Obtaining and electrical properties of ceramics based on mixed niobium and tantalum pentoxide Nb2(1–y)Ta2yO5

详细

A method is developed for the preparation of mixed pentoxide Nb_2(1–y)Ta_2yO₅ by rapid coprecipitation of a mixture of hydroxides of niobium and tantalum from a solution of hydrofluoric acid by ammonia water, followed by purification and calcination of the precipitate. The proposed method allows obtaining a homogeneously mixed pentoxide of niobium and tantalum Nb_2(1–y)Ta_2yO₅, in contrast to the method of obtaining Nb_2(1–y)Ta_2yO₅ from a mechanical mixture of individual pentoxides of niobium and tantalum. The temperature dependences of the real part of the permittivity (ε′) of ceramic samples of Nb_2(1–y)Ta_2yO₅ at various frequencies were investigated and the magnitude of dielectric loss (tan(δ)) versus frequency measurement of the electric field and temperature was evaluated. On the basis of analysis of the data of impedance spectroscopy, the temperature dependence of the static conductivity σ_dс of the ceramic Nb_2(1–y)Ta_2yO₅ was determined. From the temperature dependence of σ_dс, the enthalpies of activation of charge transport for different temperature ranges were evaluated.