Directionality of Magnetic Properties in Fe-Co Alloys.

摘要

A program was written to analyze the data following the general outline of Nye's analysis of anisotropic properties but adapted to the symmetries appropriate to magnetostriction in cubic materials such as the bcc Fe-Co alloy under study. The results of the analysis revealed, however, that the calculated coefficients of the magnetostriction tensor were too small and exhibited large errors. Moreover, the field strengths applied were only a few Gauss, after accounting for demagnetization effects, whereas the field strength required to saturate the magnetostriction strain is of the order of one hundred Gauss, far above the capabilities of the apparatus available to the project at the time. Our conclusion was, therefore, that a new approach will be required in order to perform the experiment as originally designed. The challenge will be to find a way to apply high magnetic fields in a conformation that permits the laser illumination to be reflected off the sample surface at angles far from normal incidence.