Magnetic behavior of nanoclusters of Fe-doped SnO2

A magnetic and structural characterization of SnO2 doped with 10 at% of Fe prepared by mechanical alloying is presented. X-ray diffraction indicates a good dissolution of Fe in the SnO2 structure, while Moessbauer spectroscopy shows that the doped material (where Fe atoms are in the +2 and +3 oxidation states) does not display a magnetically ordered pattern at room temperature. AC-susceptibility measurements present a behavior consistent with a system of magnetically coupled single-domain units, at the frontier between the behaviors of a cluster spin glass and of an interacting superparamagnetic (SPM) particle system. RT magnetization results display the typical shape of the SPM regime, although a weak hysteresis has been observed