Dipolar interactions in arrays of nickel nanowires studied by ferromagnetic resonance - art. no. 104415

Using a planar microstrip transmission line, the dipolar interactions in el ectrodeposited Ni nanowires arrays an characterized as a function of the me mbrane porosity (4% to 38%) and the wire diameter (56 to 250 nm). The dipol ar interactions between the wires can be modeled in a mean-field approach a s an effective uniaxial anisotropy field oriented perpendicular to the wire axis and proportional to the membrane porosity. The dipolar interaction fi eld opposes the self-demagnetization field of an isolated single wire which keeps the magnetization parallel to the wire axis. An increase in the poro sity therefore induces a switching of the effective anisotropy easy axis fr om parallel to perpendicular to the win axis above a critical porosity of 3 5-38% independent of the wire diameter.