Abstract:
Metallic glass ribbons ofNi-Fe-B alloys are prepared by melt spinning technique.
with composition Nigo_xFexBlowhere x=20,30,40 and 50. The thicknesses of the samples
were 22f.Lm,20f.Lm,23f.Lmand 19f.Lmrespectively. The amorphousity of the samples has
been checked by X-ray diffraction technique. Magnetostriction of these ribbons has been
measured by resistance strain gauge technique at room temperature as a function of field
and composition. The linear saturation magnetostriction of the ribbons has been
determined by rotating the magnetization vector from perpendicular position to parallel
position of the magnetization direction with respect to the direction of strain
measurement. It is assumed that the direction of the field and the direction of
magnetization practically coincides, specially for the maximum field. The direction of
measurement of strain is determined from the direction of the bonded strain gauge. The
magnetostrictive in amorphous alloys originate from the magneto elastic interaction
associated with the local anisotropies and the local strain controlling the local direction
of the magnetic moments. The saturation magneto stricti on decreases as Ni-concentration
increases. The magnetoelastic energy and hence magnetostriction depends on the
electrons located at the Fermi level of the alloy and is proportional to the spin-orbit
energy shift at the Fermi-level. However, the observed magnetostriction has been
discussed in terms of the pair model with random local axis because of the simplicity of
the model. The results are interpreted in terms of domain motion and domain rotation
which are spontaneously strained.
Hall resistivity of amorphous Ni-Fe-B ribbons has been measured as a function
Of field and change of composition. The field was varied from 0 to 4.16 KG and the
composition of the ribbons was varied from 20% to 50% Fe ke,~ping the boron -
concentration of 20% as constant. In the range of the field available Hall resistivity
increases for all the compositions with increasing field, because the saturation field
needed for attaining the maximum Hall resistivity could not be reached. The results are
explained by the conventional theory.
