Near Zero Magnetostrictive Nanocrystalline Fe-Si-B-Cu-Nb Alloys with a High Heating Rate Annealing

A nanocrystalline Fe
73.5
Si
15.5
B
7.0
Cu
1.0
Nb
3.0
alloy has near zero magnetostriction (λ
s
), a high saturation magnetic flux density (B
s
) of 1.23 T and a low coercivity (H
c
) of about 2.5 A/m. Higher B
s
than 1.23 T maintaining near zero λ
s
has been researched with a high heating rate annealing. Near zero magnetostriction with a high heating rate is found in Fe-based nanocrystalline alloys having Si/Fe ratio of about 0.21. Moreover, nanocrystalline Fe-based alloys having about 18at%Si in the α-Fe phase show near zero λ
s
which is close to that of a nanocrystalline Fe
73.5
Si
15.5
B
7.0
Cu
1.0
Nb
3.0
alloy. Saturation magnetic flux density of 1.38 T having near zero λ
s
is realized with a nanocrystalline Fe
76.4
Si
16.6
B
6.0
Nb
1.0
alloy. However, nanocrystalline Fe
76.4
Si
16.6
B
6.0
Nb
1.0
alloy has a crystalline grain size of about 30 nm which is considerably larger than 13 nm of a nanocrystalline Fe
73.5
Si
15.5
B
7.0
Cu
1.0
Nb
3.0
alloy and, thus, further research to decrease the coercivity with a high heating rate annealing is needed.