Microstructure and magnetic properties of Tb-Dy-Fe1.9

Materials of the composition Tb_xDy_1-xFe_1.9 (x=0.27, 0.3, and 0.5), have been prepared by a contained float-zone growth technique. These materials have been found to exhibit magnetostrictive strains greater than 1000 microstrain with magnetomechanical coupling coefficients on the order of 0.6. Microstructural investigations have highlighted the complex relationship between the magnetic domain structure and the inherent defect structure of the materials. All alloys were prepared using sublimed-quality rare earth metals and spec-pure iron. Microstructure observations were carried out using both optical and electron microscopes. The strain measurements were made using conventional techniques. The measurement of the magnetomechanical coupling coefficient (k₃₃) was carried out using a resonance method.