Effect of oxygen vacancy and dopant concentration on the magnetic properties of high spin Co2+ doped TiO2 nanoparticles

► Oxygen vacancy induces ferromagnetism in cobalt doped anatase TiO2 nanoparticles. ► On air annealing the sample loses ferromagnetism giving rise to paramagnetism. ► Saturation magnetization decreases at higher doping concentration. ► Blocking of magnetic moment occurs due to the presence of cobalt clusters.