Structural, thermal and crystallization kinetics of ZnO-BaO-SiO2-B2O3-Mn2O3 based glass sealants for solid oxide fuel cells

Glass compositions in the system 40SiO(2)-30BaO-20ZnO-(x)Mn2O3-(10 - x)B2O3 glasses have been synthesized and the thermal, structural and crystallization kinetic properties characterized. The lower concentration of Mn2O3 in place of B2O3 acts as a network former and suppressed the tendency of phase separation in glasses. On the other hand, concentration of Mn2O3 > 7.5 mol% induce phase separation in the glass matrix. The highest activation energy for crystallization is observed in the composition without B2O3 (INM4) (355 kJ/mol). The values of thermal expansion coefficient (TEC) and viscosity of this glass is 8 x 10(-6) K-1 and 10(4.2)dPa s (850 degrees C), respectively. After long heat treatment (800 degrees C for 100 h), thermodynamically stable hexacelsian and monoclinic phases are formed. These phases are not detrimental to SOFC application. (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.