Magnetostriction of Fe-Cr-Co alloys

The room temperature linear saturation magnetostriction (λ
s
) and saturation magnetization per gram (σ
s
) were measured on polycrystalline samples of alloys containing from 30 wt% to 50 wt% chromium and up to 25 wt% cobalt. The data show that all the λ
s
are positive and that both λ
s
and σ
s
decrease with increasing chromium concentration. However, as the cobalt concentration is increased λ
s
displays an anomalous behavior at around 15 wt% cobalt. The room temperature λ
s
and σ
s
were also measured on a spinodally decomposed sample of the alloy with the composition 28 wt% Cr-10.5 wt% Co-Bal.Fe. In a spinodally decomposed material λ
s
and σ
s
will be the average λ
s
and σ
s
of the two phases present in the material. A fair agreement was found between the measured and the calculated λ
s
and σ
s
for the spinodally decomposed alloy indicating that the proposed compositions for the two phases are consistent with the magnetic measurements.