Phase diagrams and magnetic properties of a cylindrical Ising nanowire: Monte Carlo and effective field treatments

The Monte Carlo simulation (MCS) technique has been used to study the phase diagrams and the magnetic properties of a cylindrical core/shell spin 1/2 Ising nanowire. The system mainly consists of two parts: the core and the surface shells, and the core is surrounded by the surface shell. The effects of the surface parameters and the random longitudinal field, on the critical and compensation behaviors, are examined. The results present rich critical behavior, which includes the first- and second-order phase transitions. It is also found that the compensation point can appear for appropriate values of the system parameters. The hysteresis curves are obtained for different temperatures (T). The triple hysteresis loops can be seen in the system for antiferromagnetic interactions. The effective filed theory (EFT) results are compared to those obtained by using the Monte Carlo Simulations. However, EFT predicts the same topology of the phase diagrams as the Monte Carlo Simulations.