Breakdown of intermediate-range order in liquid GeSe2 at high pressure
Breakdown of intermediate-range order in liquid GeSe2 at high pressure
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DOI：
10.1038/414622a
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发表时间：
2001-12
期刊：
影响因子：
64.8
通讯作者：
W. Crichton;M. Mezouar;T. Grande;S. Stølen;A. Grzechnik
中科院分区：
文献类型：
--
作者：
W. Crichton;M. Mezouar;T. Grande;S. Stølen;A. Grzechnik
对四面体配位液体的研究，特别是在压缩或淬火过程中，已经表明在液态下存在不同的相，可以通过密度和局部结构来区分。在系统中，表现出临界现象在过冷状态下，反常的行为的压缩性也预计在临界点以上，所揭示的水的模拟。液态GeSe 2是研究这两种现象的潜在吸引力系统，因为它具有二维四面体结构和异常的物理性质（包括在熔点附近的密度最小值）。在这里，我们在高温高压下的固体和液体GeSe 2的situX射线衍射测量，揭示了液体的结构是敏感的压力和异常的可压缩性是预期的。在液体GeSe 2的压缩过程中，液体的连通性从二维变为三维，导致中程有序的崩溃。熔点线以上结构的逐渐变化可能会在过冷状态下发展为一级液-液转变。
Studies of liquids with tetrahedral coordination, particularly during compression or quenching, have indicated the existence of distinct phases,,in the liquid state, distinguishable by density and local structure. In systems that exhibit critical phenomena in the supercooled state, anomalous behaviour of the compressibility is also anticipated above the critical point, as revealed by simulations of water. Liquid GeSe2is a potentially attractive system for studying both types of phenomena, given its two-dimensional tetrahedral structure and anomalous physical properties (including a density minimum near its melting point). Here we reportin situX-ray diffraction measurements of solid and liquid GeSe2at high temperature and high pressure, revealing that the structure of the liquid is sensitive to pressure and that anomalous compressibility is expected. During compression of liquid GeSe2, the connectivity of the liquid changes from two- to three-dimensional, leading to a breakdown of the intermediate-range order. The gradual change in structure above the melting line may develop to a first-order liquid–liquid transition in the supercooled regime.