摘要
Two models are established to reveal the underlying coercivity mechanism for SmCo/Fe films,where one model considers a transition layer between hard and soft layers,while the other model does not consider this layer.Based on the two models,hysteresis loops,nucleation fields and coercivity are obtained by one-dimensional(1 D)and three-dimensional(3 D)micromagnetic methods.In particular,the calculated nucleation fields(H_N)and coercivity(H_C)match very well with the experimental data.It is found that the increase in the soft phase thickness(Ls)leads to a transition of the coercivity mechanism from nucleation to pinning.Such a pinning is inherently related to nucleation and has both attributes of traditional nucleation and pinning,called as a hybrid coercivity mechanism here.It is general for all hard/soft composites and can be extended to single-phased permanent magnets where defects are inevitable.
Two models are established to reveal the underlying coercivity mechanism for SmCo/Fe films,where one model considers a transition layer between hard and soft layers,while the other model does not consider this layer.Based on the two models,hysteresis loops,nucleation fields and coercivity are obtained by one-dimensional(1 D) and three-dimensional(3 D) micromagnetic methods.In particular,the calculated nucleation fields(H_N)and coercivity(H_C) match very well with the experimental data.It is found that the increase in the soft phase thickness(Ls) leads to a transition of the coercivity mechanism from nucleation to pinning.Such a pinning is inherently related to nucleation and has both attributes of traditional nucleation and pinning,called as a hybrid coercivity mechanism here.It is general for all hard/soft composites and can be extended to single-phased permanent magnets where defects are inevitable.
基金
financially supported by the National Natural Science Foundation of China(Nos.51771127,51571126 and 51772004).
