Characterization of nickel based spinel ferrites with small substitution of praseodymium

The influence of pr3+ substitution on the structural,electrical and dielectric properties of ni-pr ferrites was studied in the ferrite series nipr2xfe2-2xo4 where x = 0 to 0.10 in steps of 0.02. this series was prepared by sol gel method. xrd analysis reveals single phase samples up to x = 0.04. at x ≥ 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. the electrical properties have been studied as a function of temperature. it is observed that dc electrical resistivity increases with increasing concentration of pr3+ ions. the activation energy was found to increase with increasing pr3+ ions. dielectric constant,dielectric loss factor and dielectric loss tangent were measured at room temperature in the frequency range from 100 hz to1mhz. a significant reduction in the values of dielectric constant and dielectric loss factor has been observed with the increase of pr3+ ions. the high dc resistivity and low dielectric losses are the desired characteristics of ni-pr ferrites used to prepare microwave devices.