Among metal additives M(M:Pt, Pd, Rh, Ir, and Cu) of antiferromagneticCrMnMxfilms, Pd was the most suitable M for obtaining large exchange coupling. For the 50 nmCrMnPd5/40 nmNi81Fe19films, the exchange coupling field of∼28 Oeand the blocking temperature of∼380 °Ccould be obtained. TheCrMn(Pt, Pd, or Rh)xfilms having the optimum content of∼8,∼5,or∼11at.&percent; exhibited the same high blocking temperature. The high blocking temperature of theCrMnPt8,CrMnPd5,andCrMnRh11films 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. ©1997 American Institute of Physics.