Dielectric behavior of nanocrystalline Cu-Fe ferrites synthesized by plasma arc discharge process

Abstract

In this study, nanocrystalline Cu–Fe ferrite powders with the chemical composition of CuxFe1-xFe2O4 (where 0 ≤ x ≤ 0.5) were synthesized via the plasma arc discharge process. Regarding the phase analysis, a spinel structure of the nanocrystalline Cu–Fe ferrite phase has been developed successfully in all synthesized compositions. Dielectric properties were measured in the 100 Hz to 10 MHz range using an LCR meter. Results show that the substitution of Cu for Fe ions leads to a substantial increase in the dielectric constant due to the migration of some Fe3+ ions from tetrahedral to octahedral sites and the formation of Cu+/Cu2+ ion pairs in the octahedral sites contributing to the hopping process. The results also indicate that the low-frequency dielectric constant is influenced by grain boundary capacitance while grain capacitance plays a major contribution to the dielectric constant in the high-frequency region.