Influence of Oxygen Level on Structure and Ferromagnetism in Sn_0.95Fe_0.05O₂ Nanoparticles

This report discusses the effect of oxygen concentration at atmospheric pressure on the structural composition and ferromagnetism of nanoparticles of Fe doped SnO ₂ . Sn _0.95 Fe _0.05 O ₂ was annealed under controlled atmospheres with gradually increasing oxygen concentrations (varying O ₂ from 0 to 10 ⁶  ppm in N ₂ ). Prominent mass changes due to oxygen loss take place in the 0–5000 ppm range and the ferromagnetic properties. Ferromagnetism of Sn _0.95 Fe _0.05 O ₂ is inversely related to the oxygen concentration, which confirms the important role of oxygen vacancies this system. X-ray diffraction, thermogravimetric analysis, transmission electron microscopy, and magnetometry studies confirm that the observed changes in the ferromagnetic properties are due to changes in the oxygen stoichiometry.