Electronic and ionic relaxations in strontium–borate glass and glass-ceramics containing bismuth and vanadium oxides

• SBO glasses with bismuth and vanadium oxides consist of two amorphous phases.
• No para-ferroelectric phase transition is observed in tested materials.
• Conduction mechanism at low temperatures is mixed electronic and ionic.
• At high-temperature region, the dominating conduction mechanism is ionic.

The topography, microstructure, and electrical properties of strontium–borate glass and SBO glass containing bismuth and vanadium oxides, were studied. The structure was measured using X-ray diffraction (XRD), energy dispersive X-ray spectrometer (EDS), and scanning electron microscope (SEM) methods. The A.C. complex conductivity was investigated as a function of temperature and frequency. The influence of the quantity of bismuth and vanadium oxides present, on glasses microstructure and electrical properties, was discussed.In order to obtain glass-ceramics, the glasses were subjected to crystallization at temperatures close to the exothermic processes indicated by the differential scanning calorimetry (DSC) measurements. X-ray diffraction (XRD) measurements were carried out to determine the presence of bismuth vanadate (Bi2VO5.5) crystalline phase in heat-treated samples. After heat treatment, there were still some traces of the glassy phase within the samples. The effect of the crystallization process on the microstructure, topography, and dielectric behavior of the material was analyzed. The A.C. dielectric permittivity, conductivity, and impedance were discussed at specific temperature and frequency region; in addition, conduction mechanisms were proposed.