Based on a knowledge of the NMR spectra for FeB, Fe2B, orthorhombic Fe3B (o-Fe3B), and body-centered-tetragonal Fe3B (bct-Fe3B), the phases produced during the annealing of Fe-B amorphous alloys can be identified with greater sensitivity by NMR techniques than by x-ray diffraction. In the present work, a combination of x-ray diffraction experiments and spin-echo NMR measurements of the hyperfine field distributions for the 10B, 1 1B, and 57 Fe nuclei has been performed on both as-quenched and annealed Fe100 -xBx (14≤x≤25) amorphous alloys. In general terms, it was found that annealing at temperatures near 400°C resulted in crystallization products which included bct-Fe3B, while annealing at approximately 800°C leads to the formation of o-Fe 3B. The behavior of the B hyperfine field indicates that, for the Fe100-xBx amorphous alloys, an o-Fe3B-like local order is favored in the low B concentration regime, and a bct-Fe3B-like local order is favored in the high B concentration regime.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)