Effect of metallic additives (M) on the exchange coupling of antiferromagnetic CrMnMx films to a ferromagnetic Ni81Fe19 film

Abstract

Among metal additives M(M:Pt, Pd, Rh, Ir, and Cu) of antiferromagnetic CrMnMx films, Pd was the most suitable M for obtaining large exchange coupling. For the 50 nm CrMnPd5/40 nm Ni81Fe19 films, the exchange coupling field of ∼28 Oe and the blocking temperature of ∼380 °C could be obtained. The CrMn(Pt, Pd, or Rh)x films having the optimum content of ∼8, ∼5, or ∼11 at.% exhibited the same high blocking temperature. The high blocking temperature of the CrMnPt8, CrMnPd5, and CrMnRh11 films was attributed to the nearest neighbor Mn–Mn within the respective films being at the same distance as that at which the Mn–Mn exchange integral showed the maximum negative value.