Magnetostrictive Body Centered Iron Base Alloys

University Of Maryland, College Park, College Park MD

Investigators

Abstract

0095166 Wuttig A thermodynamical model of defects in crystalline solids which includes a novel field induced defect property tensor accounts for the known variation of the excess magnetostriction in Fe-Al and Fe-Ga alloys. Specifically, the model suggests that next nearest neighbor substitutional- substitutional pairs of tetragonal symmetry are responsible for the effect. The studies are directed to determine the model parameters self-consistently through measurements of the relaxed and unrelaxed magnetostrictive, elastic and magnetic anisotropy constants as well as lattice constants. In an effort to generalize the model the studies will be extended to Fe-C-Al and Fe-C-Ga and possibly additional alloys containing defect pairs of tetragonal symmetry. The studies will lead to a basic understanding of the significant magnetostriction in body-centered iron-base alloys. They will at minimum systematize the excess magnetostriction and maximally establish criteria for the development of novel alloys with a significant magnetostriction. %%% Materials with a magnetostriction as large as .000200 are of significant technological interest. The studies will identify the nature of the magnetostriction in body centered cubic iron base alloys and establish criteria for the search of additional magnetostrictive alloys. ***