Monte Carlo Method Study of Thin Films of The Spin-1 Ashkin Teller Model in the Presence of the Crystal Field

Using Monte Carlo simulations based on the Metropolis algorithm, we have investigated magnetic properties and phase diagrams of the spin-1 Ashkin Teller model magnetic thin films. The effects of the crystal field D/J_2band four-spins coupling (J_4s/J_2b, J_4b/J_2b), has been studied in detail. Therefore, the phase diagrams in the ((k_B T_c)/J_2b, J_2s/J_2b ) plane, exhibits the special point (R_s=J_2s/J_2b)_sp, for different values of D/J_2b, wherein all film thicknesses having the same critical temperature. In addition, the magnetization profiles present a first order phase transition behavior. Then, we found rich phase diagrams with first- and second-order phase transitions that meet at tricritical points, that are dependent on the film thickness N.