Effect of Pr3+ doping on magnetic and dielectric properties of Ni–Zn ferrites by “one-step synthesis”

Pr3+-doped Ni–Zn ferrites with a nominal composition of Ni0.5Zn0.5PrxFe2−xO4 (where x=0–0.08) were prepared by a one-step synthesis. The magnetic and dielectric properties of the as-prepared Ni–Zn ferrites were investigated. X-ray diffraction data indicated that, after doping, all samples consisted of the main spinel phase in combination of a small amount of a foreign PrFeO3 phase. The lattice constants of the ferrites initially increased after Pr3+ doping, but then became smaller with additional Pr3+ doping. The addition of Pr3+ resulted in a reduction of grain size and an increase of density and densification of the as-prepared samples. Magnetic measurement revealed that the saturation magnetization of the as-prepared ferrites, Ms, decreased, while the coercivity, Hc, increased with increasing substitution level, x, and the Curie temperature, Tc, kept a rather high value, fluctuating between 308 and 320 °C. Both the real and imaginary parts of permeability of the ferrites decreased slightly after Pr3+ doping. However, the natural resonance frequency shifted towards higher frequency from 13.07 to 36.17 MHz after the addition of Pr3+, driving the magnetic permeability to much higher frequency, reaching the highest value (36.17 MHz) when x=0.04. Introduction of Pr3+ ions into the Ni–Zn ferrite reduced the values of the dielectric loss tangent, especially in the frequency range of 1–400 MHz. However, the magnitude of dielectric loss of the samples doped with different amounts of Pr3+ raised little.

► One-step synthesis of Pr3+-doped Ni–Zn ferrites. ► Effect of Pr3+ doping on the magnetic and dielectric properties of Ni–Zn ferrites. ► Ferrites of low loss and high-frequency application.