| Summary: | 碩士 === 國立彰化師範大學 === 光電科技研究所 === 100 === In this work, we study on magnetic switching behavior and the influemce of asymmetry of ring on switching mechanism in asymmetric Premalloy Ring. By introducing an inner hole, which shift along its diameter at y-axis to break the symmetric structure in the ring. To analyse its reversal mechanisms in M-H loop by MOKE measure system and OOMMF programs. There many distinct magnetic states, such as ” onion state”, vortex state (flux-closure state), and so on. First, we study on the influence of shift length of inner hole. It was observed that the nucleation field (Hn) and annihilation field (Han) both are proportional to shift length.
Second, we investigate the influence of different inner diameter on magnetic reversal behavior. In our opinion, the shape anisotropy result in the decrement of Hn and increasing Han. Finally, our results show that the exchange energy of magnetism, Eex, with different shift length. There are some peak in Eex, where occurred at sharp in M-H loop. We use MOKE system and OMMF program to analyze the magnetic reversal behaviors, and the trend of experiment data agree well with simulation results.
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