Significant enhancement of ΔE effect in Fe87Ga13 alloy by doping 0.2 at% Dy

Abstract

We present the effects of Dy additives on the ΔE and ΔG effects, magnetic properties, magnetostriction sensivity, magneto-mechanical coupling, and phase constitutions of Fe87Ga13Dyx alloys, prepared by vacuum induction-melting and then water-quenching. ΔE and ΔG effects, permeability (μR), dλ///dH, and magneto-mechanical coupling (K) are significantly enhanced by doping 0.2 at% Dy. The attractive ΔE/E0 of 5% at very small H = 0.10 kOe and a significant enhancement of about 100% from 6.1% to 12.0% in ΔE/E0 at H = 2.5 kOe (ΔEs/E0) achieved for Fe86.8Ga13Dy0.2 alloy favors for applications. The enhanced μR indicates magnetic softening. The increased amount of modified D03 phase and magnetic softening contribute to remarkable enhancements in dλ///dH, accordingly ΔE and ΔG effects, and K. Nevertheless, higher Dy content (x = 2.0) reduces the amount of modified D03 phase, μR, dλ///dH, and therefore K, ΔE, and ΔG effects. The proportional relation between ΔEs/E0 and K2 suggests that the experimentally ΔEs/E0 is consistent with theoretically calculated K2. This work provides an effective method for significantly enhancing the ΔE and ΔG effects and magnetostriction sensitivity for Galfenol alloys.