Giant magneto striction of exchange-coupled (TbFe/Fe) ML with high sensitivity after heat treatment

The possibility to improve the magnetoelastic (MIE) properties of exchange- coupled (TbFe/Fe) multilayers NIL after a post-deposition annealing treatme nt is presented. Giant magnetostriction (GMS) improvement has been observed in highly anisotropic single domain state (SDS) multilayers deposited by i on sputtering under a magnetic polarization field H-d from two points of vi ews corresponding to strong increase of both the magnetoelastic constant b( gamma ,2) by about 75% and the GMS sensitivity db(f)/dH, by a factor 6 wher e b(f) is the NM parameter of the flexural motion of the (TbFe/Fe) x 40/gla ss bimorph. These improvements have been induced for both the flexion and t he torsion motions of the bimorphs submitted to either a static or a dynami cal magnetic field which can excite linear and nonlinear anharmonic oscilla ting modes.