Magnetic interface coupling between ultrathin Co and NixMn100-x films on Cu(001)

Growth and magnetic properties of NixMn100-x single and Co/NixMn100-x bilayer films on Cu(001) have been investigated by grazing ion scattering, Auger electron spectroscopy, low-energy electron diffraction, and magneto-optical Kerr effect. The increase in the coercivity field strength and the decrease in the signal strength of the hysteresis loop is used as a measure of the magnetic interface coupling in the bilayers. The strength of the antiferromagnetic/ferromagnetic interface coupling rapidly increases with increasing NiMn thickness. Above a critical NiMn thickness of about 8 ML, we observe the strongest interface coupling effects in the intermediate concentration regime with a Ni content 10 <= x <= 40 at a temperature of T=300 K and 5 <= x <= 50 for T=133 K.