Magnetomechanical properties of single crystal Terfenol-D

Quasi-static and dynamic magnetomechanical measurements have been made on a twin-free <111> oriented single crystal of Tb/sub 0.27/Dy/sub 0.73/Fe/sub 2/ (Terfenol-D). Unusually large values of dynamic strain coefficient, d/sub 33/, and magnetomechanical coupling coefficient, k/sub 33/, of 19.1 nm A/sup -1/ and 0.83 respectively were recorded with an oscillating field of amplitude 500 A m/sup -1/ rms at room temperature. The static magnetostriction saturated at 1688/spl times/10/sup -6/, however 90% of this strain was achieved with a field of 45 kA m/sup -1/. The strain versus magnetization curves exhibit unusually linear regions, allowing confirmation that 71/spl deg/ domain wall motion is primarily responsible for the high coupling coefficient of this material.