Influence of Milling upon the Magnetic Properties of the Intermetallic Compound MnAlGe

Abstract
The influence of milling upon some magnetic properties of the intermetallic compound MnAlGe has been studied. The Curie temperature of the material seems to be independent of particle size and is constant at 245°C. The saturation magnetization σs, which is 55 erg/Oe·g in the annealed state, decreases as the grinding time increases. The anisotropy field HA (∼43 000 Oe) was found to be more or less independent of the grinding time. Particles obtained by milling in a vibration mill can possess a coercivity IHC of about 3000 Oe, which can be enhanced by annealing to a value of 6400 Oe. The saturation magnetization and the coercivity decrease appreciably after mechanical loading which does not involve a reduction in particle size. This indicates that structural imperfections, rather than changes in particle size, play an important role in the observed phenomena.