论文标题
Hubbard $ u $和Hund Exchange $ J $的Ab-Initio计算本地瞬间磁铁：基于MN的Full Heusler化合物的情况
Ab-initio calculation of the Hubbard $U$ and Hund exchange $J$ in local moment magnets: The case of Mn-based full Heusler compounds
论文作者
论文摘要
基于MN的全力氏度化合物具有明确定义的局部原子MN矩，因此，预期局部D电子之间的相关效应在确定这些材料的电子和磁性特性方面起着重要作用。在X2MNZ Full Heusler化合物的情况下，使用AB-Initio的计算与约束的随机相近似（CRPA）方法结合使用，我们计算有效现场库仑相互作用参数（Hubbard U和Hund Exchange J）的强度，并且是Ni，pd或pd或z是一个或z是一项，SN，SN，SN，SN，SN，SN，SN，SN，SN，SN，SN，SN。我们表明，与基本体积MN相比，Heusler化合物中的Z元素（或SP元素）显着降低了MN 3D电子的Hubbard U参数强度。相反，Sp-Atom对Ni，Cu或Pd Valence D电子的U参数强度的影响在基本体积值方面并不那么重要。所有过渡金属原子的U值随着SN-SB-TE序列中的SP电子数的增加而降低。我们的CRPA计算表明，尽管它们定义明确的局部磁矩，但基于MN的完整啤酒合金属于弱相关材料的类别。
Mn-based full Heusler compounds possess well-defined local atomic Mn moments, and thus the correlation effects between localized d electrons are expected to play an important role in determining the electronic and magnetic properties of these materials. Employing ab-initio calculations in conjunction with the constrained random-phase approximation (cRPA) method, we calculate the strength of the effective on-site Coulomb interaction parameters (Hubbard U and Hund exchange J) in the case of X2MnZ full Heusler compounds with X being one of Ni, Pd or Cu, and Z being one of In, Sn, Sb or Te. We show that the Z element (or sp element) in Heusler compounds significantly reduces the strength of the Hubbard U parameter for Mn 3d electrons compared to the elementary bulk Mn. On the contrary, the effect of the sp-atom on the strength of the U parameter of Ni, Cu or Pd valence d electrons is not so substantial with respect to the elementary bulk values. The U values for all transition metal atoms decrease with increasing sp electron number in the In-Sn-Sb-Te sequence. Our cRPA calculations reveal that despite their well-defined local magnetic moments, the Mn-based full Heusler alloys fall into the category of the weakly correlated materials.
