Cylindrical domains in small ferromagnetic spheres with cubic anisotropy

Abstract

Magnetization configurations are computed for small ferromagnetic spheres with cubic anisotropy. A cylindrically symmetrical configuration is found, which has a lower energy than a single domain, for a sphere radius larger than about 27.7 nm, for cubic cobalt. In magnetite, the changeover from a single domain to the cylindrical configuration is at a radius of about 27.0 nm. This problem has been studied particularly for cubic iron oxides, used in magnetic recording.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>