论文标题
在矩形过渡金属果酱中，由强层内相互作用响应驱动的新兴负泊松比率
Emerging negative Poisson's ratio driven by strong intralayer interaction response in rectangular transition metal chalcogenides
论文作者
论文摘要
通过负泊松比（NPR）量化的辅助行为通常归因于几何发展，其重点机制或其他机械因素被认为与电子结构无关。因此，搜索电子效应主导的辅助行为是具有挑战性的。 Herein, from state-of-the-art first-principles calculations, by studying a class of two-dimensional (2D) transition metal chalcogenides (TMCs), namely X2Y2-type (X=Cu, Ag, Au; Y=O, S, Se) rectangular TMCs (R-TMCs), we identify that the monolayer R-Cu2Se2 unconventionally demonstrates a独立于结构的各向异性NPR。相反，其他R-TMC不存在NPR。新兴的NPR归因于R-CU2SE2中内同路相互作用的强应力响应，可以将其追溯到单对电子以及在多轨道杂交下SE原子的弱电负性。新兴的NPR将使R-CU2SE2成为电子保护方面有前途的候选人，我们的研究将为设计先进的辅助材料提供宝贵的线索和有用的指导。
Auxetic behavior quantified by the negative Poisson's ratio (NPR) is commonly attributed to geometry evolution with re-entrant mechanism or other mechanical factors, which is thought to be independent of electronic structures. Thus, searching for electronic effect dominated auxetic behavior is challenging. Herein, from state-of-the-art first-principles calculations, by studying a class of two-dimensional (2D) transition metal chalcogenides (TMCs), namely X2Y2-type (X=Cu, Ag, Au; Y=O, S, Se) rectangular TMCs (R-TMCs), we identify that the monolayer R-Cu2Se2 unconventionally demonstrates a structure-independent anisotropic NPR. In contrast, the NPR is absent in other R-TMCs. The emerging NPR is attributed to the strong strain response of intralayer interaction in R-Cu2Se2, which can be traced to the lone pair electrons and weak electronegativity of Se atoms under multi-orbital hybridization. The emerging NPR would make R-Cu2Se2 a promising candidate in electronics protection, and our study would provide valuable clues and useful guidance for designing advanced auxetic materials.
