论文标题
nd $ _ {2} $ fe $ _ {14} $ b的ce和dy取代
Ce and Dy substitutions in Nd$_{2}$Fe$_{14}$B: site-specific magnetic anisotropy from first-principles
论文作者
论文摘要
A first-principles approach combining density functional and dynamical mean-field theories in conjunction with a quasi-atomic approximation for the strongly localized 4$f$ shell is applied to Nd$_{2}$Fe$_{14}$B-based hard magnets in order to evaluate crystal-field and exchange-field parameters at rare-earth sites and their corresponding single-ion contribution to the magnetic各向异性。在纯nd $ _2 $ fe $ _ {14} $ b中，我们的计算重现了易于轴的易于轴转换；理论磁化曲线与实验定量一致。我们的研究表明，“ 2-14-1”结构中的稀土单离子各向异性非常依赖于现场，$ g $稀有地点的位置具有更大的价值。特别是，我们预测，增加$ f $和$ g $ - 点的占用率分别为$ r = $ ce和dy，会导致相应（ND，$ r $）$ _ {2} $ _ {2} $ fe $ _ {14} $ b替换化合物的磁动率增加。
A first-principles approach combining density functional and dynamical mean-field theories in conjunction with a quasi-atomic approximation for the strongly localized 4$f$ shell is applied to Nd$_{2}$Fe$_{14}$B-based hard magnets in order to evaluate crystal-field and exchange-field parameters at rare-earth sites and their corresponding single-ion contribution to the magnetic anisotropy. In pure Nd$_2$Fe$_{14}$B, our calculations reproduce the easy-cone to easy axis transition; theoretical magnetization curves agree quantitatively with experiment. Our study reveals that the rare-earth single-ion anisotropy in the "2-14-1" structure is strongly site-dependent, with the $g$ rare-earth site exhibiting a larger value. In particular, we predict that increased $f$ and $g$-site occupancy of $R=$ Ce and Dy, respectively, leads to an increase of the magnetic anisotropy of the corresponding (Nd,$R$)$_{2}$Fe$_{14}$B substituted compounds.
