Thermomagnetic detection of recrystallization in FeCoNbBCu nanocrystalline alloys

The recrystallization process in FeCoNbBCu nanocrystalline alloys is evidenced from thermomagnetic results as a significant decrease in magnetization at the second crystallization stage. The lowering in the volume fraction of α-FeCo crystals indicates that some of these crystals contribute to the boride phases formed. Electron microscopy images reveal that the final microstructure consists of large crystals (∼500 nm) of a fcc (FeCo)23B6 phase and small crystals (∼20 nm) of bcc α-FeCo and of some boride phases as such (FeCo)2B.