RESUMEN
Phosphate glasses containing 0.05-7.5g NiO/100 glass were prepared using sodium di-hydrogen phosphate. The prepared glasse were investigated using IR, a.c. conductivity, dielectric constant [epsilon'] and the dielectric loss [epsilon "]. IR spectra revealed that the Ni[2+] ions are located near P=O. Addition of Na[2]O causes a breakdown of the ring type with the formation of more non-bridging oxygens and depolymerization of the network. The conductivity of Ni-containing glasses is more than that of Ni-free phosphate glass, and attain maximum value for glass containing 0.25 g NiO per 100g glass. The relation between log sigma and reciprocal of the temperature suggests that, the mechanism predominating in the high temperature region is ionic in nature, while it is electronic in origin in the low temperature region. Introducing NiO extends electronic conduction through hopping mechanism to the high temperature region particularly at high frequency. The dielectric constant [epsilon'] and the dielectric loss [epsilon"] increase with increasing temperature, while a decrease in [epsilon'] with increasing frequency was observed