Synthesis and Investigation of Electrical and Magnetic Properties of Cobalt doped Barium Monoferrite for High Frequency Applications

Abstract

Spinel structures are lately being explored widely because of their crucial applications in electromagnetic absorbing materials, high frequency devices, memory devices, photocatalysts and catalysts. The exponentially remarkable electrical and magnetic properties of ferrites have always been of prime interest which leads to their extensive commercial use. In present study barium monoferrite with formula Ba1-xCoxFe2O4 where x= 0.00 ,0.20 ,0.35 ,0.50 ,0.75, 1.00 has been prepared through sol gel auto-combustion method. Stoichiometric ratios of citric acid, barium, cobalt and iron nitrates along with ammonia solution for maintaining solution’s pH were used for the preparation of samples. Samples were calcinated at 800 °C for 4 hours. Sample characterization was made using X-Ray Diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR). Electrical and magnetic behaviors were analyzed through Vibrating sample magnetometer and RF impedance analyzer. Formation of Ba1-xCoxFe2O4 was confirmed using XRD. Crystallite sizes were calculated through Debye Scherer formula which lie in the range (26-40)±5 nm. Octahedral and tetrahedral band positions were confirmed using FTIR data. Room temperature frequency dependence of dielectric properties were observed to be enhanced till certain concentrations, then a decreasing trend was observed. Dielectric constant was increased from 5.7 to 16.7 for x=0.35 at 1MHz. The magnetic properties of prepared samples showed an increase in saturation magnetization from 2.69 emu/g at x=0.00 to 84.8 emu/g at x=1.00. A decrease in magnetic coercivity is observed with increase in concentration. The high and quite comparable values of dielectric constant make this material suitable for use as a microwave absorbing paint as well as a promising Electromagnetic Interference (EMI) shielding material.