Synthesized cobalt substituted magnetite (Co_xFe_3-xO₄) nanoparticles – evaluation of structural, optical, and magnetic properties for spintronics application

Abstract

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), field-emission 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.

Graphical Abstract

Keywords:

• Crystallite size
• spintronics material
• force constant
• FESEM
• optical energy band gap
• magnetic moment

Acknowledgment

The authors acknowledge the experimental work carried out at Dr. Babasaheb Technological University, Lonere; sample characterization of XRD carried out at B. K. Birla College of Arts and Science, Kalyan; FTIR characterization carried out at New Arts, Commerce and Science College, Ahmednagar; and FESEM, VSM, and UV-Vis characterizations carried out at SAIF, IIT Madras.

Disclosure statement

No potential conflict of interest was reported by the authors.