宽禁带 w-AlN 中铁磁性工程用于自旋电子学应用：来自 DFT 计算的见解
Engineering Ferromagnetism in Wide Bandgap w-AlN for Spintronic Applications: Insights from DFT Calculations
浏览论文内容
中文总结 AI 辅助
本研究通过 DFT 计算探索 w-AlN 掺杂 Cr、Ru、Rh 的磁性，发现 Cr 掺杂在宽浓度范围呈铁磁态并随浓度演化出绝缘、半金属到金属转变，为自旋电子学材料设计提供理论依据。
中文摘要 AI 辅助
自旋电子学推动了对功能材料的探索，追求室温稀磁半导体以实现实用、节能的器件。本文利用自旋极化密度泛函理论计算和超胞模型，对掺杂 Cr、Ru 和 Rh 原子的 w-AlN 的磁性质进行了理论研究。作为费米能级函数的点缺陷形成能计算预测，Cr4+、Ru4+ 和 Rh3+ 是取代 w-AlN 中 Al 的最有利电荷态。在这些优选电荷态下，Cr 掺杂的 AlN 在宽浓度范围（Al 的 1.85% 至 16.67%）内以铁磁态稳定存在，这有利于自旋电子学器件。相反，Ru 和 Rh 掺杂的 AlN 相对于反铁磁态，其铁磁态不稳定。对电子态密度的进一步研究揭示了一个引人入胜的演化：对于 Cr 浓度低于 5.56% 时，费米能级位于带隙内，直接位于价带最大值之上，使系统保持绝缘性。在 7.40% 至 12.96% 之间，它转变为高自旋半金属态，最终在 16.67% Cr 时转变为普通金属。这种行为在 Ru 和 Rh 掺杂系统的反铁磁模型的态密度中不存在，其中绝缘和金属行为反而随着浓度的变化而出现非顺序性。
英文摘要
Spintronics drives the search for functional materials, pursuing room-temperature dilute magnetic semiconductors to realize practical, energy-efficient devices. This paper presents a theoretical investigation into the magnetic properties of w-AlN doped with Cr, Ru, and Rh atoms, using spin-polarized density functional theory calculations with supercell models. Calculations of point-defect formation energies as a function of the Fermi level predict that Cr4+, Ru4+, and Rh3+ are the most favorable charge states substituting Al in w-AlN. With these preferred charge states, Cr-doped AlN is stable in the ferromagnetic state, preferable for spintronic devices, across a wide concentration range (1.85 to 16.67% of Al). Conversely, Ru- and Rh-doped AlN are unstable in the ferromagnetic state relative to the antiferromagnetic state. Further investigation into the electronic density of states reveals a fascinating evolution: for Cr concentrations below 5.56%, the Fermi level resides within the band gap directly above the valence band maximum, keeping the system insulating. It transitions to a high-spin half-metallic state between 7.40% and 12.96%, and finally transforms into a normal metal at 16.67% Cr. This behavior is absent in the DOS of the antiferromagnetic model of Ru- and Rh-doped systems, where insulating and metallic behaviors instead appear non-sequentially with varying concentrations.
发表机构
- Indira Gandhi Centre for Atomic Research, HBNI（印度原子能研究中心，HBNI）
机构由 AI 辅助整理，请以论文原文为准。
