Antiferromagnet/ferromagnet interface roughness effect on exchange coupling and MR ratio in spin-valve system

Summary form only given. Antiferromagnetic materials such as NiMn, PtMn, IrMn, FeMn, NiO etc. have been used as an exchange layer in spin-valve devices "GMR/TMR" to provide the pinning field between the exchange layer and the pinned layer. The authors have studied the effect of IrMn roughness on the exchange coupling with CoFe in the simple bottom spin-valve structure: Ta/IrMn/CoFe/Cu/CoFe/Ta. The IrMn roughness can be varied by changing the process pressure during deposition, and was measured using atomic force microscopy. A VSM with MR probe also used to measure the MR ratio and exchange coupling.