Optical and electrical properties of SeO2 modified PbO-Bi2O3-B2O3 glasses

SeO2 doped high polarizable heavy metal oxides 10B(2)O(3)-40PbO-50Bi(2)O(3) glasses have been prepared by normal melt-quenching technique. The SeO2 modified glass structure, optical and electrical properties were studied using X-ray diffraction (XRD), ultraviolet-visible (UV-VIS), Fourier Transform Infrared Spectroscopy (FT-IR) and electrical measurement. Good vitrification was achieved for SeO2 up to 15%, exceed this value, Bi6SeO11 crystallines with size ranging from 20 nm to 50 nm would form in glass which was confirmed by XRD, scanning electron microscope (SEM), and energy dispersive X-ray spectrometry (EDS). Compared with 10B(2)O(3)-40PbO-50Bi(2)O(3) glass, the SeO2 modification decreased the band energy and accordingly red-shifted the cutoff edge greatly along with an increase of absorption in UV-VIS range. FT-IR spectra ascertained the co-existence of characteristic vibration bands of SeO42-, SeO32-, BiO6 and BiO6 frame units changed with SeO2 concentration. Such change in structure and optical property predominantly influenced the electrical conductivity, showing a progressive increase from 10(-6) to 10(-4) at 1-10(5) Hz and 473 K-573 K, due to the low gap energy, high polarizability, and non-bridging oxygen numbers induced by SeO32- ions in glass.