -
Gohar I. A.,
Megahed A. A.,
Assem E. E.
Publication year - 1993
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.2170280215
Subject(s) - boron , halogen , halide , microstructure , phase (matter) , molar ratio , scanning electron microscope , ion , chemistry , inorganic chemistry , molar volume , calcium , mineralogy , nuclear chemistry , analytical chemistry (journal) , materials science , crystallography , organic chemistry , composite material , alkyl , physics , thermodynamics , catalysis
Some halogen‐doped calcium borate glasses containing iron have been prepared according to the precentage molar composition [(30‐X)CaO · x CaX 2 · 10 Fe 2 O 3 · 60 B 2 O 3 )] and annealed. Scanning electron micrographs of heat‐treated glasses show that the microstructure consists essentially of two phases. By introducing the halogen ion one of the primary phases (Ca‐rich borate) decreases in its volume and a new phase appears and exists as crystalline form. A secondary phase can also be produced which segregates in Ca‐rich borate as droplets. Magnetic susceptibility, molar volume, and infrared measurements revealed that at concentrations of CaX 2 < 10 mol% the halide ions may be introduced as modifiers and as network formers at CaX 2 concentrations > 10 mol%.