XPS studies and ferromagnetism evaluations of pure MgO and Fe- and Co-doped MgO nanoparticles

Abstract

Magnesium oxide nanoparticles (MgO-NPs), as well as Fe- and Co-doped MgO-NPs, were synthesized using a gelatin-based sol–gel method. The structure and morphology of the prepared samples were examined using X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The results indicated that pure and doped MgO-NPs, with particle sizes below 100 nm, crystallized in cubic structures. XRD data were analyzed using the size-strain plot (SSP) method, revealing that doping increased the lattice strain to 0.11 for pure MgO, 0.18 for Co-doped, and 0.13 for Fe-doped MgO nanoparticles. The crystallite sizes were found to be 60 nm for pure MgO, 48 nm for Co-doped, and 60 nm for Fe-doped MgO nanoparticles. X-ray photoelectron spectroscopy (XPS) was used to investigate the oxidation states of the prepared samples. The Fe-doped MgO-NPs exhibited the highest value of oxygen vacancy states, indicating more defects compared to the other samples. The saturation magnetization (Ms) was measured to be 0.026 emu/g for pure MgO, 0.45 emu/g for Co-doped, and 0.62 emu/g for Fe-doped MgO nanoparticles.