Band structure of the susceptibility, internal energy and specific heat in a mixed core/shell Ising nanotube

We investigate the temperature and the applied field dependence of the magnetic properties (magnetization, susceptibility, specific heat and internal energy) of the ferromagnetic and the antiferromagnetic cylindrical mixed spin-1/2 core and spin-1 shell Ising nanotube system using the effective field theory with correlations. We observed that the interaction parameter between the shell and the core affects the magnetic properties of the nanotube system. The hysteresis loops of the nanotube system have one, two, three and four different coercive field points; at these points, the susceptibilities, the specific heats and the internal energies of the nanotube system have two, four, six and eight distinct peaks. These peaks constitute a band structure, and the areas of the bands decrease as the temperature increases like the areas of the hysteresis loops. Furthermore, we observed that the magnetization, the susceptibility and the internal energy become zero versus applied field at a specific high temperature T=100 (T⪢Tc). Therefore, the applied fields have no effect on the magnetic properties at T=100 in the paramagnetic region. Furthermore, the constant of the slope of the m–h (hysteresis loop) curve at T⪢Tc is Curie's constant and the linear equation of the m–h curve is Curie's law.