Co2MnGe-based current-perpendicular-to-the-plane giant-magnetoresistance spin-valve sensors for recording head applications

Magnetic and magnetotransport properties of current-perpendicular-to-the-plane (CPP) giant-magnetoresistance (GMR) spin-valve sensors containing the Heusler alloy Co2MnGe are presented. The geometrical and head integration constraints which exist for recording head applications are discussed and dictate various design compromises which determine the final device properties. Here we show that even for small total sensor thicknesses 400 angstrom and anneal temperatures < 250 degrees C we can obtain CPP-GMR signal levels up to Delta RA = 4 m Omega-mu m(2) at room temperature when inserting Co2MnGe in both the free layer and reference layers of the spin valve. Output levels increase to 10 m Omega-mu m(2) when reducing the temperature below 100 K, demonstrating the strong temperature dependence of the spin-dependent scattering in the Co2MnGe-based magnetic layers. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3563578]