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arXiv 0903.2728cond-mat.dis-nncond-mat.stat-mech
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一种简单单原子液体的玻璃形成和晶化

Glass Formation and Crystallization of a Simple Monatomic Liquid

Tomoko Mizuguchi, Takashi Odagaki

摘要:

利用分子动力学模拟,在较宽的温度范围内研究了具有双阱相互作用势的二维单原子系统。将该体系在熔融温度以上熔融并平衡,然后以几种冷却速率将其骤冷至低于熔融温度Tm 88%的温度以产生非晶态。当系统以恒定速率加热时,测量作为温度的函数的各种热力学量。通过能量的突然增加观察到玻璃化转变,并且示出Tg是非晶态制备过程中冷却速率的递增函数。在较高温度区,体系逐渐转变为晶体,时间-温度-转变(TTT)曲线呈典型的鼻状。发现在低于熔点Tm 14~15%的温度下,转变为晶态的时间最短,在足够低的温度下,转变时间远大于可用的CPU时间。这表明实现了长寿命的玻璃态。

英文摘要:

A simple monatomic system in two dimensions with a double-well interaction potential is investigated in a wide range of temperature by molecular dynamics simulation. The system is melted and equilibrated well above the melting temperature, and then it is quenched to a temperature 88% below the melting temperature Tm at several cooling rates to produce an amorphous state. Various thermodynamic quantities are measured as a function of temperature while the system is heated at a constant rate. The glass transiton is observed by a sudden increase of the energy and Tg is shown to be an increasing function of the cooling rate in the preparation process of the amorphous state. In a relatively-high temperature region, the system gradually transforms into crystals, and the time-temperature-transformation(TTT) curve shows a typical nose shape. It is found that the transformation time to a crystalline state is the shortest at a temperature 14~15% below the melting temperature Tm and that at sufficiently low temperatures the transformation time is much longer than the available CPU time. This indicates that a long-lived glassy state is realized.

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。

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