Magnetic and optical properties of cobalt-doped hematite nanoparticles of logas natural sand for environmental application

Abstract

The cobalt doped hematite (α-Fe2O3) nanoparticles have been prepared by ball milling method using Logas natural sand as a raw material. The milled hematite nanoparticles were doped using cobalt with concentration of 0, 5, 10, 15 and 20 wt. %. The optical, structural and magnetic properties were studied using Uv-Vis spectroscopy, X-ray diffractometer (XRD), and vibration sample magnetometer (VSM), respectively. The optical properties strongly depend on cobalt content and showed that the band gaps of cobalt doped hematite decrease with increasing cobalt content. The samples exhibited weak ferromagnetic behaviour with the coercivity ranged from 124 Oe to 299 Oe. The XRD measurements confirmed the formation of crystalline, rhombohedral crystal structure and hematite nanoparticles. The samples show cobalt-hematite nanoparticles as indicated through XRD measurement. The average crystallite size calculated using Scherrer formula found to be 38.51, 35.67, 33.75, 32.73 and 31.53 nm after being doped with cobalt 0, 5 and 10, 15 and 20 wt. %, respectively. Some other elements such as silicon and titanium and others elements were detected, which demonstrates that these milled samples are not purely hematite as confirmed by X-Ray Fluorescence Spectroscopy (XRF) results.