Giant magnetostrictive TbFe/Fe multilayers

Magnetostrictive multilayer films which combine exchange coupled amorphous giant magnetostrictive materials (Tb0.4Fe0.6) and materials with large magnetic polarizations (Fe) were prepared by de or rf magnetron sputtering using rotary turn-table technique in a stop-and-go mode. The structural, elastic, magnetic and magnetostrictive properties of Tb0.4Fe0.6(4.5 nm)/Fe(x nm) multilayers were investigated in relation to the Fe layer thickness and the stress annealing temperature. Giant magnetoelastic coupling coefficients (or magnetostrictions) are achieved at low fields, due to the magnetic polarization enhancement in such multilayers. Saturation magnetoelastic coupling coefficients of about 20 MPa at 20 mT can be achieved. Therefore such composite materials should be much more appropriate for low-field applications than the simple homogeneous alloy films studied up to now. (C) 1997 Elsevier Science S.A. (C) 1997 Elsevier Science S.A.