Structural, electrical, and magnetic properties of Co-substituted Ni_1-xCo_xFe₂O₄ (x = 0.1, 0.2, and 0.3) nanocrystalline ferrites

Abstract

Nanocrystalline ferrites are interesting materials due to their rich physical and electromagnetic properties. In the present work, Ni_1-xCo_xFe₂O₄ (x = 0.1, 0.2, and 0.3) nanocrystalline ferrites have been synthesized by solgel auto-combustion method and their microstructural, magnetic, and dielectric properties have been synthesized. The structural properties of synthesized ferrites are determined by using X-ray powder diffraction, scanning electron microscope, and Fourier transform infrared spectroscopy. The cation distribution obtained from X-ray diffraction shows that cobalt occupies only tetrahedral site in spinel lattice. The lattice constant of nickel ferrite increases with the increase in cobalt content. The structural parameters like bond lengths and tetrahedral and octahedral edges have been varied by cobalt substitution. The microstructural study carried out by using SEM technique showed that the average grain size increased with cobalt concentration. The initial permeability (μ_i) increased with increasing cobalt concentration. The observed g-value from ESR is approximately equal to standard value. From hysteresis curve, the saturation magnetization (M_s), coercivity (H_c), and magnetic moment (μ_B) are obtained as a function of cobalt concentration.

Keywords:

• Cation distribution
• initial permeability
• spinel structure
• ESR
• ferrites

Acknowledgment

The authors are grateful to Department of Science and Technology (DST), Government of India, New Delhi, for providing financial support through (DST)-Promotion of University Research and Scientific Excellence (PURSE) program.