摘要
从Hill微系统热力学理论出发,根据已建立的金属纳米晶体结合能的等效模型与相应熔化热力学模型,建立了简单、实用的金属纳米晶体熔化与过热的等效模型.模型不仅预测了随表面原子百分数的增大自由表面纳米晶体熔点与熔化熵的减少及包覆纳米晶体熔点与熔化熵的增加,还对纳米晶体产生过冷和过热的条件进行了分析.对金属纳米微粒、纳米线及纳米薄膜的熔点、熔化熵增大或减少的预测值与实验结果相一致.
A simple but practical model for the melting and superheating of metallic nanocrystals was presented on the basis of Hill thermodynamic theory for small systems and our equivalent model for cohesive energy and corresponding melting thermodynamics. The model predicts that with increasing surface-to-volume atomic ratio, the melting temperature and melting entropy of free-standing nanocrystals will decrease while the above two parameters for the embedded nanocrystals will increase, and the conditions of supercooling and superheating of nanocrystals are discussed as well. The theoretical predictions on the variations of the above two parameters of metallic nanoparticles, nanowires and nanofilms are in agreement with the present experimental results.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2005年第5期458-462,共5页
Acta Metallurgica Sinica
基金
国家自然科学基金资助项目50401010
关键词
金属纳米晶体
熔化
过热
metallic nanocrystal
melting
superheating
