Micromagnetics of magnetic chemical modulations in soft-magnetic cylindrical nanowires

<p>Abstract:</p> <p>We analyze the micromagnetics of short longitudinal modulations of a high magnetization material in cylindrical nanowires made of a soft-magnetic material of lower magnetization such as Permalloy, combining magnetic microscopy, analytical modeling and micromagnetic simulations. The mismatch of magnetization induces curling of magnetization around the axis in the modulations, in an attempt to screen the interfacial magnetic charges. The curling angle increases with modulation length, until a plateau is reached with nearly full charge screening for a specific length scale, larger than the dipolar exchange length of any of the two materials. The curling circulation can be switched by the &OElig;rsted field arising from a charge current with typical magnitude 10¹²A/m².</p>