Effect of Na2SO4 substitution for Na2O on the structural and electricalproperties of a sodium borophosphate glass

International audienceThe effects of Na2SO4 substitution to Na2O on the structural and electrical properties of a sodium borophosphateglass system prepared by the melt/quenching method were investigated by means ofdifferent techniques. The amorphous nature of the glass was evidenced by X-ray diffraction (XRD).Differential scanning calorimetry (DSC) has showed a decrease of glass transition temperature (Tg) whiledensity measurements showed an increase of the molar volume Vm of the glass with the addition ofNa2SO4. Raman and infrared (FTIR) spectroscopies have revealed a significant structural change whichconfirms the behavior of Tg and Vm of the glass. Impedance measurements showed that the overallelectrical behavior originates from bulk contribution, whereas the frequency dependence of ac conductivitydoes not seem to follow the simple Jonscher's power law due to the electrode polarizationeffects. Moreover, the dc conductivity exhibits an Arrhenius-type behavior with temperature. Thedecrease of the activation energy and the increase of the electrical conductivity with the additionNa2SO4was discussed based on the results of the structural investigation of the glass