Magnetic properties of an Olympicene structure: Monte Carlo simulations

Abstract

The magnetic properties and the hysteresis loops of a core–shell of an Olympicene structure are studied using Monte Carlo simulations, made of spins S=3 core surrounded by spins σ=7∕2 shell with antiferromagnetic intermediate exchange coupling. We analyze the ground state phase diagrams and found that from 7×8=56 possible configurations, only 20 configurations are stable. The compensations and critical temperatures of our system have been found. We show the existence of the compensation temperature and its dependence on the exchange coupling interactions. We investigate the effects of the crystal field, temperature, shell interactions and intermediate coupling on the hysteresis curves. A number of characteristic behaviors are found, such as the occurrence of single and triple hysteresis loops for appropriate values of the system parameters. The effect of size has been studied on the critical temperatures and magnetic coercive field. In these studied the some behaviors are found such as the multiples hysteresis cycles etc. The standard deviation with the standard error of the mean were applied.