Effect of Co doping on the physical properties of Co-doped ZnO nanoparticles

Cobalt-doped (1-5 wt%) ZnO nano-particles have been fabricated by sol-gel route. Fourier Transform Infrared Spectroscopy shows that Co has successfully substituted Zn in ZnO lattice. The average optical transmittance of the nanoparticles is found to be > 75% in the visible region. These transparent semiconductor nanoparticles retain a band gap in the ultraviolet (3.99-3.2 eV) and high transparency across the Co doping range of (1-5 wt%). Co doped ZnO nanoparticles show room-temperature ferromagnetism. Surface study shows that nanoparticles are porous in nature. The grain size of the nanoparticles is varied between 33 and 63 nm.