Effect of annealing conditions on the Fe incorporation and ferromagnetism of Sn1−xFexO2: A Raman spectroscopic investigation

In order to investigate the effect of annealing conditions on the structural and magnetic properties, we have employed detailed Raman spectroscopic investigations on 5% Fe-doped SnO2 samples annealed at different temperatures in the range 200–900°C. Systematic changes observed in the Raman spectra with increasing annealing temperature are correlated with similar changes in the structural and magnetic properties of these samples. The presence of incorporated Fe ions was confirmed from the appearance of vibrational local modes of Fe in the Raman spectra. It is concluded that the ferromagnetism in Sn0.95Fe0.05O2 annealed in the 350–600°C temperature range is due to the incorporated Fe ions and is destroyed completely when TA>600°C due to the expulsion of Fe from the SnO2 lattice, which is in agreement with the disappearance of the Fe local modes in the Raman spectra.