Explaining Browns paradox in NdFeB magnets from micromagnetic simulations

We present the results of a systematic investigation into how coercivity and maximum energy product NdFeB permanent magnets are affected by magnetic geometric microscopic properties. The based on numerical micromagnetic simulations carried out with open source framework MagTense. considered artificially generated realistic microstructures for which we can control number crystal grains as well thickness intergrain region. Based variations exchange constant, easy axis orientation, grain boundary width material properties, indicate that while all these contribute to reduction coercivity, orientation has largest influence. For this, if is distributed within cone an opening angle 15°, enough reduce 1 T. Regarding product, layer were seen have influence, constant only very weakly influencing product. Our analysis thus methodically clarifies different factors contributing value when compared theoretical limit, discrepancy known Brown’s paradox.