Ali Yigit

Spin-3/2 Ising model AFM/AFM two-layer lattice with crystal field

The spin-3/2 Ising model is investigated for the case of antiferromagnetic (AFM/AFM) interactions on the two-layer Bethe lattice by using the exact recursion relations in the pairwise approach for given coordination numbers q = 3, 4 and 6 when the layers are under the influences of equal external magnetic and equal crystal fields. The ground state (GS) phase diagrams are obtained on the different planes in detail and then the temperature-dependent phase diagrams of the system are calculated accordingly. It is observed that the system presents both second- and first-order phase transitions for all q, therefore, tricritical points. It is also found that the system exhibits double-critical end points and isolated points. The model also presents two N?el temperatures, TN, and the existence of which leads to the reentrant behaviour.

THE GROUND-STATE PHASE DIAGRAMS OF SPIN-3/2 ISING MODEL ON A FM/AFM TWO-LAYER LATTICE WITH CRYSTAL FIELD

The ground-state (GS) phase diagrams of spin-3/2 Ising model for ferromagnetic/antiferromagnetic (FM/AFM) interactions on a two-layer lattice are studied under a constant magnetic field by varying the crystal field values for general coordination number q in detail. Thus, it is found that the system exhibits twenty-nine topologically different GS configurations according to their GS phase diagrams obtained in the (J2/J1, J3/qJ1) planes. As the crystal field becomes more and more negative, the remaining phase configurations in the phase diagrams include only spin ±1/2 values as expected.