High permittivity thick film based on Pb(Fe1/2Ta1/2)O3 - Pb(Fe1/2Nb1/2)O3 - PbTiO3 solid solutions

Ferroelectric pastes based on Pb(Fe1/2Ta1/2)O3 - Pb(Fe1/2Nb1/2)O3 - PbTiO3 solid solutions were prepared and applied for manufacturing thick film capacitors. Capacitance and dissipation factor of the dielectric layers were measured in the temperature range from -55 to 480oC at frequencies 10 Hz - 1 MHz. Temperature dependence of resistivity of thick films was determined in the range 20-500oC. Two broad maxima in dielectric permittivity versus temperature plots were observed at a given frequency, corresponding to the ferroelectric-paraelectric transition and to dielectric relaxation. The layers showed dense microstructure, high maximum values of dielectric permittivity (1700-4000 at Curie temperature) and low temperature coefficients of capacitance in the temperature range from -55 to 125oC. (author)