Tailoring Domain-Wall Dynamics With Uniaxial Anisotropy in Nanowires

Micromagnetic modeling is used to show that faster domain walls and higher Walker breakdown fields are achieved using materials with an in-plane uniaxial anisotropy weaker than the shape anisotropy. The domain-wall velocity increases by more than 30% if the uniaxial anisotropy direction changes from the long axis to the short axis of the wire. The superposition of uniaxial and shape anisotropies can be interpreted as a change in the effective wire width. Nonuniform uniaxial anisotropy is averaged over the wire thickness, suggesting that the domain-wall dynamics can be tailored by controlling the material anisotropy during fabrication.