Quasi-static and dynamic magnetomechemical measurements have been made on a
twin-free <111> oriented single crystal of Tb0.27Dy0.73Fe2 (Terfenol-D). U
nusually large values of dynamic strain coefficient, d(33), and magnetomech
anical coupling coefficient, k(33), of 19.1 nm A(-1) and 0.83 respectively
were recorded with an oscillating field of amplitude 500 A m(-1) rms at roo
m temperature. The static magnetostriction saturated at 1688 x 10(-6), howe
ver 90% of this strain was achieved with field of 45 kA m(-1). The strain v
ersus magnetization curves exhibit unusually linear regions, allowing confi
rmation that 71 degrees domain wall motion is primarily responsible for the
high coupling coefficient of this material.