Change in dielectric properties induced by iron addition to gallium–bismuthate glasses

Glasses of various compositions belonging to the xFe2O3 · (80 − x)Bi2O3 · 20Ga2O3 system were prepared via a melt quenching technique. The dielectric properties of samples, dielectric constant εr and loss tan δ, were investigated as a function of iron content (0 ⩽ x ⩽ 20 mol%), temperature (from room temperature up to 200 °C) and frequency (1, 10 and 100 kHz). The temperature at which the dispersion of the dielectric constant starts to be observed was determined as function on iron content.