Interpretation of the magnetization mechanism in Terfenol-D using Barkhausen pulse-height analysis and irreversible magnetostriction

The ternary alloy Dy0.7Tb0.3Fe1.9, known as Terfenol‐D, is a highly magnetostrictive alloy with magnetostriction coefficients along the principal crystallographic directions of λ111=1640×10−6 and λ100≤100(±30)×10−6. The bulk magnetostriction λ is dependent on the state of magnetization M, on the original domain configuration, and on the texture of the material. This paper reports on Barkhausen measurements and magnetostriction. The pulse‐height distribution of Barkhausen emissions revealed events occurring at a specific amplitude which were stress dependent. The magnetostriction results gave a saturation magnetostriction in excess of 2000 μ strain.