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Magnetoelasticity encompasses a wide range of phenomenons, including volume and Joule magnetostriction, the Villari effect, the direct and inverse Wiedemann effects, the Matteuci effect, the ÎE effect, a magnetoelastic contribution to the apparent magnetic anisotropy, and others. These effects are conveniently codified in a magnetoelastic energy density which, together with the magnetic (including exchange) and elastic energy densities, provides a consistent thermodynamic description of magnetoelasticity. Each of these effects and the corresponding terms of the energy density are reviewed here. This energy density is described by a collection of material constants that, in principle, are derivable from theory. The physical coordinates that are kept constant in any experiment dictate the relevant combination of these material constants that is ultimately observed. Static and dynamic measurements are generally carried out with different constraints, and, not surprisingly, these experiments measure different combinations of material parameters. For example, the highly magnetostrictive smart material Terfenol-D (Dy0.73Tb0.27Fe1.95) has a static magnetic anisotropy that is markedly different from the anisotropy exhibited in a dynamic measurement.
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