Melting and Glass Transition for Ni Clusters

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• 作者：Yuyong Teng ; Xianghua Zeng ; Haiyan Zhang ; Deyan Sun
• 刊名：Journal of Physical Chemistry B
• 出版年：2007
• 出版时间：March 8, 2007
• 年：2007
• 卷：111
• 期：9
• 页码：2309 - 2312
• 全文大小：133K
• 年卷期：v.111,no.9(March 8, 2007)
• ISSN：1520-5207

文摘

The melting of Ni_N clusters (N = 29, 50-150) has been investigated by using molecular dynamics (MD)simulations with a quantum corrected Sutton-Chen (Q-SC) many-body potential. Surface melting for Ni₁₄₇,direct melting for Ni₇₉, and the glass transition for Ni₂₉ have been found, and those melting points are equalto 540, 680, and 940 K, respectively. It shows that the melting temperatures are not only size-dependent butalso a symmetrical structure effect; in the neighborhood of the clusters, the cluster with higher symmetry hasa higher melting point. From the reciprocal slopes of the caloric curves, the specific heats are obtained as4.1k_B per atom for the liquid and 3.1k_B per atom for the solid; these values are not influenced by the clustersize apart in the transition region. The calculated results also show that latent heat of fusion is the dominanteffect on the melting temperatures (T_m), and the relationship between S and L is given.