Magnetic Properties of Compositionally Modulated Fe/(Al,Ta,Ti,Ag,Cu) Films

The structural and magnetic properties of Fe/ (Al, Ta, Ti, Ag, Cu) compositionally modulated binary multilayer films prepared by double-target dc magnetron sputtering were investigated. In all films, both Fe and nonmagnetic metal layers were crystallized and the Fe layer had a (111) preferred orientation, independent of the kind of nonmagnetic metal. The α-Fe (110) interplanar spacing depends on the nonmagnetic metal used. Large lattice strain exists in Fe/Ti and Fe/Ta multilayer films, while there is little lattice strain in Fe/Al, Fe/Cu and Fe/Ag multilayer films. The coercivity H_c of multilayer films decreases with increasing Fe layer thickness. The value of H_c depends on the nonmagnetic metal; the minimum value of H_c=0.25 Oe was observed in Fe/Ag multilayer films, the Fe layers of which had the smallest lattice strain.