Abstract
(001)-oriented FePt graded media are obtained by using PtMn underlayers. The PtMn underlayer not only behaves as the (001) structural template but provides the diffusion source of Mn. The diffusion of Mn into FePt reduces its anisotropy but, on the other hand, the exchange coupling between antiferromagnetic PtMn and ferromagnetic FePt enhances the anisotropy. Hysteresis loops taken from x-ray magnetic circular dichroism confirm the competition between these two effects, leading to the lowest anisotropy in the middle of FePt. © 2011 American Institute of Physics.