A simple method of basic ferrimagnetic properties description of multilayered structures with interface-exchange modulation (Ising model, S=1/2)

We study the ferrimagnetic properties of infinite multilayered A(nA)B(nB)-structure composed of two types of magnetic materials coupled with alternating antiferromagnetic interaction. The system is considered in the frame of an Ising model in the linear cluster approximation. The expression for the free energy is obtained on using the transfer matrix method according to Bogolyubov's variational principle. The investigation of phase diagrams and thermal variation of total and layered magnetizations indicates the possible existence of multi-compensation effects. The anomalous behaviour of the initial magnetic susceptibility in a vicinity of the compensation and critical temperatures is also demonstrated.