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Further Studies of the Crystallization of a Lithium Silicate Glass
Author(s) -
RINDOME GUY E.
Publication year - 1962
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.1151-2916.1962.tb11020.x
Subject(s) - crystallization , nucleation , silicate , lithium (medication) , materials science , silicate glass , platinum , phase (matter) , mineralogy , activation energy , chemical engineering , analytical chemistry (journal) , chemistry , composite material , chromatography , catalysis , organic chemistry , medicine , engineering , endocrinology
Rates of crystallization of Li 2 O · 2SiO 2 , from an Li 2 O · 4SiO 2 glass as a function of platinum concentration at 600° and 650° C were determined. At both temperatures a maximum rate was obtained in the region of 0.005% Pt. Calculations of the activation energies for the crystallization process showed that 0.005%, Pt lowered it to less than half its original value of 120 kcal per mole. Electron microscopy of this glass quenched from 1450OC revealed a granular structure 250 A in size which was believed to be due to lithium‐rich clusters in the glass, svpporting the concepts of other investigators. In glasses containing 0.025%, an additional phase identified as silica O was found. Explanations for the effectiveness of platinum as a nucleating agent in this glass are offered.