Recrystallization of picosecond laser-melted ZnO nanoparticles in a liquid: A molecular dynamics study
Recrystallization of picosecond laser-melted ZnO nanoparticles in a liquid: A molecular dynamics study
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DOI：
10.1063/1.3407438
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发表时间：
2010-04-28
影响因子：
4.4
通讯作者：
Pan, Heng
中科院分区：
文献类型：
--
作者：
Hu, Ming;Poulikakos, Dimos;Pan, Heng
我们采用分子动力学模拟研究了氧化锌（ZnO）纳米粒子在液体十四烷中的皮秒激光加热后的快速熔化和随后的冷却过程。研究了两个相邻的熔融纳米颗粒聚结成一个更大的颗粒和后者在冷却时的重结晶。重结晶后，纳米粒子的结构由六方纤锌矿结构转变为面心立方结构。通过分析加热/冷却过程，我们证明了颗粒尺寸对纳米颗粒与周围液体之间的界面热导率以及凝固起始和凝固完成温度有很大的影响。我们还研究了在颗粒表面附近的周围液体层的热行为。沸腾的液体层被发现在极高的热通量的情况下。(C)2010年美国物理学会。[doi 10.1063/1.3407438]
We employ molecular dynamics simulation to investigate the rapid melting and subsequent cooling process of zinc oxide (ZnO) nanoparticles in liquid tetradecane upon picosecond laser heating. The coalescence of two neighboring melted nanoparticles into a larger particle and the recrystallization of the latter upon cooling were studied. Severe undercooling and distinct recalescence occurs and the structure of the nanoparticle transforms from its initial hexagonal wurtzite structure to a face-centered cubic structure after recrystallization. By analyzing the heating/cooling process, we demonstrated that the particle size has a large impact on the interfacial thermal conductance between the nanoparticle and the surrounding liquid, as well as on the solidification initiation and solidification completion temperatures. We also investigated the thermal behavior of the surrounding liquid layer at the neighborhood of the particle surface. Boiling of the liquid layer was found in the case of extremely high heat fluxes. (C) 2010 American Institute of Physics. [doi:10.1063/1.3407438]