Agradecimentos: The authors (SKS & MK) are very grateful to Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) and Conselho Nacional de Desenvolvimento Cientíifico e Tecnológico CNPq (Brazil) for providing financial support. This work was also supported by a Korean Research Foundation Grant funded by the Ministry of Education & Human Resources Development (MOEHRD) (KRF-2008-005-J02703) Government of Korean Ver menos

Abstract: Polycrystalline Fe-doped Ce1-xFexO2-delta has been fabricated by using the standard solid state reaction technique in the concentration range 0 <= x <= 0.05. Reitveld refinement of the X-ray diffraction patterns shows a pure CeO2 phase when x <= 0.03, and the appearance of a secondary impurity phase of Fe2O3 beyond that. Furthermore, by doping Fe into CeO2 powder, the ferromagnetism can be significantly enhanced to a maximum value for x = 0.03, but degrades quickly with further doping. Magnetization results reveal that the large room-temperature ferromagnetism observed in Fe-doped CeO2 powder originates from a combined effect of oxygen vacancies and transition metal doping Ver menos