Magnetomechanical coupling factor (k₃₃) of (110) oriented Tb_0.36Dy_0.64 (Fe_0.85Co_0.15)₂ alloys

Near (110) oriented Tb_0.36Dy_0.64 (Fe_0.85Co_0.15)₂ alloys were prepared by zone melting directional solidification method. The magnetomechanical coupling factor (k₃₃) was determined by resonance/anti-resonance method in low bias fields. It was found that k₃₃ is sensitive to both the bias field and the compressive pre-stress. Under no compressive pre-stress, an optimum k₃₃ equal to 0.513 can be obtained at a bias field of 50.9 kA/m. While under applying a compressive pre-stress of 10 MPa, the k₃₃ will be lowered due to the pre-stress induced increase of 71° domain wall energy, which hinders the movement of magnetic moments or domain walls, resulting in the decrease of the transition efficiency between the magnetic and mechanical energies.