Magnetic anisotropy of epitaxial Cu/Ni/Cu nanolines

Abstract

Continuous nickel films grown pseudoepitaxially between copper layers have been shown to have strong perpendicular magnetic anisotropy due to large magnetoelastic and interface magnetocrystalline anisotropy energies. These Cu/Ni/Cu films with tNi=6.9 nm have been patterned into lines approximately 200 nm wide using interferometric lithography and ion milling. Torque magnetometer measurements show the anisotropy of the nanolines to be significantly different from that of the continuous films. The magnetoelastic anisotropy (favoring perpendicular magnetization) decreases in the patterned films due to strain relaxation at the line edges. Although the anisotropy change for this line width is most likely due to shape anisotropy, we anticipate observation of magnetoelastic anisotropy due to strain relief at the edges of the lines at narrower line widths in future work.