Correlation of structure and dielectric properties of silver selenomolybdate glasses

Abstract

Structure and dielectric properties of the glasses of compositions yAg2O-(1-y)(xSeO2-(1-x)MoO3) with varying modifier oxide and glass formers ratio have been reported in this paper. Fourier transform infrared (FTIR) spectroscopy has been employed to investigate the effect of SeO2 content on the glass network structure. The existence of different characteristic absorption bands corresponding to the vibration of SeO32− anions, isolated MoO6 units and crystalline molybdate octahedra, has been ascertained from FTIR spectra. It has been observed that the modification of the glass network structure occurs with change of SeO2 content, which reveals the dual role of SeO2 as a network modifier and a network former depending on composition. The dielectric constant as well as dielectric strength increases gradually with the increase of SeO2 content for low modifier oxide content (y), whereas they show a maximum for intermediate and highly modified glasses. The variation of the dielectric parameters correlates directly to the relative proportion of vibration mode of SeO32− ions, which is observed to vary in a similar fashion to dielectric parameters and is, thus in turn, related to the dual behavior of SeO2 as a modifier and a former depending on composition.