Dielectric properties of manganese and cobalt doped lead iron tantalate ceramics

This paper reports the results of synthesis and sintering studies as well as dielectric properties of Pb(Fe1/2Ta1/2)O3 (PFT) relaxor ferroelectric ceramics. Influence of doping with MnO2 and Co3O4 (0.1-1 mol%) on resistivity and dielectric characteristics were investigated. The dielectric permittivity and dissipation factor of the ceramics were determined as a function of temperature in the range from −55 to 500 °C at frequencies 10 Hz to 1 MHz. DC resistivities of the samples were measured in the temperature range 20-500 °C. Two maxima in dielectric permittivity versus temperature curves were observed, dependent on frequency and the content of dopants. The investigated PFT ceramics were characterized by high dielectric permittivity of 3500-6700 at the transition temperature and 900-17,000 at the second maxima.