Microstructure and ferromagnetism of Co-doped CeO2 nano-octahedrons

•Co-doped CeO2 nano-octahedrons have been synthesized for the first time by a simple co-precipitation method.•Room temperature ferromagnetism was obvious enhanced with increasing the amount of Co ions.•Remarkable RTFM should make CeO2 nano-octahedrons excellent candidates for applications in related areas.

Co-doped CeO2 nano-octahedrons of about 500 nm in edge length have been synthesized by a simple co-precipitation method. XRD, SEM, TEM, Raman scattering and M-H curves were employed to characterize the samples. The results showed that all the samples have a fluorite cubic structure and the nano-octahedrons transform into the mixed morphology of nano-octahedrons and nanorods with the participation of Co. It is found that there are Ce3+ ions and oxygen vacancies in the surface of non-doped CeO2 octahedrons. The magnetic measurements indicated that Co-doped CeO2 samples exhibit excellent ferromagnetism, and while increasing the amount of Co ions, the ferromagnetism increase more, which can be associated with the presence of Ce3+ and Co3+.