Additional Y³⁺ Doping Effect on Ferromagnetism of Ce_0.97Co_0.03O_2-δ Compounds

Y³⁺ doping effect on magnetic roperties of Ce_0.97Co_0.03O_2-δ are examined.
Vibrating sample magnetometer (VSM) measurements indicate that e_0.97Co_0.03O_2-δ is ferromagnetic at room temperature. The saturated magnetization M_S is altered by additional Y³⁺ doping, i.e., with the increase of the amount of Y³⁺ doping concentration in Ce_0.97-yY_yCo_0.03O_2-δ (y=0.01, 0.05 and 0.10), M_S increases persistently. Raman spectra measurements
indicate that additional oxygen vacancies are introduced with the amount of Y³⁺ doping content. The results can be well elucidated by the F-centre exchange coupling (FCE) mechanism proposed recently, thus they are important for understanding the ferromagnetism origination in transitional metal-doped insulating oxides.