Nucleation Behavior of α-Fe in Amorphous Fe-7Zr-5B-1Au Alloy

The effect of 1 at.% Au addition on the primary crystallization of the Fe-7Zr-5B amorphous alloy has been studied by Atom Probe Field Ion Microscopy (APFIM) and Transmission Electron Microscopy (TEM). No Au enriched clusters were found before primary crystallization. During the nucleation and growth stage of primary alpha-Fe, Au clusters were observed by tomographic atom probe (TAP). However, alpha-Fe particles did not form at the site of Au cluster. Hence, Au does not enhance the nucleation density of alpha-Fe crystals in Fe-7Zr-5B-1Au alloy, unlike Cu does in FINEMET and Fe-Zr-B amorphous alloys. In fact, TEM observations indicated no difference between the nanocrystalline microstructures of Fe-7Zr-5B-1Au and Fe-7Zr-5B alloys after annealing at 650 degrees C for 60 min.