Structural and compositional stability of the mechanically alloyed (Fe, Mo)-Al at elevated temperatures

The powdered sample milled 32 h, sample denoted as S/32, has yielded the finest structure of homogeneously distributed elements and quasi-binary bcc-(Fe,Mo)-Al composition well-established by the elemental maps measured by an energy-dispersive X-ray spectroscopy. This sample was stable also during a treatment at elevated temperatures as both in-situ X-ray diffraction and thermomagnetic measurements have evidenced. On the other hand, the next 32 h of milling (in sum 64 h; sample S/64) has led to a partial decomposition and the small Al and Mo peaks reappeared in diffraction patterns. The behavior of this sample at elevated temperatures is compared with the previous one and moreover, with the sample after 16 h of milling (S/16) which has yielded similarly the Al and Mo diffraction peaks. Despite the structural/compositional states of the S/16 and S/64 samples seem to be during thermal treatment similar, their magnetic behavior is different and none of them achieves the properties of S/32 sample.