Magnetic and structural studies of amorphous Al-Cu-Mn-Ge alloy synthesized by mechanical alloying

摘要

The signature of ferromagnetism in Al-based icosahedral and related metastable alloys has stimulated a lot of activity in the field of quasicrystals [1-3]. A weak ferromagnetic behaviour has been reported in icosahedral and amorphous Al-Mn-Si alloys with a high content of silicon or other metalloid (>25 at%), when synthesized by melt spinning [4]. This system, in the amorphous state, exhibits a Curie temperature wlOOK, while in the quasicrystal state it shows a transition temperature "110K. Ferromagnetic behaviour in Al4oCuioMn2sGe25 has been reported in both the quasicrystal as well as the distorted crystalline phase with different values of magnetic parameters [5,6]. Magnetization values up to 20 Am2/kg have been reported in Al-Cu-Mn-Fe-Ge quasicrystals [7].