J. Phys. IV France 08 (1998) Pr2-191-Pr2-194
Magnetoelastic properties of amorphous and nanocrystalline Co-Fe-Nb-B alloysV. Soyka, L. Kraus and K. Záveta
Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 180 40 Praha 8, Czech Republic
The saturation magnetostriction constant, λs, and ΔE of amorphous and nanocrystalline CoxFe93-x-yNb7By alloys (17 ≤ x ≤ 33.9 ≤ y ≤ 15) were studied. Different stages of nanocrystallisation were obtained by field- and conventional annealing at different temperatures. On nanocrystallisation αs slightly decreases but the minimum αs always exceeds 18 ppm. The maximum ΔE is observed for annealing temperatures 400 - 450°C, i.e. before or at the early stage of nanocrystallisation. With the development of nanocrystalline phase ΔE decreases. In the field-annealed samples quite a large in-plane anisotropy transversal to the ribbon axis was observed. On the other hand, some conventionally annealed ribbons exhibit magnetic anisotropy perpendicular to the ribbon surface. The results are discussed in terms of the phenomenological model developed by Squire.
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