Magnetic properties in an alternating-spin ferromagnetic Ising chain

Abstract Using the transfer matrix technique, we investigated the magnetic properties of a ferromagnetic Ising chain with alternating-spins (S, S ′ ) and single-ion anisotropy. We have calculated some physical quantities of interest such as the z component of the total magnetization per particle (m) and magnetic susceptibility. In the regime of low temperatures, we observed the existence of magnetization plateaus. We constructed the phase diagrams of the magnetization in terms of the magnetic field and of the single-ion anisotropy for the case 1 2 ≤ ( S , S ′ ) ≤ 9 2 . We were able to find a general rule for the magnetic transitions. We observed that the saturation value of the magnetization is m sat = ( S + S ′ ) / 2 .