Effect of structure distortion and oxygen vacancy on ferromagnetism in hydrothermally synthesized CeO2 with isovalent Zr4+ doping

Abstract The influences of isovalent Zr 4+ doping on structure and ferromagnetic property in hydrothermally prepared nanoscale CeO 2 are investigated. Results suggest that Zr ions tend to incorporate into substitutional sites and then occupy interstitial sites or the surface at a critical doping concentration. The substituted incorporation of Zr 4+ can significantly increase structure distortion and facilitate reduction of Ce 4+ and production of oxygen vacancies (V O ). With Zr doping, the saturation magnetization ( M S ) increases and then decreases, where the maximal M S appears at Ce 0.94 Zr 0.06 O 2 sample. Air annealing Ce 0.94 Zr 0.06 O 2 sample leads to the reduction of ferromagnetism. PL analyses reveal the emergent ferromagnetism may be closely related to structure distortion and V O defects induced by Zr on substitutional sites. The V O mediated F-center exchange mechanism can be used to interpret the RT ferromagnetic behavior in Zr-doped samples.