Magnetic Properties of Zn1-xCoxO Nanoparticles.

Abstract

Zn1-xCoxO nanoparticles have been synthesized at various concentrations of Co 2+ doping (0.005 x 0.15) by wet chemical method. Particle size was ranging from 34 -45 nm. The magnetic moment increases from x = 0.005 and 0.01 sample to x = 0.04 sample drastically showing a value of magnetic moment as high as 8.54 B/Cations and then decreases for x = 0.09 and 0.15 values of Co 2+ doping. There is almost paramagnetic behaviour for x = 0.005 and 0.01 Co 2+ doped samples. The x = 0.04 sample shows ferromagnetic ordering. Ferromagnetic behaviour decreases for x = 0.09 and 0.15 samples as the antiferromagnetic interaction dominates at higher Co 2+ doping concentrations. To probe the source of magnetism, we have undertaken photoluminescence studies also which revealed the presence of oxygen and Zinc vacancies along with other defects.