Giant magnetostriction in TbFe/FeCo multilayers

In order to build magnetostrictive microactuators and -sensors thin film materials are needed which combine high magnetostriction at low external magnetic fields with low coercivity. In this paper a multilayer material consisting of giant magnetostrictive alloy layers (TbFe) and layers with a high magnetization material (FeCo) is presented which exhibits a saturation magnetoelastic coupling coefficient of 28 MPa at 20 mT external field and has a coercive field of 2 mT. It is shown that this artificially layered material behaves like an uniform material which can be engineered by varying the layer thickness ratio and the annealing conditions.