Abstract Amorphous specimens of Fe 78 Si 9B 13 have been treated by ultrashort pulse current. It was obtained that the α Fe(Si) single phase structure precipitated from the amorphous matrix of Fe 78 Si 9B 13 by adjusting the parameters of pulse current. It can be considered that the single phase crystallization results from the periodic repulsion between the moving electrons and the vacancy like structural defects in the amorphous parts.That is,the repulsive effect causes the met...