Dielectric properties of the ternary TeO2/Nb2O5/ZnO glasses

Glasses of the system TeO2/Nb2O5/ZnO containing different concentration of ZnO (ranging from 5 to 20 mol%) were prepared. The dielectric properties over wide ranges of frequencies and temperatures were investigated as a function of ZnO content by impedance spectroscopy measurements. The impedance spectra of the present glasses were modeled by appropriate equivalent circuit. The dielectric constant has a value of 66 for the 85TeO(2)/10Nb(2)O(5)/5ZnO glass which is three times larger than that of pure TeO2 glass and other binary, e.g. TeO2/ZnCl2, tellurite glassy systems. The results have been analyzed in light of varying NbO6 octahedra and NbO4 tetrahedra of niobium oxide as zinc oxide varies from 5 to 20 mol%. The relaxation properties of the investigated glasses are presented in the electric modulus formalism, where the relaxation time and the respective activation energy are determined. (c) 2005 Elsevier B.V. All rights reserved.