MAGNETOELASTIC EFFECTS IN RARE-EARTH IRON-ALUMINUM COMPOUNDS

Magnetic and magnetoelastic measurements under various conditions of compressive stress and applied field have been carried out on samples with the composition Tb0.3DY0.7(Fe1-xAlx)1.95, 0 less-than-or-equal-to x less-than-or-equal-to 0.1, prepared by a float-zone growth technique. Their magnetoelastic performances compare favorably with the highly magnetostrictive ''Terfenol-D'' compounds by having large magnetostrictive strains (lambda approximately 1200 ppm at approximately 120 kA/m), good magnetomechanical coupling (k33 almost-equal-to 62 %) and a large strain coefficient (d33 almost-equal-to 80 nm/A). The substitution of aluminum for iron produces a material with potential benefits for use in actuators: higher electrical resistivity and improved ductility, which reduce eddy current effects and increase the mechanical strength.