Transition from ferromagnetism to mictomagnetism in Fe—Al alloys

Ordering effects in the Fe-Al system

“…Progress have been registered in the dilution concentration range by Terakura [63]. In the high concentration range Jo and Akai [43] [40,49]. The magnetic behaviour is consistent with the observation of Gengnagel et al [36] (who have cooled very slowly their sample from 1000 OC to room temperature) and with the observation of Wakiyama [35] who obtained a saturation magnetic moment per Fe atom of 1.87 JlB.…”

“…Above c = 0.27 anomalous magnetic properties have been registered since 1959 by Arrott and Sato [32] and reconsidered later in particular by Shull et al [40]. In this concentration range the alloys can have the a, B2 or D03 structure depending on the temperature range considered, D03 corresponding to the low temperature phase.…”

“…For instance Allen and Cahn [24] [24][25][26]. Therefore [40,41], the magnetic phase diagram for 0 c 0.5 shows paramagnetic, ferromagnetic and spin-glass regimes; the corresponding transition lines meet at a multicritical point near c = 0.30 [40]. The magnetic behaviour depends strongly upon the phase state and upon the atomic arrangement i.e.…”

“…In this concentration range the alloys can have the a, B2 or D03 structure depending on the temperature range considered, D03 corresponding to the low temperature phase. Shull et al [40] studied alloys which have been quenched from 1200 OC and then annealed at the appropriate temperature in order to obtain the B2 or D03 structure. The alloy Feo.73AI0.27 D03 I is a pure mictomagnet (see [62] We show also preliminary results of a study of ordered single crystals.…”

Effect of Adding of V and Co Atoms on the Spin Glass Transition Temperature of Fe0.7-xMxAl0.30Alloys

“…Lo w Ùeld ac suscepti bi l ity and dc m agneti zati on measurem ents as functi on of tem pera ture ( ) and concentra ti on ( ) further establ ish the pha se di agra ms and the nature of ato m ic orderi ng i n Fe{ Al al l oys [15]. Careful studi es of ato m i c order i n Fe Al al l oys wi th near to 0.30 reveal ed b oth FeAl and Fe Al typ e order wi th di˜erences i n Fe and Al arra ng ements i n the two cases [16,17].…”