Local structure changes on annealing in an Fe-Si-B-P bulk metallic glass

Local structure changes on annealing of soft magnetic Fe₇₆Si₉B₁₀P₅ metallic glass was examined using transmission electron microscopy. Medium-range order regions in glass states were clearly developed on annealing for structural relaxation below the glass-transition temperature which leads a decrease of magnetic coercivity as well as a physical density. Nanobeam electron diffraction analysis revealed that the medium-range order structure developed on annealing has no structural order of the primary crystal with a long-period complex structure. The relaxed glass can be regarded as a specific state which is characterized by medium-range order structures.