Micromagnetic Simulations of Magnetization Reversal in Nd2Fe14B Magnets
Single-grain models with different dimension parameters were introduced to investigate the effects of demagnetization field on the magnetization reversal in Nd2Fe14B magnets.All the micromagnetic simulations were carried out by means of Object Oriented MicroMagnetic Framework(OOMMF).It is found that bottom shape has a little impact on the coercive field for grains with the same bottom area and height.Set as cube shape,the coercive field decreases as grain volume increases.As is known,the larger the grain volume is,the larger the effective demagnetization factor is.As a consequence,the increase of effective demagnetization factor leads to stronger demagnetization filed,which assists in the occurrence of magnetization reversal.Under the constant volume,as aspect ratio k increases,the coercive field descends in the beginning,then ascends after reaching the minimum value at k=0.65.As for the increase of the coercive field,it has been confirmed that thinner grain has smaller demagnetization factor along the height.Compared with flatter grain,it needs larger external field to rotate the moments of thinner grain.But with respect to the initial decrease of the coercive field,it is insufficient to merely analyze the value of the demagnetization field.The decrement may result from multiple factors,which still needs further and more detailed explorations.
Micromagnetic simulation Grain volume Aspect ratio Coercive field Demagnetization field Demagnetization factor
Li Lei Dong Shengzhi Han Rui Li Dong Zhu Minggang Li Wei
Division of Functional Materials Research,Central Iron & Steel Research Institute,Beijing 100081,China
国际会议
北京
英文
2022-2026
2018-09-16（万方平台首次上网日期，不代表论文的发表时间）