THE INFLUENCE OF CU AND NB ON THE CRYSTALLIZATION PRODUCTS OF ANNEALED FECUNBSIB

Depending on different Nb and Cu concentration, we studied the formati on of nano- and microcrystalline phases in differently annealed sample s of FeCuNbSiB. First, the kinetics of crystallization was explored by measuring the temperature-dependent electrical resistivity and magnet ization. After this, we collected Mossbauer spectra and did an X-ray d iffraction analysis of annealed samples at chosen temperatures to disc over the different crystalline phases. It was found how the onset of c rystallization had been shifted towards other temperatures. The analys is of Mossbauer spectra shows that building up the well-known DO3 stru cture of Fe3Si is disturbed in the alloy without Cu. At higher Nb cont ent, we resolve two different crystallization steps in the formation o f Fe3Si and a new crystalline phase, probably being a structure like F e23B6.