The melting behavior of aluminum nanoparticles
The melting behavior of aluminum nanoparticles
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DOI：
10.1016/j.tca.2007.07.007
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发表时间：
2007-10-25
影响因子：
3.5
通讯作者：
Simon, S. L.
中科院分区：
文献类型：
--
作者：
Sun, J.;Simon, S. L.
利用差示扫描量热法（DSC）研究了具有氧化物钝化层的铝纳米颗粒的熔融行为。研究了宽粒径和窄粒径分布的颗粒，重均粒径范围为8 ~ 50 nm。随着颗粒尺寸的减小，熔化响应向较低温度移动，并且熔化热降低。颗粒上的氧化物涂层的作用是向铝芯施加压缩力，从而增加观察到的熔点和熔化热。的熔点下降，校正和未校正的氧化物壳的影响，是线性的颗粒半径的倒数，如吉布斯-汤姆逊方程预测，虽然只有校正的数据给出的固-液界面张力的值与文献中报道的那些。尺寸依赖的熔化热显著小于由表面张力的影响预测的熔化热，表明固体纳米颗粒处于比预期更高的能量，这可能是由于在表面处或从表面发出的晶体结构中存在缺陷或不规则性。使用我们的数据，以及使用文献中的锡纳米粒子的数据来测试这一假设。(C)2007 Elsevier B. V.保留所有权利。
The melting behavior of aluminum nanoparticles having an oxide passivation layer is examined using a differential scanning calorimetry (DSC). Both broad and narrow size-distributed particles are studied, and the weight-average particle radius ranges from 8 to 50nm. With decreasing particle size, the melting response moves towards lower temperatures and the heat of fusion decreases. The effect of the oxide coating on the particles is to apply a compressive force to the aluminum core, thereby increasing the observed melting point and the heat of fusion. The melting point depression, both corrected and uncorrected for the effects of the oxide shell, is linear with the reciprocal of particle radius, as predicted by Gibbs-Thomson equation, although only the corrected data give a value of the solid-liquid interfacial tension comparable to those reported in the literature. The size-dependent heat of fusion is significantly smaller than that predicted by the effects of the surface tension indicating that the solid nanoparticle is at a higher energy than expected, presumably due to the presence of defects or irregularities in the crystal structure at or emanating from the surface. This hypothesis is tested using our data, as well as using data in the literature for tin nanoparticles. (C) 2007 Elsevier B.V. All rights reserved.