Investigation of structural and magnetic properties of Zr-Co doped nickel ferrite nanomaterials

Abstract Nano-sized Zr-Co doped nickel ferrites with nominal composition, NiZr x Co x Fe 2-2x O 4 ( x =0.0, 0.2, 0.4, 0.6, 0.8) were synthesized using the micro-emulsion route. The structural elucidation of the synthesized materials was carried out by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The XRD analysis confirmed face centered cubic (FCC) structure of all compositions of NiZr x Co x Fe 2-2x O 4 nanocrystallites. Crystallite size was calculated by Scherrer's formula found in the range 10–15 nm. The variation in lattice parameter as determined by XRD data agreed with size variation of host (Fe 3+ ) and guest (Zr 4+ and Co 2+ ) cations. FTIR spectra of doped NiFe 2 O 4 exhibited the typical octahedral bands at 528.4 cm −1 which is the characteristic feature of spinel structure of spinel ferrites. The characterized spinel NiZr x Co x Fe 2-2x O 4 nano-ferrites were evaluated for their potential applications by magnetic hysteresis loops and dielectric measurements. The value of saturation magnetization ( M s ) decreased from 47.9 to 13.09 emu/g up to x =0.8 with ups and downs fluctuations in between x=0.0 to x=0.8. The high values of Ms of some compositions predicted the potential applications in high density perpendicular recording media and microwave devices. The frequency dependent behavior of permittivity (e') is recorded and discussed with the help of hopping mechanism of both holes and electrons. The dielectric and magnetic data of NiZr x Co x Fe 2-2x O 4 nano-ferrites suggested the potential applications of these ferrite nanoparticles in high frequency and magnetic data storage devices fabrication.