High-throughput discovery of thermodynamically stable 1D magnetic chains in transition-metal chalcogenides and halides

High-throughput discovery of thermodynamically stable 1D magnetic chains in transition-metal chalcogenides and halides

Canbo Zong#, Deping Guo#, Renhong Wang, Weihan Zhang, Jiaqi Dai, Zhongqin Zhang, Cong Wang*, Xianghua Kong, and Wei Ji*

The search for novel one-dimensional (1D) materials with exotic physical properties is crucial for advancing nanoelectronics and spintronics. Here, we perform a comprehensive high-throughput, first-principles study to explore the vast landscape of 1D transition-metal chalcogenides and halides. Starting with 6,832 candidate structures derived from 28 metals and 8 non-metals, we systematically evaluated their thermodynamic stability by comparing the formation energies of 1D chains against competing 2D phases, mimicking thermodynamic selectivity during nucleation. This screening identified 210 stable 1D magnetic chains. Furthermore, representation learning models revealed that chemical stoichiometry and the electron affinity of the non-metal element are key factors governing 1D stability. The stable materials exhibit a rich spectrum of properties, including diverse magnetic orders (FM, AFM) and Luttinger compensated antiferromagnetism in MnTe. We discovered 20 ferroelastic chains, with FeTe showing a giant magnetostriction of -5.57 %. Other emergent phenomena include Charge Density Wave (CDW) chains in FeTe and NiSe. Finally, our findings propose concrete platforms for quantum applications, such as the predicted realization of Majorana zero modes in a ferromagnetic CrCl2 chain on a superconducting NbSe2 substrate.

Robust High-Spin State in One-Dimensional CrX2 (X=Cl, Br, I) at the Single-Chain Limit

Robust High-Spin State in One-Dimensional CrX2 (X=Cl, Br, I) at the Single-Chain Limit

Yangjin Lee#, Linxuan Li#, Weihan Zhang#, Uje Choi, Kihyun Lee, Young-Min Kim, Wei Ji*, Wu Zhou*, Kwanpyo Kim*, and Alex Zettl*

Low-dimensional magnetic materials have garnered significant interest due to their unique physical properties and potential applications. Nevertheless, the synthesis of one-dimensional (1D) magnetic materials presents challenges, and the properties of these 1D materials at the single-chain limit have not been well investigated. We here explore experimentally and theoretically 1D CrX2 (X= Cl, Br, I) magnetic single-chains residing within carbon nanotubes. Single chains of CrX2 are confirmed by atomic-resolution scanning transmission electron microscopy imaging and spectroscopy analysis. Electron energy loss spectroscopy clearly reveals the high-spin state of Cr atoms within the chain. Notably, we present the first precise measurement and analysis of Cr spin state at the single-chain level, revealing that these spin states can be controlled by the local atomic bonding configuration (CrX2 versus CrX3 phases). Density functional theory calculations support the structural stability and provide the magnetic and electronic properties of the 1D CrX2 chains.

Semiregular tessellation of electronic lattices in untwisted bilayer graphene under anisotropic strain gradients

Semiregular tessellation of electronic lattices in untwisted bilayer graphene under anisotropic strain gradients

Zeyu Liu(刘泽宇)#, Xianghua Kong(孔祥华)#,*, Zhidan Li(李志聃), Zewen Wu(吴泽文), Linwei Zhou(周霖蔚), Cong Wang(王聪), and Wei Ji(季威)*

Low-dimensional magnetic materials have garnered significant interest due to their unique physical properties and potential applications. Nevertheless, the synthesis of one-dimensional (1D) magnetic materials presents challenges, and the properties of these 1D materials at the single-chain limit have not been well investigated. We here explore experimentally and theoretically 1D CrX2 (X= Cl, Br, I) magnetic single-chains residing within carbon nanotubes. Single chains of CrX2 are confirmed by atomic-resolution scanning transmission electron microscopy imaging and spectroscopy analysis. Electron energy loss spectroscopy clearly reveals the high-spin state of Cr atoms within the chain. Notably, we present the first precise measurement and analysis of Cr spin state at the single-chain level, revealing that these spin states can be controlled by the local atomic bonding configuration (CrX2 versus CrX3 phases). Density functional theory calculations support the structural stability and provide the magnetic and electronic properties of the 1D CrX2 chains.

Intralayer Negative Poisson’s Ratio in 2D Black Arsenic by Strain Engineering

Intralayer Negative Poisson’s Ratio in 2D Black Arsenic by Strain Engineering

Small Strucutures (2023), DOI: 10.1002/sstr.202300178

Jingjing Zhang#, Weihan Zhang#, Leining Zhang#, Guoshuai Du, Yunfei Yu, Qinglin Xia, Xu Wu, Yeliang Wang, Wei Ji, Jingsi Qiao*, Feng Ding*, Yabin Chen*

Abstract:

Negative Poisson’s ratio as the anomalous characteristic generally exists in artificial architectures, such as re-entrant and honeycomb structures. The structures with negative Poisson’s ratio have attracted intensive attention due to their unique auxetic effect and many promising applications in shear-resistant and energy absorption fields. However, experimental observation of negative Poisson’s ratio in natural materials barely happens, although various 2D layered materials are predicted in theory. Herein, the anisotropic Raman response and the intrinsic intralayer negative Poisson’s ratio of 2D natural black arsenic (b-As) via strain engineering strategy are reported. The results are evident by the detailed Raman spectrum of b-As under uniaxial strain together with density functional theory calculations. It is found that b-As is softer along the armchair than zigzag direction. The anisotropic mechanical features and van der Waals interactions play essential roles in strain-dependent Raman shifts and negative Poisson’s ratio in the natural b-As along zigzag direction. This work may shed a light on the mechanical properties and potential applications of 2D puckered materials.

DOI: 10.1002/sstr.202300178