  Magnetization of soft-ferromagnetic nano- and microtubes of nanometer-thin
walls (a single-widening rolled-up nanomembranes) is theoretically studied
using analytical and numerical approaches including different stress-induced
anisotropies. Within the analytical study, we consider magnetostatic effects
qualitatively, with an effective anisotropy, while they are fully treated in
the micromagnetic simulations (limited to the tubes of submicrometer diameters
however). Basic types of the periodic ordering have been established and their
presence in nanotubes of polycrystalline Permalloy and cobalt has been verified
within the simulations. The domain structure is basically determined by a
material-deposition-induced helical stress or a cooling-induced axial stress
via the volume magnetostriction while it is influenced by the distribution of
magnetic charges as well. Also, it is dependent on the initial state of the
magnetization process.
