Magnetic properties of the mechanically alloyed Fe0.9-xMn0.1Alx system

Samples of nominal composition Fe0.9-xMn0.1Alx (0.1 less than or equal to x less than or equal to 0.5) were prepared by mechanical alloying starting f rom pure elements. Milling times of 24, 72 and 144 h were considered. The m agnetic properties of the samples were studied by using Fe-57 Mossbauer spe ctroscopy, vibrating sample magnetometry and magnetic susceptibility measur ements. The phase distribution was determined from X-ray diffractometry. Th e so obtained results evidence a strong dependence on the milling time and Al concentration of the room-temperature hyperfine field distributions and coercive forces. The susceptibility measurements in the range of temperatur e between 10 K and 180 K suggest the occurrence of different types of trans itions as the temperature is increased: (a) from a ferromagnetic to a param agnetic phase, (b) from a reentrant spin-glass phase to a ferromagnetic one and (c) from spin-glass to a paramagnetic phase. These transitions are als o strongly influenced by the milling time and the Al concentration.