Structural, optical and magnetic properties of cobalt oxide nanoparticles synthesized by simple combustion method

Abstract

Cobalt oxide nanoparticles were synthesized by a microwave combustion method (MCM) for the first time, using urea as the fuel. The prepared samples were examined by XRD, HRSEM, HR-TEM, UV-Visible spectra, and VSM. XRD analysis indicated well-crystallized cubic phase. HR-TEM images showed that the Co3O4 nanoparticles have sphere-like structure with the average particle size in the range of 25-50 nm. Optical properties of Co3O4 nanoparticles revealed the presence of two band gap (1.75 and 2.32 eV) values, which confirmed the purity and semiconducting properties. The VSM measurements revealed a small hysteresis loop at room temperature indicating a ferromagnetic nature.