Effect of Pt spacers on interface exchange coupling in ferromagnetic/antiferromagnetic bilayers

Abstract

By inserting a Pt spacer between ferromagnetic (FM)/antiferromagnetic (FeMn) coumpling systems or by doping Pt element in the AFM layer, the depth dependence of Pt spacer and the thickness dependence of Pt doping layer on exchange bias (Hex) and coercivity (Hc) are investigated. The results indicate that the number of uncompensated spin moments (UCSs) of NiFe/FeMn(dPt)/Pt/FeMn increases as a result of inserting Pt spacer, which enhances Hex and Hc of the system. Also, the distribution depth about 1.3 nm of UCS of FeMn in NiFe/FeMn system is inferred. Besides, by doping Pt element in FeMn near the FM/FeMn interlayer, we find that the Hex of the system is enhanced efficiently, which is caused by the huge increase of the number of UCSs in the system.