The .cofe / Crpt Bilayers Exchange Bias System

Exchange coupling between an antiferromagnet(AFM) and a ferromagnet(FM) across their common interface, due to its intriguing physics and the key role in giant magnetoresistance effect spintronic devices, has attracted a great deal of attention in recent years. In this dissertation, we studied on the exchange bias effect of CoFe/CrPt.The CoFe/CrPt films were prepared by using DC magnetron sputtering, the Cr and Pt was sputtered all together. As deposited, CoFe/CrPt layers exhibit no exchange bias. After being annealed at 350℃ for 5 hours in a vacuum, the CrPt stack has been transformed into uniform CrPt alloy film with L1₀ phase, which pins the adjacent CoFe layer with a pinning field of 20 Oe .We have studied on antiferromagnetic L1₀ CrPt film as a pinning layer. We found that when anMn layer is inserted between the Co_0.9Fe_0.1 film and CrPt layer, the exchange bias of the CoFe/CrPt film is enlarged sixflod reaching ～150Oe at room temperature. And for an equal pinning field, the thickness of AFM of the film with interfacial Mn addition is little. Meanwhile, the exchange bias is also depend on L1₀ CrPt and an adequate AFM thickness.Lastly, in the CoFe/CrPt system, we found that adding Mn into CrPt film by inserting thin Mn layers an optimum pinning field of ～60Oe can be obtained.