TY - JOUR
T1 - Sodium tracer diffusion in sodium boroaluminosilicate glasses
AU - Wu, Xinwei
AU - Moskowitz, Jeremy D.
AU - Mauro, John C.
AU - Potuzak, Marcel
AU - Zheng, Qiuju
AU - Dieckmann, Rüdiger
N1 - Funding Information:
This work was supported by the National Science Foundation under award number DMR-0710564 . The work made use of the Cornell Center for Materials Research Facilities supported by the National Science Foundation under award number DMR-1120296 . The authors thank all undergraduate researchers at Cornell who helped in the experimental work.
Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012/7/1
Y1 - 2012/7/1
N2 - Sodium tracer diffusion coefficients, D* Na, have been measured using the radioactive isotope Na-22 in sodium boroaluminosilicate (NBAS) glasses containing either a small amount of As 2O 3 or Fe 2O 3. The chemical compositions of the first type of glasses are given by the formula [(Na 2O) 0.71(Fe 2O 3) 0.05(B 2O 3) 0.24] 0.2[(SiO 2) x(Al 2O 3) 1 - x] 0.8 and those of the second type of glasses correspond to the formula [(Na 2O) 0.73(B 2O 3) 0.24(As 2O 3) 0.03] 0.18[(SiO 2) x(Al 2O 3) 1 - x] 0.82. Tracer diffusion measurements were performed at different temperatures between 198 and 350 °C. Pre-annealing of the glass samples at their glass transition temperatures in common air was found to lead to changes in the values of sodium tracer diffusion coefficients. For the NBAS glasses containing Fe 2O 3, after pre-annealing for 5 h, the activation enthalpy derived for the sodium tracer diffusion increases almost linearly from 57.5 to 71.3 kJ/mol with a decrease in the alumina content while the pre-exponential factor of the sodium tracer diffusion coefficient increases from 2.1·10 - 4 to 5.3·10 - 4 cm 2/s. For the iron-free NBAS glasses pre-annealed for 5 h, the activation enthalpy varies between 63.9 and 71.4 kJ/mol while the pre-exponential factor varies between 1.5·10 - 4 and 1.2·10 - 3 cm 2/s. In addition, it was observed that the considered glasses take up water when annealed at 300°C in wet air with P H 2O = 474 mbar.
AB - Sodium tracer diffusion coefficients, D* Na, have been measured using the radioactive isotope Na-22 in sodium boroaluminosilicate (NBAS) glasses containing either a small amount of As 2O 3 or Fe 2O 3. The chemical compositions of the first type of glasses are given by the formula [(Na 2O) 0.71(Fe 2O 3) 0.05(B 2O 3) 0.24] 0.2[(SiO 2) x(Al 2O 3) 1 - x] 0.8 and those of the second type of glasses correspond to the formula [(Na 2O) 0.73(B 2O 3) 0.24(As 2O 3) 0.03] 0.18[(SiO 2) x(Al 2O 3) 1 - x] 0.82. Tracer diffusion measurements were performed at different temperatures between 198 and 350 °C. Pre-annealing of the glass samples at their glass transition temperatures in common air was found to lead to changes in the values of sodium tracer diffusion coefficients. For the NBAS glasses containing Fe 2O 3, after pre-annealing for 5 h, the activation enthalpy derived for the sodium tracer diffusion increases almost linearly from 57.5 to 71.3 kJ/mol with a decrease in the alumina content while the pre-exponential factor of the sodium tracer diffusion coefficient increases from 2.1·10 - 4 to 5.3·10 - 4 cm 2/s. For the iron-free NBAS glasses pre-annealed for 5 h, the activation enthalpy varies between 63.9 and 71.4 kJ/mol while the pre-exponential factor varies between 1.5·10 - 4 and 1.2·10 - 3 cm 2/s. In addition, it was observed that the considered glasses take up water when annealed at 300°C in wet air with P H 2O = 474 mbar.
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U2 - 10.1016/j.jnoncrysol.2012.03.004
DO - 10.1016/j.jnoncrysol.2012.03.004
M3 - Article
AN - SCOPUS:84861850550
VL - 358
SP - 1430
EP - 1437
JO - Journal of Non-Crystalline Solids
JF - Journal of Non-Crystalline Solids
SN - 0022-3093
IS - 12-13
ER -