INFLUENCE OF THE NONMAGNETIC METAL SPACER ON THE MAGNETIC PROPERTIES AND MICROSTRUCTURE OF THE MULTILAYER FILMS

Ta / NiFe/ Bi (Ag, Cu)/ FeMn /Ta and Ta / NiFeI /FeMn / Bi(Ag, Cu)/ NiFeII / Ta films were prepared by magnetic sputtering. The texture and the dependences of the exchange-coupling field on the thickness of Bi, Ag, and Cu in Ta / NiFe/ Bi(Ag, Cu) /FeMn /Ta and Ta/ NiFeI / FeMn / Bi(Ag, Cu)/ NiFeII / Ta films were studied. XPS results indicate that the Bi atoms migrated into the FeMn layer during the deposition process and a FeMnBi alloy was probably formed or the Bi atoms existed as an impurity in the FeMn layer in Ta / NiFe / Bi(Ag, Cu)/ FeMn / Ta. Otherwise, in Ta / NiFeI / FeMn / Bi(Ag, Cu) / NiFeII / Ta films, Bi, Ag, and Cu atoms do not remain entirely at the interface of the FeMn / NiFeII film, but at least partly segregate to the surface of the NiFe film.