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Crystallization of Ca(PO 3 ) 2 Glass Below the Glass Transition Temperature
Author(s) -
ABE YOSHIHIRO,
ARAHORI TADAHISA,
NARUSE AKIRA
Publication year - 1976
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.1151-2916.1976.tb09414.x
Subject(s) - crystallization , glass transition , activation energy , crystal growth , crystal (programming language) , materials science , crystallography , surface tension , mineralogy , porous glass , analytical chemistry (journal) , chemical engineering , chemistry , thermodynamics , composite material , polymer , chromatography , programming language , physics , computer science , engineering , porosity
Block specimens of Ca(PO 3 ) 2 glass crystallize easily at temperatures considerably lower than the glass transition temperature, T g ; thin blown films of the glass do not exhibit this behavior. The crystals, which are β‐Ca(PO 3 ) 2 with a trace of the γ form, are identical to those formed above T g ; they exhibit “hemispherulitic” growth from the glass surface. The activation energy for crystal growth below T g is 30 kcal/mol, which indicates that the growth mechanism differs from that in blown film samples above T g (activation energy = 110 kcal/mol). A model for crystallization below T g is proposed; the phenomenon is explained in terms of induced tension in the molecular chains at the glass‐ crystal interface.