High resolution electron microscopy studies of the microstructure in nanocrystalline (Fe0.99Mo0.01)Si9B13 alloys

The crystallization process of an amorphous (Fe0.99Mo0.01)78Si9B13 alloy was examined by high resolution electron microscopy. Experimental results show that nanocrystalline alloys with average grain sizes in the range 30–50 nm are obtained after annealing at 560–620°C for 1 h, and four phases — α-Fe(Si,Mo), (Fe, Mo)3B, (Fe,Mo)23B6 and Fe2B — coexist in the sample. Most of the Fe2B crystals are found no nucleate at the interfaces between α-Fe(Si,Mo) grains and the residual amorphous phase at 620°C. No disordered regions and nanovoids were detected at the grain boundaries. Defect structures in the nanocrystalline alloys are also discussed.