Enhancement of the Magneto-Mechanical Properties in Directional Solidified Fe80Al20 Alloys by Doping Tb

Enhancement of the magneto-mechanical properties in directional solidified Fe80Al20 alloys by doping Tb is demonstrated. The Delta E effect of 9.1%, large magnetostriction of 144 ppm, magnetostriction sensitivity of 0.28 ppm/Oe, Delta G effect of 5.4%, and magneto-mechanical coupling of 29.74% reached for Fe79.9Al20Tb0.1 alloy are beneficial for applications. The increased magnetostriction with increasing the Tb content x from 0 to 0.1 is related to the increased degree of (110) texture with Tb doping. Notably, the increased magnetostriction sensitivity, resulted from the increased magnetostriction with Tb-doping, leads to the enhancement of Delta E and Delta G effects. Nevertheless, the degraded (110) texture for higher Tb content (x = 0.15) results in the reduction of magneto-mechanical properties. Summarized with the experimental measured and theoretically estimated results, the micro eddy-current mechanism mainly governs the change of damping capacity with H for frequency of vibrations similar to 2.0 kHz resulting from the magnetic domain wall motion. Moreover, the amplitude and temperature dependences of internal friction and elastic modulus data, measured by DMA, including damping capacity and Young's modulus, at a frequency of 0.1-30 Hz could characterize hysteretic damping and anelastic effects at heating. The result of this study suggests a cost-effective and simple method to obtain Fe80Al20 based alloy with excellent magneto-mechanical properties via proper Tb-doping. (C) 2021 Elsevier B.V. All rights reserved.