Clusters; annealing; electron microscopy; room temperature ferromagnetism Clusters; annealing; electron microscopy; room temperature ferromagnetism
1Department of Physics, University of Petroleum & Energy Studies, Dehradun 248007, India
2Department of Physics, Indian Institute of Technology Roorkee, Roorkee 247667, India
Adv. Mater. Lett., 2012, 3 (2), pp 107-111
Publication Date (Web): Apr 14, 2012
Copyright © IAAM-VBRI Press
We report on the effect of different gaseous environments (air, argon and Ar/H2) on the structural and magnetic properties of Zn0.98Co0.02O synthesized by the solid state reaction route. We have also studied the effect of different annealing times and temperatures on the as synthesized samples. M-H curves of the air sintered and the argon annealed samples show paramagnetic behavior whereas the samples annealed in the hydrogenated argon (Ar/H2) environment exhibit ferromagnetic property at room temperature. Based on the structural and magnetic properties it has been found that Co metal clusters are responsible for the observed room temperature ferromagnetism (RTFM) in the hydrogenated samples.
Clusters, annealing, electron microscopy, room temperature ferromagnetism