NUKLEONIKA 2004, 49(Supplement 3):s79-s83

MICROSTRUCTURE STUDIES OF AMORPHOUS AND NANOCRYSTALLINE (Fe1-xCox)85.4Zr6.8-yMyB6.8Cu1 (x = 0 or 0.1, y = 0 or 1, M = Mo, Nb or Nd) ALLOYS

Jacek Olszewski1, Józef Zbroszczyk1, Hirotoshi Fukunaga2, Wanda Ciurzyńska1, Jan Świerczek1, Mariusz Hasiak1, Kamila Perduta1, Agnieszka Łukiewska1, Alina Młyńczyk1

1 Institute of Physics, Częstochowa University of Technology, 19 Armii Krajowej Ave., 42-200 Częstochowa, Poland,
2 Faculty of Engineering, Nagasaki University, Nagasaki 852-8521, Japan

The amorphous and nanocrystalline (Fe1-xCox)85.4Zr6.8-yMyB6.8Cu1 (x = 0 or 0.1, y = 0 or 1, M = Mo, Nb or Nd) alloys were studied using Mössbauer spectroscopy. We have stated that after the low temperature annealing of the samples the decrease of the average hyperfine field due to the Invar effect was observed. This effect is associated with the increase of atom packing density after the annealing of the samples, which may lead to the noncolinear spin state in some regions. This phenomenon was completely suppressed after substitution of 10% of Fe atoms by Co atoms. At early stages of crystallization of the Fe85.4Zr6.8-yMyB6.8Cu1 (y = 0 or 1, M = Mo, Nb or Nd) alloys, the interfacial zone is poor in iron due to diffusion of Zr, B, Nb, Mo and Nd atoms outside regions where a-Fe fine grains are created. However, the iron content in the amorphous matrix is the same as in the as-quenched state. The iron concentration in the interfacial zone of the nanocrystalline alloys obtained by the accumulative annealing depends on the chemical composition of the as-quenched samples. In the nanocrystalline samples obtained by two-step annealing, the iron content in the interfacial layer is higher than in the amorphous matrix.