Background: The study of the diluted ferromagnetic semiconductors with a curie temperature well above room temperature has been paid too much attention

which has potential applications in spin electronics. Purpose: For a better understanding of the origin of the ferromagnetism

especially in the presence of O vacancies

the microscopic electronic structure and hyperfine fields are required. Methods: An ab initio calculations magnetic hyperfine fields in the Fe doped SnO2 were performed by the Wien2k code embodying the full-potential linearized augmented plane-wave method for two charge states of the impurity that occupies two different cases of the neutral impurity state Fe0and the charged acceptor state Fe1? or Fe2?. The Fe doped SnO2 can provide one or two electrons via oxygen donor vacancies. Results: The present results illustrate clearly that the energy level splitting of the Fe-3d orbit with O vacancies and without O vacancies for the (SnO2)15FeO2+1e and (SnO2)15FeO2+2e valences resulted in the increasing of the unpaired electrons and the leading of Fe atoms into the high spin states

producing the giant magnetic moment. Conclusion: The calculated Fe magnetic moment for the (SnO2)15FeO2+1e is 5μB

which is consistent with the magnetic moment of 5.1μB measured by the M?ssbauer spectroscopy. Abstract