Magnetic properties of the mechanically alloyed Fe 0.9-x Mn 0.1 Al x system

Abstract

Samples of nominal composition Fe0.9-xMn0.1Alx (0.1 ⩽ x ⩽ 0.5) were prepared by mechanical alloying starting from pure elements. Milling times of 24, 72 and 144 h were considered. The magnetic properties of the samples were studied by using 57Fe Mossbauer spectroscopy, vibrating sample magnetometry and magnetic susceptibility measurements. The phase distribution was determined from X-ray diffractometry. The 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 temperature between 10 K and 180 K suggest the occurrence of different types of transitions as the temperature is increased: (a) from a ferromagnetic to a paramagnetic phase, (b) from a reentrant spin-glass phase to a ferromagnetic one and (c) from spin-glass to a paramagnetic phase. These transitions are also strongly influenced by the milling time and the Al concentration.