论文标题
Fe-Doped $α$ -Mno $ _2 $中的场地哈伯德互动的关键作用
Pivotal Role of Intersite Hubbard Interactions in Fe-doped $α$-MnO$_2$
论文作者
论文摘要
我们使用具有扩展的Hubbard功能的密度官能理论，对原始和Fe掺杂的$α$ -MNO $ _2 $的结构，电子和磁性的第一原理研究进行了研究。现场$ u $和intersite $ v $哈伯德参数取决于第一原理，并在Löwdin-Ottroctalizate的原子轨道的基础上使用密度官能扰动理论进行自谐度确定。对于原始的$α$ -MNO $ _2 $，我们发现所谓的C2-非旋转构型是最有益的，这与实验观察到的抗磁磁接地状态一致。对于Fe型的$α$ -Mno $ _2 $ _2 $两种类型的掺杂：Fe插入$ 2 \ times 2 $ times 2 $隧道和MN的FE替换。 We find that the interstitial doping preserves the C2-AFM spin configuration of the host lattice only when both onsite $U$ and intersite $V$ Hubbard corrections are included, while for the substitutional doping the onsite Hubbard $U$ correction alone is able to preserve the C2-AFM spin configuration of the host lattice.在间隙和替代掺杂的情况下，FE的氧化状态分别为$+2 $和$+4 $，而Mn的氧化状态在两种情况下均为$+4 $。这项工作为精确研究其他MNO $ _2 $多晶型物和复杂的过渡金属化合物铺平了道路，当时$ 3D $电子的定位在与配体有强共价相互作用的情况下发生。
We present a first-principles investigation of the structural, electronic, and magnetic properties of the pristine and Fe-doped $α$-MnO$_2$ using density-functional theory with extended Hubbard functionals. The onsite $U$ and intersite $V$ Hubbard parameters are determined from first principles and self-consistently using density-functional perturbation theory in the basis of Löwdin-orthogonalized atomic orbitals. For the pristine $α$-MnO$_2$ we find that the so-called C2-AFM spin configuration is the most energetically favorable, in agreement with the experimentally observed antiferromagnetic ground state. For the Fe-doped $α$-MnO$_2$ two types of doping are considered: Fe insertion in the $2 \times 2$ tunnels and partial substitution of Fe for Mn. We find that the interstitial doping preserves the C2-AFM spin configuration of the host lattice only when both onsite $U$ and intersite $V$ Hubbard corrections are included, while for the substitutional doping the onsite Hubbard $U$ correction alone is able to preserve the C2-AFM spin configuration of the host lattice. The oxidation state of Fe is found to be $+2$ and $+4$ in the case of the interstitial and substitutional doping, respectively, while the oxidation state of Mn is $+4$ in both cases. This work paves the way for accurate studies of other MnO$_2$ polymorphs and complex transition-metal compounds when the localization of $3d$ electrons occurs in the presence of strong covalent interactions with ligands.
