Activation energy distribution in nanocrystallization kinetics of amorphous Fe73.5Cu1Nb3Si13.5B9 alloy

Nanocrystalline phase produced by suitable annealing of iron-based amorphous alloys known as Finemets shows extremely good soft magnetic properties. It is desirable to understand the mechanisms by which these materials crystallize in order to prepare relative stable materials for prospective applications. The presence of crystalline grains in the nanometer range in Finemet alloys is considered to be a consequence of processes of compositional and structural ordering. Therefore, the electrical resistivity variations occurring in amorphous alloys during the isothermal annealing are usually exploited to obtain information on the kinetics of the nanocrystallization process. Assuming inhomogeneities in the nanoscale range the authors applied the idea of Krueger and Woldt on isothermal resistivity transformation curves during the nanocrystallization of Fe73.5Cu1Nb3Si13.5B9. It will be presented that characterization by a rather simple distribution of activation energies is possible