金属纳米微粒熔化热力学性能的尺寸形状效应

SIZE AND SHAPE DEPENDENT MELTING-THERMODY- NAMIC PROPERTIES OF METALLIC NANOPARTICLES

利用表征纳米微粒形状效应的形状因子与金属纳米微粒结合能的尺寸效应表达式,建立了金属纳米微粒尺寸形状效应的熔化热力学模型,预测了金属纳米微粒存在的最小临界尺寸为rc=5r0/μ1/2{1-exp[-2Sm(∞)/3k]},最低熔化温度为Tc(r)=Tm(∞)exp[-2Sm(∞)/3k].对纳米微粒Au,In,Al和Sn熔点、熔化熵及熔化焓的预测值与实验结果相一致.

A melting-thermodynamic model is developed, which can describe the effect of size and shape of metallic nanoparticle on its melting-thermodynamic properties. It is predicted that there exist a minimum critical size r(c) = 5r(0)/mu(1/2){1 - exp[-2S(m)(infinity)/3k]} and a lowest melting temperature T-c(r) = T-m(infinity)exp[-2S(m)(infinity)/3k] for metallic nanoparticle. The present theoretical results on the melting point, the melting, entrapy and the melting enthalpy of nanoparticles Au, In, Al and Sn are consistent with the corresponding experimental values.