Synthesized cobalt substituted magnetite (CoxFe3-xO4) nanoparticles - evaluation of structural, optical, and magnetic properties for spintronics application.

Cobalt-substituted magnetite Co_xFe_3-xO₄ nanoparticles were synthesized using a sol-gel auto-combustion method using citric acid as a fuel. The samples were characterized by X-ray diffraction (XRD), fieldemission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) spectroscopy, optical ultraviolet-visible (UV-Vis) spectroscopy, and vibrating sample magnetometer (VSM). XRD studies revealed cobalt replacing iron, forming a single phase with a crystalline size of 17-25 nm. FESEM and FTIR spectra showed a metal-oxygen bond, while UV-Vis spectra showed absorbance spectra and Kubelka-Munk theory. Magnetic properties were studied using VSM, revealing increased saturation magnetization and a constant squareness ratio, confirming the single domain of cobalt-doped Fe₃O₄ nanoparticles. These nanoparticles have potential applications in spintronics, nanoscale devices, and supercapacitors. [ABSTRACT FROM AUTHOR]