Study of magnetic properties for co double-nanorings: Monte Carlo simulation

• A double-nanorings structure (named as d-N-rings) was proposed to construct cobalt nanometer thin film.
• Monte Carlo method combining with FFTM method was used to simulate magnetic properties of the Co d-N-rings.
• Magnetization dynamic processes of the Co d-N-rings were obtained and interpreted through the evolutionary process of spin configurations.
• Geometric dimensions deeply influence the magnetization behavior of the Co d-N-rings, which is determined by the change of both SCs and exchange interaction.

In this paper, cobalt double-nanorings (Co d-N-rings) structure model was constructed. Based on Monte-Carlo simulation (MC) method combining with Fast Fourier Transformation and Micromagnetism (FFTM) method, the magnetic properties of Co d-N-rings with different geometric dimensions have been studied. The simulated results indicate that, the magnetization steps in hysteresis loops is the result of the special spin configurations (SCs), i.e., onion-type state and vortex-type state, which are very different from that in many other nanostructures, such as nanometer thin-films, nanotubes, etc. Besides, Co d-N-rings with different geometric dimensions present interesting magnetization behavior, which is determined by the change of both SCs and exchange interaction in Co d-N-rings.