Electrical properties of Nb 2(1– y ) Ta 2y O 5 -based ceramics

We have studied the electrical properties of ceramic Nb 2(1– y ) Ta 2y O 5 samples, examined the dispersion of the real part of their dielectric permittivity ε′ at room temperature, and assessed their lattice dielectric permittivity ε′ ∞ The temperature dependences ε′( T ) have been obtained at different frequencies, and the dielectric loss tan δ has been evaluated as a function of measuring electric field frequency and temperature. The direct-current conductivity (σ dc ) of the solid solutions has been determined at room temperature. Using impedance spectroscopy data, we have obtained temperature dependences of σ dc for the Nb 2(1–y) Ta 2y O 5 ceramics and evaluated the activation enthalpy for charge transport in these materials in different temperature ranges.