Glassy magnetism in mechanically alloyed FexCr90−xMn10 (x=18 and 35)

X-ray diffraction (XRD), 57Fe Mössbauer and magnetic measurements were performed on mechanically alloyed FexCr90−xMn10 (x=18 and 35) alloys. XRD and 57Fe Mössbauer spectra show the systems are non-magnetic BCC phase. The irreversibility between field-cooled and zero-field-cooled magnetization curves at relative high temperature is due to the blocking of some single particles. A correlation between the Fe concentration and Tmax of ZFC curves can be explained by the fine Fe-rich clusters which are embedded in a paramagnetic solid solution. The Fe35Cr55Mn10 alloy exhibits two type of blocking/freezing in an ensemble of nanoparticles. With the decreasing of temperature, the Fe18Cr72Mn10 alloy shows spin-glass-like behavior and the Fe35Cr55Mn10 alloy goes through two magnetic transitions from paramagnetic phase to ferromagnetic phase and then to re-entrant spin-glass state.