Impedance Studies of Phosphate-iron Glasses Containing Niobium and Titanium

The ac and dc conductivity in phosphate-iron-niobate glasses with addition of titanium oxide was investigated as a function of temperature and frequency with the use of impedance spectroscopy. The topography and microstructure of glasses were investigated by the means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and confocal microscopy methods. The obtained results show that all samples are amorphous but they contain granular structures. The influence of titania on the properties of obtained glasses is discussed. The activation energy of dc conduction process is determined. The experimental results are discussed on the basis of Jonscher law and conductivity models collected by Elliot.