Study of crystallographic and magnetic texture in soft magnetic materials by the measurement of galvanomagnetic properties

Abstract

Longitudinal and transverse magnetoresistivity measurements have been performed on textured samples of Ni, Ni-Cu and Ni-Fe alloys, at different temperatures and in fields up to 10 KOe. All the alloy samples, with the exception of 28.32 at. % copper alloy, exhibit marked anisotropy in the polar plots of transverse magnetoresistivity characteristic of pure nickel whereas 28.32 at. % Cu alloy shows an isotropic behaviour. Both spin-orbit and domain theories, though capable of explaining partly the anisotropies observed in transverse magnetoresistivity at H = 7.75 KOe, fail to account for the observed anisotropies at H = 1.55 KOe. These anisotropies as well as the field dependence data taken along various directions of the polar plot lend themselves to a straightforward explanation in the light of a transport theory modified slightly to include shape anisotropy. The angles, characterizing the magnetic texture in the samples of present interest, are evaluated from a general theory utilising the present experimental data and lend a firm support to the theory propounded for the influence of crystallographic texture on the galvanomagnetic properties.