MIXED AC CONDUCTIVITY STUDIES IN ALKALI AND TRANSITION METAL IONS DOPED BORATE GLASSES

In the present study, B2O3 glasses doped with Na2O and Fe2O3 was prepared via melt quenching method. The amorphous nature of the samples has been confirmed by the XRD studies. The polaronic conduction for the wide range of temperature and frequency were studied. As temperature increases the dielectric properties found to be enhanced and with increment in frequency they found to be decreased. The high temperature ac conductivity data has been analyzed by Motts small polaron hopping model (SPH). Activation energy passed through maximum and conductivity passed through minimum at 0.20 concentrations of sodium oxide which attributes that the switch over of conduction process, taking place at 0.20 molar fraction of alkali ions from primarily polaronic to ionic in the present series of glasses.