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.