Shin Hyeondeok, Ganesh Panchapakesan, Kent Paul R C, Benali Anouar, Bhattacharya Anand, Lee Ho Nyung, Heinonen Olle, Krogel Jaron T
Computational Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Phys Chem Chem Phys. 2024 Feb 22;26(8):6967-6976. doi: 10.1039/d3cp03477a.
As the only semimetallic d-based delafossite, AgNiO has received a great deal of attention due to both its unique semimetallicity and its antiferromagnetism in the NiO layer that is coupled with a lattice distortion. In contrast, other delafossites such as AgCoO are insulating. Here we study how the electronic structure of AgNiCoO alloys vary with Ni/Co concentration, in order to investigate the electronic properties and phase stability of the intermetallics. While the electronic and magnetic structure of delafossites have been studied using density functional theory (DFT), earlier studies have not included corrections for strong on-site Coulomb interactions. In order to treat these interactions accurately, in this study we use Quantum Monte Carlo (QMC) simulations to obtain accurate estimates for the electronic and magnetic properties of AgNiO. By comparison to DFT results we show that these electron correlations are critical to account for. We show that Co doping on the magnetic Ni sites results in a metal-insulator transition near ∼0.33, and reentrant behavior near ∼ 0.66.
作为唯一的半金属d基铜铁矿，AgNiO因其独特的半金属性以及与晶格畸变耦合的NiO层中的反铁磁性而备受关注。相比之下，其他铜铁矿如AgCoO是绝缘的。在这里，我们研究AgNiCoO合金的电子结构如何随Ni/Co浓度变化，以便研究金属间化合物的电子性质和相稳定性。虽然已经使用密度泛函理论（DFT）研究了铜铁矿的电子和磁结构，但早期研究并未包括对强在位库仑相互作用的修正。为了准确处理这些相互作用，在本研究中我们使用量子蒙特卡罗（QMC）模拟来获得AgNiO电子和磁性质的准确估计。通过与DFT结果比较，我们表明这些电子关联是需要考虑的关键因素。我们表明，在磁性Ni位点上的Co掺杂导致在0.33附近出现金属-绝缘体转变，并在0.66附近出现再入行为。
