Clear distinctions between ferromagnetic and ferrimagnetic behaviors in a cylindrical Ising nanowire (or nanotube)

The initial susceptibility and reduced total magnetization of a cylindrical Ising nanowire (or nanotube) are investigated by the use of the effective field theory with correlations, in order to clarify their distinctions between the ferromagnetic and ferrimagnetic behaviors when the core–shell exchange coupling takes a different sign. Some common phenomena are found in the thermal variations between the two nanosystems. Whether the Neel hyperbola, valid in the paramagnetic region for a bulk ferrimagnetic material with a spinel structure, is valid for the nano-scaled ferrimagnetic systems is discussed.

► Reduced plots of total magnetization can be used for clear distinction between ferromagnetic and ferrimagnetic configurations. ► Thermal variation of the inverse paramagnetic initial susceptibility shows the hyperbolic shape with down curvature. ► The Neel hyperbola can be applied above TC, even when the size decreases to a nanometer scale.