Magnetic Properties of Ni/Cu/Ni Epitaxial Films with Perpendicular Anisotropy

The effective magnetic anisotropy K-eff has been studied at room temperature in Cu/Ni/Cu/Ni/Cu(001) epitaxial films with perpendicular magnetization as a function of the interleaving Cu block thickness t(Cu) ranging from 0 nm to 6 nm and being the Ni blocks 3 nm thick. We have found that the value of K-eff decreases when comparing the structures with t(Cu) = 0 and 0.2 nm, although the strain increases. For larger values of t(Cu), K-eff increases, although above t(Cu) = 1.8 nm, K-eff is nearly independent of t(Cu). These results can be explained using the measured in-plane strain epsilon and a surface anisotropy constant, K-s = -0.4 mJ/m(2).http://iopscience.iop.org/article/10.1088/1742-6596/200/7/072019