UC Berkeley

Py/FeMn/Cu(001) and Py/FeMn/Ni/Cu(001) films were grown and studied as a function of both the FeMn and the Ni thicknesses using rotating magneto-optic Kerr effect and x-ray magnetic circular dichroism. For Py/FeMn/Cu(001), we find that the FeMn antiferromagnetic order switches the sign of the Py fourfold magnetic anisotropy but has little effect on the step-induced uniaxial magnetic anisotropy. For Py/FeMn/Ni/Cu(001), we find that out-of-plane Ni magnetization has little effect on the Py magnetic anisotropy, but in-plane Ni magnetization enhances the Py magnetic anisotropy in the region just above antiferromagnetic transition thickness. The underlying mechanism could be attributed to the FeMn 3Q spin structure. © 2013 American Physical Society.