CRYSTALLIZATION BEHAVIOR OF AMORPHOUS FE74CU1NB3SI10B12

The crystallization of Fe74Cu1Nb3Si10B12 alloy was studied by calorime try, thermomagnetic measurements and electron microscopy. In a first s tage, Fe(Si) nanocrystals with a mean size of about 10 nm precipitate in the amorphous matrix. After full crystallization, an Fe(Si) phase w ith a lower Si content and another boride-type phase are the main prod ucts, but other minority phases are also present. The low value of the Avrami index for the nanocrystallization reaction is related to some special features of the nucleation and growth mechanisms for FINEMET a lloys.