The influence of praseodymium (Pr) contents on the structural, electrical and dielectric properties of NixCO1-xPryFe2-yO4 ferrites was investigated. This series was prepared by sol-gel method. XRD analysis reveals single phase samples up to y ≤ 0.04. At y ≥ 0.06, a secondary phase of iron praseodymium oxide (PrFeO3) appears along with the spinel phase. The incorporation of Pr3+ for Fe3+ ions results in a slight increase of lattice constant due to larger ionic radius of the substituted ions. It was inferred that the substitution of praseodymium limits the grain growth. The DC electrical resistivity and activation energy are higher for the substituted samples. The dielectric constant, dielectric loss (tan δ) and AC-conductivity decreased on account of substitution. The decrease in dielectric constant is imputed to the reduction in the internal viscosity of the substituted samples. Ferrites have high dielectric constant and low tan δ, they may be attractive for application in switching and memory storage devices.

Muhammad Tahir Farid, Ishtiaq Ahmad, Ghulam Murtaza, Irshad Ali and Imtiaz Ahmad