Wu Daoxiong, Lv Haifeng, Zhuo Zhiwen, Li Xingxing, Wu Xiaojun, Yang Jinlong
Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Materials for Energy Conversion, CAS Center for Excellence in Nanoscience, and School of Chemistry and Materials Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China.
Synergetic Innovation of Quantum Information & Quantum Technology, University of Science and Technology of China, Hefei, Anhui 230026, China.
J Phys Chem Lett. 2021 Apr 15;12(14):3528-3534. doi: 10.1021/acs.jpclett.1c00886. Epub 2021 Apr 2.
Assembling p orbital ferromagnetic half-metallicity and a topological element, such as a Dirac point at the Fermi level, in a single nanomaterial is of particular interest for long-distance, high-speed, and spin-coherent transportation in nanoscale spintronic devices. On the basis of the tight-binding model, we present an orbital design of a two-dimensional (2D) anionogenic Dirac half-metal (ADHM) by patterning cations with empty d orbitals and anions with partially filled p-type orbitals into a kagome lattice. Our first-principles calculations show that 2D transition-metal peroxides TM(O) (TMO, TM = Ti, Zr, Hf), containing group IVB transition-metal cations [TM] bridged with dioxygen anions [O] in a kagome structure, are stable ADHMs with a Curie temperature over 103 K. The 2/3 filled π* orbitals of dioxygen anions are ferromagnetically coupled, leading to p orbital ferromagnetism and a half-metallic Dirac point right at the Fermi level with a Fermi velocity reaching 2.84 × 10 m/s. We proposed that 2D TM(O) crystals may be extracted from ABO bulk materials containing 2D TMO layers.
在单一纳米材料中构建p轨道铁磁半金属性和拓扑元素，如费米能级处的狄拉克点，对于纳米级自旋电子器件中的长距离、高速和自旋相干输运尤为重要。基于紧束缚模型，我们通过将具有空d轨道的阳离子和具有部分填充p型轨道的阴离子图案化为 Kagome 晶格，提出了一种二维 (2D) 阴离子型狄拉克半金属 (ADHM) 的轨道设计。我们的第一性原理计算表明，二维过渡金属过氧化物TM(O)（TMO，TM = Ti、Zr、Hf），在Kagome结构中包含由双氧阴离子[O]桥接的IVB族过渡金属阳离子[TM]，是稳定的ADHM，居里温度超过103 K。双氧阴离子2/3填充的π*轨道铁磁耦合，导致p轨道铁磁性和费米能级处正好有一个半金属狄拉克点，费米速度达到2.84×10 m/s。我们提出二维TM(O)晶体可以从含有二维TMO层的ABO块状材料中提取。
