Magnetomechanical properties and anisotropy compensation in quaternary rare earth-iron materials of the type Tb/sub x/Dy/sub y/Ho/sub z/Fe/sub 2/

The static and dynamic magnetomechanical properties, in the temperature range -60/spl deg/C to +100/spl deg/C, of quaternary compositions of the type Tb/sub x/Dy/sub y/Ho/sub z/Fe/sub 2/ (x+y+z=1) which have K/sub 1/ close to zero at +20/spl deg/C are presented. The maximum room temperature values of d/sub 33/ (7.9 nm A/sup -1/) and k/sub 33/(0.62) are achieved for Tb/sub 0.20/Dy/sub 0.22/Ho/sub 0.58/Fe/sub 2/, the composition for which K/sub 2/ is also close to zero at +20/spl deg/C. Calculations performed with an anisotropy model including an eighth-order term show a 20 fold decrease in the anisotropy of Tb/sub 0.20/Dy/sub 0.22/Ho/sub 0.58/Fe/sub 2/ in comparison with Terfenol-D. This decrease is not as effective in improving material performance as the opposing influence of the reduction in saturation magnetostriction.