Electrical conductivity and dielectric properties of rare earth ions (Ce3+, Pr3+ and Eu3+) doped in zinc sodium phosphate glass

Abstract

The zinc phosphate glass (composition Na2–3xMxZnP2O7) doped with different rare earth ions (x = 1 mol% where M = Ce, Pr and Eu), were synthesized by the classical melting and quenching processes. Electrical and dielectric properties including dielectric constantε′(ω), loss tangenttanδ, as well as electric conductivityσac, have been investigated over a wide continuous frequency range from 10−2 Hz to 106 Hz over a temperature range 283 K to 473 K using complex impedance spectroscopy (CIS). The results revealed that the conductivity decreases and activation energy increases with the ionic radii of cations (from Eu3+to Ce3+) likely due to the size mismatch. This behaviour could be attributed to the depolymerization of the glass network by Eu3+. This induces the decrease of the electrostatic binding and strains energies facilitating the passage of sodium ions. The average value of the power law exponent s is interpreted by the correlated barrier hopping (CBH) model.