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1. Effect of gamma irradiation on the physical properties of MoS ₂ monolayer

   https://doi.org/10.1039/D3CP02925E  

   Chavda, Chintan P.; Srivastava, Ashok; Vaughan, Erin; Wang, Jianwei; Gartia, Manas Ranjan; Veronis, Georgios (August 2023, Physical Chemistry Chemical Physics)

   Two-dimensional transition metal dichalcogenides (2D-TMDs) have been proposed as novel optoelectronic materials for space applications due to their relatively light weight. MoS2 has been shown to have excellent semiconducting and photonic properties. Although the strong interaction of ionizing gamma radiation with bulk materials has been demonstrated, understanding its effect on atomically thin materials has scarcely been investigated. Here, we report the effect of gamma irradiation on the structural and electronic properties of a monolayer of MoS2. We perform Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) studies of MoS2, before and after gamma ray irradiation with varying doses and density functional theory (DFT) calculations. The Raman spectra and XPS results demonstrate that point defects dominate after the gamma irradiation of MoS2. DFT calculations elucidate the electronic properties of MoS2 before and after irradiation. Our work makes several contributions to the field of 2D materials research. First, our study of the electronic density of states and the electronic properties of a MoS2 monolayer irradiated by gamma rays sheds light on the properties of a MoS2 monolayer under gamma irradiation. Second, our study confirms that point defects are formed as a result of gamma irradiation. And third, our DFT calculations qualitatively suggest that the conductivity of the MoS2 monolayer may increase after gamma irradiation due to the creation of additional defect states. 

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2. Emerging Weyl Semimetal States in Ternary TaP _x As _{1− x} Alloys: Insights from Electronic and Topological Analysis

   https://doi.org/10.1002/qute.202300072  

   Nourizadeh, Samira_Sadat; Vaez, Aminollah; Vashaee, Daryoosh (May 2023, Advanced Quantum Technologies)

   Abstract This study presents a thorough analysis of the electronic structures of the TaP_xAs_1−xseries of compounds, which are of significant interest due to their potential as topological materials. Using a combination of first principles and Wannier‐based tight‐binding methods, this study investigates both the bulk and surface electronic structures of the compounds for varying compositions (x = 0, 0.25, 0.50, 0.75, 1), with a focus on their topological properties. By using chirality analysis, (111) surface electronic structure analysis, and surface Fermi arcs analysis, it is established that the TaP_xAs_1−xcompounds exhibit topologically nontrivial behavior, characterized as Weyl semimetals (WSMs). The effect of spin–orbit coupling (SOC) on the topological properties of the compounds is further studied. In the absence of SOC, the compounds exhibit linearly dispersive fourfold degenerate points in the first Brillouin zone (FBZ) resembling Dirac semimetals. However, the introduction of SOC induces a phase transition to WSM states, with the number and position of Weyl points (WPs) varying depending on the composition of the alloy. For example, TaP has 12 WPs in the FBZ. The findings provide novel insights into the electronic properties of TaP_xAs_1−xcompounds and their potential implications for the development of topological materials for various technological applications. 

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3. Confinement of quasi-atomic structures in Ti2N and Ti3N2 MXene electrides

   https://doi.org/10.1016/j.jpcs.2026.113534  

   Adhikari, Chandra M; Thapa, Dinesh; Alexander, Talon D; Addaman, Christopher K; Han, Shubo; Bastakoti, Bishnu P; Autrey, Daniel E; Kilina, Svetlana; Rai, Binod K; Gautam, Bhoj R (January 2026, Journal of Physics and Chemistry of Solids)

   Metal carbides, nitrides, or carbonitrides of early transition metals, better known as MXenes, possess notable structural, electrical, and magnetic properties. Analyzing electronic structures by calculating structural stability, band structure, density of states, Bader charge transfer, and work functions utilizing first principle calculations, we revealed that titanium nitride MXenes, namely TiN and TiN, have excess anionic electrons in their lattice voids, making them MXene electrides. Bulk TiN has competing antiferromagnetic (AFM) and ferromagnetic(FM) configurations with slightly more stable AFM configuration, while the TiN MXene is nonmagnetic. Although TiN favors AFM configuration with hexagonal crystal systems having point group symmetry, TiN does not support altermagnetism. The monolayer of the TiN MXene is a ferromagnetic electride. These unique properties of having non-nuclear interstitial anionic electrons in the electronic structure of titanium nitride MXene have not yet been reported in the literature. Density functional theory calculations show TiN is neither an electride, MXene, or magnetic. 

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4. Investigating magnetic van der Waals materials using data-driven approaches

   https://doi.org/10.1039/D3TC00001J  

   Bhattarai, Romakanta; Minch, Peter; Rhone, Trevor David (May 2023, Journal of Materials Chemistry C)

   In this work, we investigate magnetic monolayers of the form A i A ii B 4 X 8 based on the well-known intrinsic topological magnetic van der Waals (vdW) material MnBi 2 Te 4 (MBT) using first-principles calculations and machine learning techniques. We select an initial subset of structures to calculate the thermodynamic properties, electronic properties, such as the band gap, and magnetic properties, such as the magnetic moment and magnetic order using density functional theory (DFT). Data analytics approaches are used to gain insight into the microscopic origin of materials’ properties. The dependence of materials’ properties on chemical composition is also explored. For example, we find that the formation energy and magnetic moment depend largely on A and B sites whereas the band gap depends on all three sites. Finally, we employ machine learning tools to accelerate the search for novel vdW magnets in the MBT family with optimized properties. This study creates avenues for rapidly predicting novel materials with desirable properties that could enable applications in spintronics, optoelectronics, and quantum computing. 

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5. Superoctahedral two-dimensional metallic boron with peculiar magnetic properties

   https://doi.org/10.1039/C9CP03786A  

   Tkachenko, Nikolay V.; Steglenko, Dmitriy; Fedik, Nikita; Boldyreva, Natalia M.; Minyaev, Ruslan M.; Minkin, Vladimir I.; Boldyrev, Alexander I. (September 2019, Physical Chemistry Chemical Physics)

   Among the diversity of new materials, two-dimensional crystal structures have been attracting significant attention from the broad scientific community due to their promising applications in nanoscience. In this study we predict a novel two-dimensional ferromagnetic boron material, which has been exhaustively studied with DFT methods. The relaxed structure of the 2D-B 6 monolayer consists of slightly flattened octahedral units connected with 2c-2e B–B σ-bonds. The calculated phonon spectrum and ab initio molecular dynamics simulations reveal the thermal and dynamical stability of the designed material. The calculation of the mechanical properties indicate a relatively high Young's modulus of 149 N m −1 . Moreover, the electronic structure indicates the metallic nature of the 2D-B 6 sheets, whereas the magnetic moment per unit cell is found to be 1.59 μ B . The magnetism in the 2D-B 6 monolayer can be described by the presence of two unpaired delocalized bonding elements inside every distorted octahedron. Interestingly, the nature of the magnetism does not lie in the presence of half-occupied atomic orbitals, as was shown for previously studied magnetic materials based on boron. We hope that our predictions will provide promising new ideas for the further fabrication of boron-based two-dimensional magnetic materials. 

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