Nanocrystalline phases, produced by several techniques, are known to show interesting physical properties. A mixture of very fine bcc Fe grains embedded in an amorphous matrix reveals excellent soft magnetic properties [1]. Such a mixture can be easily obtained during crystallization of the amorphous phase if the growth of the crystals is inhibited [2].
Samples of amorphous Fe$_{73.5}$Cu$_{1}$Nb$_{4.5}$Cr$_{5}$B$_{16}$ were prepared by the spinning wheel technique in the form of ribbons. The formation of a nanocrystalline bcc solid solution during crystallization of the amorphous alloy was studied by X-ray diffraction and DTA analysis.
DTA traces of samples revealed several exothermal processes. The first one, starting at about 754K, is due to the formation of the bcc Fe solid solution while the others, at temperatures above 910 K are probably associated with the formation of boride phases.
The profile of the Fe$_{\alpha}$ (110) diffraction peak (after elimination of the remaining amorphous phase contribution) was fitted by split Pearson VII profile function using program SHADOW [3]. The analysis was performed for samples after various heat treatment in the temperature region of the first DTA peak. The volume part of the remaining amorphous phase as well as the average grain size for the nanocrystalline phase were determined using XPZ program [4].
1. Y. Yoshizawa, S. Oguma, K. Yamauchi: J. Appl. Phys. 64,
(1988), p. 6044
2. Y. Yoshizawa, K. Yamauchi: Mat. Sci. Eng., A 133 (1991),
p. 176
3. S. Howard, R. L. Snyder: Advances in Materials
Characterization II},
Material Science Research {\bf 19}, edited by R. L. Snyder,
R. A. Condrate, Sr., and P. F. Johnson (Plenum Press, New York,
1985), p. 57-71
4. V. Kavecansky: XPZ --- program for X--ray data processing,
(to be published)