Department of Applied Physics, Chalmers University of Technology, S-412 96 Goteborg, Sweden.
Nano Lett. 2010 Mar 10;10(3):931-6. doi: 10.1021/nl100044k.
Using the localized surface plasmon resonance as a probe in solid and liquid Sn nanoparticles of 107 nm diameter and 52 nm height, we have studied their kinetics of melting and freezing at temperature ramps and, for the first time, at fixed temperatures. During temperature ramps, the kinetics exhibit distinct hysteresis. The melting occurs near the bulk melting point while the freezing is observed at much lower temperatures so that the undercooling interval is approximately 130 K. The time scale of the freezing kinetics measured at different fixed temperatures rapidly decreases as the latter are lowered. All these findings have been quantitatively described by assuming the nucleation to occur on the edges of nanoparticles and employing the classical nucleation theory with the corresponding modifications.
利用局域表面等离子体共振作为探针，我们研究了直径为 107nm、高度为 52nm 的固态和液态 Sn 纳米颗粒在温度斜坡和固定温度下的熔化和凝固动力学。这是首次在固定温度下进行此类研究。在温度斜坡过程中，动力学表现出明显的滞后现象。熔化发生在接近体熔化点附近，而凝固则发生在低得多的温度下，过冷区间约为 130K。在不同固定温度下测量的凝固动力学的时间尺度随着后者的降低而迅速减小。所有这些发现都通过假设形核发生在纳米颗粒的边缘，并采用经典形核理论并进行相应的修正来进行定量描述。
