A simple method of complex ferrimagnetic properties description of AB1AB2-superlattice structures with a strong perpendicular anisotropy contribution (Blume–Capel model)

We have studied the ferrimagnetic spin-1 AB1AB2 superlattice in the presence of perpendicular single-ion anisotropy (Blume–Capel model) to have a direct evidence of the existence of multicompensation and tricritical effects. We present the theory based on the use of the exact solution for spin-1 Ising linear chain in external magnetic field. The free energy is calculated from the Bogolyubovʹs variational principle in frame of the transfer matrix method. Then, we obtain the description of the second as well as first-order phase transition, together with the layered and total magnetization curves. Our results (phase diagrams) indicate the possible existence of 1–3-compensation point effects for particular values of magnetic structure parameters. Mainly, the contribution of the perpendicular single-ion anisotropy is verified.