Effect of Chromium and Cobalt Addition on Structural, Optical and Magnetic Properties of NiO Nanoparticles

Nanocrystalline nickel oxide (NiO), chromium and cobalt doped NiO nanoparticles have been prepared successfully by chemical precipitation method. NiO, Cr and Co-doped NiO nanoparticles have been characterised using various analytical techniques such as X-ray diffraction, FESEM, HRTEM, UV absorption and M-H curves. The average grain size of NiO, Cr and Co-doped NiO nanoparticles are 10.33 nm, 9.54 nm and 8.70 nm respectively. The UV absorbance study shows a strong absorption edge at 314.96 nm, 308.64 nm and 305.37 nm respectively. The band gap values of NiO, Cr and Co-doped NiO nanoparticles are 3.936 eV, 4.017 eV and 4.060 eV. The incorporation of chromium and cobalt into NiO nanoparticles have strongly influenced the magnetic behaviour and the material got converted from super paramagnetic to ferromagnetic material.