Magnetoelastic coupling and ΔE effect in TbxDy1−x single crystals

Abstract

The elastic moduli of the highly magnetostrictive TbxDy1−x alloys (x=0.5, 0.6, and 0.67) were measured at 77 K under conditions of constant magnetic field and constant magnetic induction. From these values the magnetic contribution to the moduli (intrinsic ΔE effect) and magnetoelastic coupling factor k were calculated. For Young’s moduli measured under constant flux density (magnetically blocked conditions), it was found that EB∼20 to 50 GPa. For measurements made while maintaining a constant magnetic field (magnetically free conditions), it was found that Young’s moduli EH minima range from ∼3 to 5 GPa. Such large differences between EB and EH yield magnetoelastic coupling factors in excess of 0.9. Theoretical expressions of the magnetic contribution to the elastic compliance, (1/EH−1/EB), were derived using the single vector magnetization rotation model.

Stress and magnetic field-dependent Young's modulus in single crystal iron–gallium alloys

“…Even if a small bias field is present, it is possible to maintain a constant B, while domains with 01 and 1801 orientations simultaneously rotate to 901 producing magnetoelastic strain without necessarily changing the net magnetic induction. As expected from the theory, both E H and E B were shown [29][30][31] to vary in rare-earth compounds based on the stress and magnetization states of the material.…”

“…Another quantity of interest studied by several researchers [29][30][31] is the Young's modulus at constant magnetic induction (E B ). This quantity can be measured from the stress-strain curve of a material provided the magnetic induction is kept constant throughout the stress cycle by appropriately adjusting the magnetic field.…”

Surface-acoustic-wave-driven ferromagnetic resonance in (Ga,Mn)(As,P) epilayers

“…Microscopically, the processes at play are generally the rotation of magnetization, often involving the rearrangement of magnetic domains. Although it is most often mentioned in static measurements [29], Ganguly et al [23] had already identified the dynamic E effect nature of the field-dependent velocity variations induced by a SAW on nickel. They had, however, demonstrated that it was a nonresonant effect.…”

Dynamic magnetomechanical properties of epoxy-bonded (Tb0.3Dy0.7)1–xPrxFe1.55 (0≤x≤0.4) pseudo-1–3 magnetostrictive composites

“…Although Terfenol-D has been successfully employed in sonar and actuator devices, operation of Terfenol-D above a few kilohertz is limited by the presence of eddy-current losses [3][4][5]. Another problem associated with Terfenol-D is brittleness, which causes difficulties in machining and device fabrication [3,6]. In the past decade, much research effort has been devoted to the study of epoxybonded Terfenol-D composites [7][8][9][10][11].…”