Structural Inversion and Behavioural Changes as a Function of Composition in Sr-La-Al-B-Si Based Glasses

Abstract

A series of glass sealants for solid oxide fuel cell (SOFC) with compositions SrO (x wt %) La2O3 (15 wt %) Al2O3 (15 wt %) B2O3 (40-x wt %) SiO2 (30 wt %) [x = 10, 15, 20, 25 & 30] [SLABS] have been investigated by quantitative Fourier Transform Infrared Spectroscopy (FTIR). Structural findings from FTIR reveal that with increasing substitu-tion of B2O3 by SrO, even though the B2O3/SiO2 ratio decreases, however the Si-O- non-bridging bond content in the matrix is increasing and glass structure is getting more inverted. UV-Vis Diffused Reflectance Spectroscopy (UV-Vis-DRS) of the glass series shows that electrical band gap of glasses decreases in the series from 3.07eV to 2.97eV with increasing substitution from x = 10 to x = 30. Conductivities of the glass samples were measured by AC impedance spectroscopy and found to be increasing from 2.74 × 10-5 Scm-1 to 1.09 × 10-4 Scm-1 with increasing substitution from x =10 to x = 30.