Temperature and field dependence of the magnetization of Fe–Al powders in cold-worked and annealed state

Magnetic behaviour of unannealed and annealed Fe-Al powders has been investigated as a function of field and temperature in the concentration range 0 to 50 at% Al. The magnetization M of unannealed powders (measured at 20 K) decreases monotonously with increasing Al contents up to 30 at% according to a dilution law; at higher Al contents the magnetization decrease is stronger than by magnetic dilution and vanishes at about 50 at% Al. The magnetization of annealed powders already vanishes at about 38 at% Al. M vs. T curves of annealed powders (30 to 36 at% Al) show a maximum at 150 to 250 K. This maximum does not occur in corresponding unannealed powders.