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Kinetics of Crystallization of ZrF 4 ‐Ba 2 ‐LaF 3 Glass by Differential Scanning Calorimetry
Author(s) -
BANSAL NAROTTAM P.,
DOREMUS ROBERT H.,
BRUCE ALLAN J.,
MOYNIHAN C.T.
Publication year - 1983
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.1151-2916.1983.tb15704.x
Subject(s) - devitrification , differential scanning calorimetry , arrhenius equation , nucleation , isothermal process , thermodynamics , avrami equation , crystallization , kinetics , materials science , activation energy , analytical chemistry (journal) , chemistry , chromatography , physics , quantum mechanics
The kinetics of devitrification in ZrF 4 ‐BaF 2 ‐LaF 3 (62–33–5 mol % ) glass were studied by isothermal and nonisothermal methods using differential scanning calorimetry. The crystallization reaction followed the Avrami equation, x =1‐exp[—( kt) ], where x is the fraction crystallized after time t . The rate con stant k obeyed an Arrhenius equation, k(s −1 )=6.69 × 10 21 expThe value of the Avrami exponent, n , bas 3.2×0.2, indicating three‐dimensional crystal growth at a constant number of nucleation sites. Values of kinetics parame ters obtained from isothermal and nonisothermal techniques were in excellent agreement. The heat of crystallization measured from isothermal peaks was computed to be 38.5×3.5 J/g.