Magnetic properties of a triangle double-layer graphene nanoisland: a Monte Carlo study

By using Monte Carlo simulations, we investigated a triangle double-layer graphene nanoisland with mixed-spin (3/2, 2) configuration. We focused on the effects of crystal-fields, exchange couplings, longitudinal magnetic fields, and temperature on the magnetic properties of the system. Various curves of magnetization, susceptibility, and internal energy as a function of temperature were obtained. We plotted the phase diagrams of blocking temperature in the different parameter planes. We found that increasing |Jab/JZ|,Jbb/JZ, and h/JZ or weakening |Db/JZ| is beneficial to improving the TB/JZ, but the TB/JZ is very insensitive to changes in the Da/JZ and Jaa/JZ. In addition, it is worth noting that the system can exhibit abundant multiple-loops hysteresis behaviors for certain physical parameters, such as triple, quadruple, quintuple, septuple hysteresis loops.