Thermodynamic and magnetic properties of a mixed Ising system on a triangular array in presence of longitudinal field

Using the effective-field theory with correlations (EFT), the effects of a longitudinal field on the magnetic properties of a ferrimagnetic system, consisting of two triangular magnetic sublattices A and B (with a coordination number z=6) with spins SA=12 and SB=32, are investigated. The influence of the crystal-field interaction DB within the sublattice B and the longitudinal applied field on these properties are examined. We determine the total magnetization in absence and under the magnetic field, whereas the initial susceptibility is carried out. The Arrott plots shapes in the (H0/M,M2)-plane are determined. They indicate a region of strong competition between the inter-sublattices (JAB) exchange coupling and the applied field. Other striking features have been revealed in the magnetization behavior especially near the critical and the compensation temperatures.