Fabrication and magnetoresistive properties of magnetron-sputtered CoFe/Cu spin valves with antiferromagnetic IrMn pinning

Nanolayered ferromagnetic/non-magnetic structures exhibit the giant magnetoresistance (GMR) effect and are used in a variety of applications. Spin valves are one class of devices that fall into the GMR category. In this work, the fabrication and characterization results of magnetron sputtered Ta/IrMn/CoFe/Cu/CoFe/Ta spin valve structures are presented. Two groups of samples were produced where the thickness of the Cu spacer layer or the CoFe pinned layer were varied in search of the highest magnetoresistance value. The maximum value of 4.8% magnetoresistance was obtained for a sample with the composition of Ta(5 nm) / IrMn(15 nm) / CoFe(2 nm) / Cu(2 nm) /CoFe(5 nm) / Ta(5 nm) when the sample was shaped into a meandering channel with 2 μm width. The achieved results are promising and will be used to further develop spin valve technology for various applications.