Valence state dependent room-temperature ferromagnetism in Fe-doped ceria nanocrystals

Dohčević-Mitrović, Z. D.; Paunović, N.; Radović, M.; Popović, Z. V.; Matović, B.; Cekić, B.; Ivanovski, V.
May 2010
Applied Physics Letters;5/17/2010, Vol. 96 Issue 20, p203104
Academic Journal
Room-temperature ferromagnetism was observed in undoped and Fe2+(3+)-doped CeO2 nanocrystals. In Fe-doped samples the enhancement of ferromagnetic ordering occurs by changing the valence state of Fe ions, whereas Raman spectra demonstrated strong electron-molecular vibrational coupling and increase in oxygen vacancy concentration. Air annealing showed degradation of ferromagnetic ordering and appearance of hematite phase in Fe3+-doped sample. The observed ferromagnetic coupling in Fe-doped samples, associated with the presence of magnetic ions mediated by single charged O2- vacancies, demonstrated that valence state of dopant has a strong influence on magnetic properties of CeO2 nanoparticles.


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