Investigation of crystallization kinetic of SrO-La(2)O(3)-Al(2)O(3)-B(2)O(3)-SiO(2) glass and its suitability for SOFC sealant

Strontium-lanthanum-aluminoborosilicate (SrO-La(2)O(3)-Al(2)O(3)-B(2)O(3)-SiO(2)) (SLABS) glass was prepared for sealant material in planar Solid Oxide Fuel Cells (pSOFC). Differential Thermal Analysis of the glass showed the formation of two crystalline phases, first one 807 degrees C and the second phase at 1021 degrees C. Crystallization kinetic of the first crystalline phase was investigated by differential thermal analysis (DTA) and using the JMA-kinetic model. The activation energy for crystallization was calculated to be 114.04 kJ/mol with frequency factor 5.9 x 10(3). Coefficient of Thermal Expansion (CTE) of the glass was measured to be 9.72 x 10(-6)/degrees C. Optical band gap of the glass was measured to be 3.07 eV. Conductivity measured by Impedance spectroscopy found to be 5.68 x 10(-7) S cm(-1) at 600 degrees C and it increased with temperature to 2.68 x 10(-6) S cm(-1) at 800 degrees C. Activation energy for electrical conduction was measured to be 66.12 kJ/mol. Wetting behavior of the glass on a ferritic steel substrate was investigated under hot stage microscopy. It showed initial deformation temperature (IDT) 754 degrees C, softening temperature (ST) 840 degrees C, hemispherical temperature (HT) 1108 degrees C and flow temperature (FT) 1279 degrees C. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.