Perpendicular magnetic anisotropy and strain in Ni/Cu/Ni60Cu40/Cu(001)

We report that for epitaxial Cu/Ni60Cu40/CU(001) and for Cu/Ni/Cu(001) stru ctures, the in-plane lattice parameter (a(in)) for Cu increases with increa sing Cu overlayer thickness. For the Cu/Ni(30 Angstrom)/Cu/Ni/Cu(001) struc tures, the value of a(jn) of the 30-Angstrom Ni film directly depends on a( in) of the Cu underlayer. Magneto-optic Kerr effect measurements on a CU/Ni /Cu/Ni60Cu40(001) structure reveal an increase in the magnetoelastic anisot ropy with increasing Cu spacer layer thickness and, surprisingly, suggest n o significant difference between the interface anisotropy of the Ni-Cu and the Ni-Ni60Cu40 interface. The stronger perpendicular magnetic anisotropy f or Cu/Ni/Cu(001) structures compared to Cu/Ni/Ni60Cu40/Cu(001) is therefore attributed to an increased magnetoelastic anisotropy contribution.