层状硫族化合物的振动熵稳定作用：从有序空位化合物到二维层
Vibrational Entropic Stabilization of Layered Chalcogenides: From Ordered Vacancy Compounds to 2D Layers
AI总结：
本文提出由振动熵驱动的通用稳定机制，解释高温下有序空位硫族化合物倾向二维层状相的原因，并通过 ZnIn2S4、In2S3 和 Cu3VSe4 验证。
摘要：
尽管在计算和实验上发现新型二维层状材料的速度很快，但对于某一化合物为何倾向于层状结构而非非层状结构，目前仍缺乏通用判据。阐明此类判据将使人们能够识别处于二维层状相与三维体相之间跨维结构相变边缘的材料，这类材料在相变存储器件中具有潜在应用。在此，我们发现了一种由振动熵驱动的通用稳定效应：在较高温度下，该效应会使二维层状结构比三维体相结构更受青睐，并可在相竞争激烈的有序空位化合物中显现。我们以三种典型的有序空位硫族化合物 ZnIn2S4、In2S3 和 Cu3VSe4 为例，通过空位重排或沿已有空位解理，证明了这种振动熵稳定效应。二维层状相的相对振动熵优势主要源于软化的面外伸缩声子模式。
英文摘要：
Despite the rapid pace of computationally and experimentally discovering new two-dimensional layered materials, a general criteria for a given compound to prefer a layered structure over a non-layered one remains unclear. Articulating such criteria would allow one to identify materials at the verge of an inter-dimensional structural phase transition between a 2D layered phase and 3D bulk one, with potential applications in phase change memory devices. Here we identify a general stabilization effect driven by vibrational entropy that can favor 2D layered structures over 3D bulk structures at higher temperatures, which can manifest in ordered vacancy compounds where phase competition is tight. We demonstrate this vibrational-entropy stabilization effect for three prototypical ordered vacancy chalcogenides, ZnIn2S4 and In2S3, and Cu3VSe4, either by vacancy rearrangement or by cleaving through existing vacancies. The relative vibrational entropy advantage of the 2D layered phase originates mainly from softened out-of-plane dilation phonon modes.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
