Impacts of Ni–Co substitution on the structural, magnetic and dielectric properties of magnesium nano-ferrites fabricated by micro-emulsion method

•  Mg1-xNixCoyFe2-yO4 nano ferrites were successfully fabricated by cheap route.
• The magnetic behavior was increased up to x = 0.4.
• Mg0.6 Ni0.4 Co0.4 Fe1.6O4 nano-ferrite can be used in high frequency devices.

Magnesium ferrite (MgFe2O4) nano-structures doped with Ni–Co at magnesium and iron sites respectively were fabricated by the micro-emulsion method and characterized by the X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM) and dielectric measurements. The analysis of XRD patterns confirm the single phase spinel structure and the crystallite size calculated by Scherer’s formula lies in the range of 15–26 nm. The spectral studies elucidate the characteristic feature of spinel phase. The real and imaginary parts of dielectric constant and dielectric loss exhibit peaking behavior. The dielectric properties have been explained on the basis of Debye-type relaxation phenomenon in accordance with Koop’s phenomenological theory. The increase in the tendency of saturation magnetization is consistent with the enhancement of crystallinity. The crystallite size is small enough to obtain considerable signal to noise ratio in the recording media. The optimized dielectric and magnetic parameters suggest that the material with composition Mg0.6 Ni0.4 Co0.4 Fe1.6O4 may be used for applications in recording media and microwave devices.

Ni–Co substituted magnesium ferrite (Mg1−x Niy Fe2−y Coy O4) nano-structures were successfully fabricated by a cheap route. The Mg0.6 Ni0.4 Co0.4 Fe1.6O4 (x, y = 0.4) nano-ferrite exhibited the maximum magnetic behavior and minimum dielectric behavior, that suggested their applications in devices working at GHz frequencies.Figure optionsDownload as PowerPoint slide