Manganese-based MXenes are promising two-dimensional materials due to the broad palette of their magnetic phases and the possibility of experimental preparation because the corresponding MAX phase was already prepared. Here, we systematically investigated geometrical conformers and spin solutions of oxygen-terminated Mn$_2$C MXene and performed subsequent many-body calculations to obtain reliable electronic and optical properties. Allowing energy-lowering using the correct spin ordering via supercell magnetic motifs is essential for the Mn$_2$CO$_2$ system. The stable ground-state Mn$_2$CO$_2$ conformation is antiferromagnetic (AFM) one with zigzag lines of up and down spins on Mn atoms. The AFM nature is consistent with the parent MAX phase and even the clean depleted Mn$_2$C sheet. Other magnetic states and geometrical conformations are energetically very close, providing state-switching possibilities in the material. Subsequent many-body GW and Bethe-Salpeter equation (BSE) calculations provide indirect semiconductor characteristics of AFM Mn$_2$CO$_2$ with a fundamental gap of 2.1 eV (and a direct gap of 2.4 eV), the first bright optical transition at 1.3 eV and extremely strongly bounded (1.1 eV) first bright exciton. Mn$_2$CO$_2$ absorbs efficiently the whole visible light range and near ultraviolet range (between 10 - 20%).
High-Tc Superconductivity in Functionalized Out-of-Plane Ordered Double Transition Metal MXenes
University of Tehran（德黑兰大学）；Binghamton University-SUNY（宾厄姆顿大学（纽约州立大学））；Yokohama National University（横滨国立大学）；Institut Teknologi Bandung（印尼万隆理工学院）；JAIST（石川县立大学）；Institute of Science Tokyo（东京科学大学）；Institute for Research in Fundamental Sciences (IPM)（伊朗基础科学研究院）
Oxygen Functionalization-induced Crossover in the Tensile Properties of thinnest 2D Ti2C MXene
过渡金属碳化物/氮化物（MXenes）是一种新开发的二维（2D）材料，具有技术上坚固的性能，可以通过平面表面功能化进行微调。在本文中，氧（O-）官能化对最薄的2D Ti 2C MXene的拉伸机械特性的关键作用通过基于第一性原理的ReaxFF力场的分子动力学（MD）模拟来探索。结果表明，Ti_2C板材具有独特的拉伸力学行为，并随O-官能化含量和拉伸方向的不同而显著变化。在两个加载方向上，杨氏模量、破坏强度和破坏应变存在明显的交叉。有趣的是，在扶手椅定向载荷下，在Ti_2C区发生1 T到1 T '相的结构转变，这在许多过渡金属二硫属化物中已经观察到。然而，在Z字形方向的应变，两个不同的结构转变发生在原始的和完全O-官能化的Ti 2C片，分别。当载荷被移除时，这三种结构转变是可逆的，并且通过键构型的分析来严格理解它们。该研究为功能化MXene的力学行为和结构转变提供了重要的见解。
Multiferroic properties of oxygen functionalized magnetic i-MXene
二维多铁性材料继承了低维材料和磁电材料的优良物理性质，并以其独特的结构超越了三维材料。这里，基于密度泛函理论计算，MXene衍生物，即，i-MXene（Ta $_{2/3}$ Fe $_{1/3}$）$_2$ CO $_2$被预测为I型多铁性材料。源自可靠的$5d^0$规则，其铁电性是稳健的，具有沿a轴高达$\sim12.33$ $μ$ C/cm $^2$的中等极化，其可以容易地切换并且可以在室温以上持续。其磁基态为层状反铁磁性。尽管它是I型多铁性材料，但它的Néel温度可以通过顺电-铁电转变显着调节，表现出一种固有的磁电耦合。这种磁电效应源于传统的磁致伸缩效应，但交换阻挫却意外地放大了这种效应。我们的工作不仅揭示了非平凡的磁电机制，而且为在二维极限下寻找更多的多铁性材料提供了一种策略。
Surface-oxygen-passivation driven large anomalous Hall conductivity (AHC) in nitride MXenes: Can AHC be a tool to determine functional groups in 2D ferro(i)magnets?
Exploring a novel class of Janus MXenes by first principles calculations: structural, electronic and magnetic properties of Sc2CXT, X=O, F, OH; T=C, S, N
General and scalable vapor etching and transformation platform for two-dimensional materials
School of Materials Science and Engineering, Beihang University（北京航空航天大学材料科学与工程学院）；Linköping University（林雪平大学）；JiNan SCMXene Tech. Co., Ltd.（济南SCMXene科技有限公司）
Recently, a group of MAX phases, (Mo$_{2/3}$Y$_{1/3}$)$_2$AlC, (Mo$_{2/3}$Sc$_{1/3}$)$_2$AlC, (W$_{2/3}$Sc$_{1/3}$)$_2$AlC, (W$_{2/3}$Y$_{1/3}$)$_2$AlC, and (V$_{2/3}$Zr$_{1/3}$)$_2$AlC, with in-plane ordered double transition metals, named iMAX phases, have been synthesized. Experimentally, some of these MAX phases can be chemically exfoliated into two-dimensional (2D) single- or multilayered transition metal carbides, so-called MXenes. Accordingly, the 2D nanostructures derived from iMAX phases are named iMXenes. Here, we investigate the structural stabilities and electronic structures of th…
M\textbf{\textit{O}}enes family materials with Dirac nodal loop, strong light-harvesting ability, long carrier lifetime and conduction-band valley spin splitting
