Akademik Veri Yönetim Sistemi
ROMANIAN JOURNAL OF PHYSICS, sa.3-4, ss.9-17, 2024 (SCI-Expanded)
The spin-1 antiferromagnetic Heisenberg model was investigated by the introduction of spin operators on a square lattice in terms of a mean-field approximation (MFA). The bilinear exchange interaction parameters J(x) and J(z), the crystal field interactions D-x and D-z, and the external magnetic field components H-x and H-z along the x- and z-axes were all incorporated in the model Hamiltonian. The effects of the Dzyaloshinskii-Moriya interaction (DMI), triangle(m), were also included along the y-axis, i.e. containing the spin components only along the x- and z-axis. Various phases of the model, including ferromagnetic (FM), antiferromagnetic (AFM), and random (R) were identified by studying the thermal variations of the order-parameters, susceptibilities, specific heats, and free energy of the sublattices. The second-order phase transition temperatures between these phases were identified, in addition to the existence of first-order phase transitions. Numerous critical points, including the three-phase coexistence, were observed on the phase diagrams. The reentrant behavior was also seen for appropriate values of the system parameters.