New Mg0.5CoxZn0.5−xFe2O4 nano-ferrites: Structural elucidation and electromagnetic behavior evaluation

• Published in: Current applied physics Vol. 14; no. 5; pp. 716 - 720
• Main Authors: Lodhi, Maria Yousaf, Mahmood, Khalid, Mahmood, Azhar, Malik, Huma, Warsi, Muhammad Farooq, Shakir, Imran, Asghar, M., Khan, Muhammad Azhar
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2014
• Subjects: Dielectric properties; Magnetic properties; Micro-emulsion technique; Nano-ferrites; XRD; XRD; Nano-ferrites; Dielectric properties; Micro-emulsion technique; Magnetic properties
• ISSN: 1567-1739; 1878-1675
• DOI: 10.1016/j.cap.2014.02.021

In this work cobalt substituted magnesium zinc nanocrystalline spinel ferrites having general formula Mg0.5CoxZn0.5−xFe2O4 where x = 0.1, 0.2, 0.3, 0.4, 0.5 were synthesized using micro-emulsion technique. The Co substituted samples annealed at 700 °C and characterized by various characterization techniques, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), dielectric measurements and vibrating sample magnetometer (VSM). XRD analysis confirmed single phase spinel structure and the crystalline size calculated by Scherrer's formula found to be in 21.38–45.5 nm range. The lattice constant decreases as substitution of Co is increased. The decrease in lattice constant is attributed to the smaller ionic radius of cobalt as compared to zinc ion. The FTIR spectra reveled two prominent frequency bands in the wave number range 400–600 cm−1 which confirm the cubic spinel structure and completion of chemical reaction. The dielectric parameters were observed to decrease with the increased Co contents. The peaking behavior was observed beyond 1.8 GHz. The frequency dependent dielectric properties of all these nanomaterials have been explained qualitatively in accordance with Koop's phenomenological theory. Magnetic studies revealed that the coercivity (Hc) attains maximum value of 818 Oe at ∼21 nm. The increasing trend of magnetic parameters (coercivity and retentivity) is consistent with crystallinity. The crystallite size is small enough to attain considerable signal to noise ratio in high density recording media. The optimized magnetic parameters suggest that the material with composition Mg0.5Co0.5Fe2O4 may have potential applications in high density recording media. [Display omitted] Nanocrystalline Mg0.5CoxZn0.5−xFe2O4 soft ferrites prepared by micro-emulsion technique and crystallite size decreased from in 21.38–45.5 nm range upon the doping of cobalt. The magnetic parameters were appreciably optimized. Higher value of coercivity suggests the utility of these nanomaterials in high density recording media. •Nanocrystalline Mg0.5CoxZn0.5−xFe2O4 ferrites were fabricated by micro-emulsion technique.•Impact of cobalt substitution on various properties has been studied in detail.•Mg0.5CoxZn0.5−xFe2O4 nanomaterials exhibited optimized magnetic parameters.