Tuning Perpendicular Anisotropy Gradient in Co/Pd Multilayers by Ion   Irradiation
  The tunability of Ar+ ion irradiation of Co/Pd multilayers has been employed to create depth-dependent perpendicular anisotropy gradients. By adjusting the Ar+ kinetic energy and fluence, the depth and lateral density of the local structural modification are controlled. First-order reversal curve analysis through X-ray magnetic circular dichroism and conventional magnetometry studies show that the local structural damage weakens the perpendicular anisotropy near the surface, leading to a magnetization tilting towards the in-plane direction. The ion irradiation method is complementary to, and may be used in conjunction with, other synthesis approaches to maximize the anisotropy gradient. 
Peter K. Greene, Julia Osten, Kilian Lenz, Jurgen Fassbender,   Catherine Jenkins, Elke Arenholz, Tamio Endo, Nobuyuki Iwata...
cond-mat.mtrl-sci