V. Cremaschi et al., Huge magnetic hardening ascribed to metastable crystallites during first stages of devitrification of amorphous FeSiBNbSn alloys, J MATER RES, 15(9), 2000, pp. 1936-1942
A huge magnetic hardening (i.e., increase of coercivity from 5 A/m up to 4.
4 kA/m) was reported for Fe75Si11B10Nb3Sn alloy ribbons during their very f
irst stage of crystallization from an initial amorphous state. In contrast,
Fe78Si11B10Sn1 showed no such hardening, while a moderate hardening was ob
served for Fe76Si11B10Nb3. This outstanding change was ascribed to the gene
ration of metastable nanocrystallites that disappear upon heating at higher
temperatures. A noticeable softening was then recovered (with a decrease o
f coercivity down to 0.8 kA/m) once the optimum homogeneous conventional na
nocrystalline phase was achieved. Both structure and magnetic evolutions ar
e followed by different techniques.