Oscillatory antiferromagnetic interlayer exchange coupling in Co_2Fe(Alo.5Sio.5)/Ag/Co_2Fe(Alo.5Sio.5) films and its application to trilayer magnetoresistive sensor

摘要

We report oscillatory antiferromagnetic (AFM) interlayer exchange.coupling (IEC) in a trilayer film with Co_2Fe(Al_(0.5)Si_(0.5)) (CFAS) Heusler alloy ferromagnetic layers and a Ag spacer layer. The AFM-IEC was observed only in the films annealed at >400℃, suggesting the enhancement of the interfacial spin-dependent scattering by improved B2 order in the CFAS film is its origin. Using the AFM coupled trilayer, we demonstrated a scissors-type trilayer CPP-GMR device with relatively large ARA of 4.5 mΩ μm~2 and MR ratio of 24%.