Sodium Tracer Diffusion in an Alkaline-Earth Boroaluminosilicate Glass1
Lei Tian and Rüdiger Dieckmann
Department of Materials Science and
Engineering, Cornell University, Bard Hall, Ithaca, NY 14853-1501, U.S.A.
Abstract
Sodium tracer diffusion coefficients, D*Na, have been measured in an alkaline-earth boroaluminosilicate glass (Corning Code 1737) in the temperature range from 500 to 800 °C by using the radioactive isotope Na-22. It was found that the temperature dependence of D*Na could not be described by a simple Arrhenius-type function over the entire temperature range denoted above. A change in the activation energy occurs near the strain point (= 666 °C). Below 664 °C D*Na = 10(-2.21±0.07)·exp(-(129.9±1.2 kJ/mol)/R·T) cm2/s and above 664 oC D*Na = 10(-0.23±0.15)·exp(-(165.5±3.0 kJ/mol)/R·T) cm2/s.
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1 Corning Code 1737 glass
Experimental data for the diffusion of Na-22 in
the alkaline-earth boroaluminosilicate glass investigated (Corning Code 1737)
in air as a function of the temperature.
(Journal of Non-Crystalline Solids, 265 (1-2) [2000] 36-40)