Magnetic behavior of gallium doped Zn<inf>0.95</inf>Co<inf>0.05</inf>O nanoparticles

Structural and magnetic properties of Zn0.95-xCo 0.05GaxO (x = 0.0 to 0.05) nanoparticles, synthesized by a novel sol-gel route followed by pyrolysis are studied. Powder X-ray diffraction data and TEM analyses confirm the formation of impurity free single phase wurtzite type ZnO structure for all the compositions. Pristine ZnO is diamagnetic and Zn0.95Co0.05O nanoparticles show weak paramagnetic behavior at room temperature. However, when Ga is co-doped with Co with x = 0.0 to 0.05 in Zn0.95-xCo0.05GaxO, a systematic increase in ferromagnetic moment is observed up to x = 0.03 at 300 K. Above x = 0.03 a decrease in ferromagnetism is observed. Copyright © 2011 American Scientific Publishers.