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_0.27Dy_0.73Fe₂ (Terfenol-D). Unusually large values of dynamic strain coefficient, d₃₃, and magnetomechanical coupling coefficient, k₃₃, of 19.1 nm A^-1 and 0.83 respectively were recorded with an oscillating field of amplitude 500 A m^-1 rms at room temperature. The static magnetostriction saturated at 1688×10^-6, however 90% of this strain was achieved with a field of 45 kA m^-1. The strain versus magnetization curves exhibit unusually linear regions, allowing confirmation that 71° domain wall motion is primarily responsible for the high coupling coefficient of this material