Giant magnetostrictive multilayers for thin film actuators

Magnetostrictive multilayers which combine giant magnetostrictive layers (amorphous Tb_0.4Fe_0.6) and layers with large magnetic polarizations (Fe or Fe_0.5Co_0.5) were prepared by magnetron sputtering. Giant magnetoelastic coupling coefficients (28 MPa at 20 mT in the case of TbFe/FeCo) are achieved at low fields, due to the magnetic polarization enhancement in such multilayers. The high magnetostriction at low-fields and the possibility to engineer the material´s properties by layer thickness variation are considered to be important features for using these films as thin film actuators, e.g. in micropumps or micromotors