Effect of Transition-Metal Ions (Ni2+, Cu2+ and Co2+) on the Electric and Dielectric Properties of Zinc Sodium Phosphate

Resumo

In this work, the influence of transition-metal ions doping on the zinc phosphate glass has been investigated. To do so, a series of glass doped with Ni²⁺, Cu²⁺and Co²⁺ at different ratio (1, 2 and 5 mol %) was synthesized. The Fourier transform infrared spectra was used to elucidate the bonding system of the constituent atoms. The dielectric and conductivity properties were studied by impedance spectroscopy over a frequency range from 10^–2 Hz to 1 MHz at different temperatures. The changes in the conductivity and activation energy dependon the chemical composition and indicate a changeover of the predominant conduction mechanism from ionic to polaronic. The results have shown a lower electrical conductivity for glass containing CuO. This is related to the lower depolymerization degree of the glass network by Cu²⁺ ions. The dielectric constant and dielectric loss increased with the temperature and decreased with the frequency for all glasses studied. The variation of the value s factor for all glass samples as the function of temperature agrees with the correlated barrier-hopping (CBH) model.