Transverse magnetization due to shearing stress on amorphous ferromagnetic materials

It is shown that a shearing stress σ applied to an amorphous ferromagnetic sample magnetized along a longitudinal direction x, gives rise to a transverse magnetization component M
y
. A square sheet (25 × 25 mm
²
) of Metglas 2826 (Fe
40
Ni
40
P
14
B
6
) was clamped so as to apply a shear stress, while the material was magnetized by a field H
x
parallel to the clamps. The M
x
component is almost unaffected by the stress, while a transverse component M
y
appears, which depends on H
x
and σ. At constant stress M
y
increases with H
x
up to a maximum, which reaches about 15% of the saturation M
s
for
\sigma \cong 1.5
kg/mm
²
. By minimizing the sum of magnetostatic and magnetoelastic energies, M
y
can be calculated as a function of H
x
, σ and λ, the magnetostrictive relative elongation, determined by conventional methods. A good fit is found between the M
y
vs. H
x
experimental and calculated curves, limited to the high field region. Alternatively, the M
y
measurements can be used to calculate λ as a function of H
x
. Values of λ vs. H
x
consistent for most of the measured curves are found in this way, which agree with the 11.5 × 10
^-6
saturation value, but deviate from low fields data obtained with conventional magnetostriction measurements. This discrepancy is probably due to the different stress conditions under which λ's are calculated or directly measured, or to some distribution of magnetoelastic anisotropy due to frozen-in stresses.