Phase Separation and Electrical Properties of Manganese Borosilicate Glasses

The structure and electrical properties of manganese borosilicate glasses of a composition of xMnO-(0.8-x)SiO2-(0.2)B2O3 (x=0.4, 0.5 and 0.6 in mol) were investigated by impedance spectroscopy, SEM, XRD and confocal microscopy methods. The influence of composition on the glass structure and electrical properties was discussed. A separation of two amorphous phases was observed and it was concluded that one phase is SiO2-rich and the other is MnO-rich. It was found that the direct current conductivity and the activation energy of conductivity decreases with an increase in the manganese oxide content. The proposed mechanism of the conductivity is overlapping large polaron hopping.