中国物理B ›› 2016, Vol. 25 ›› Issue (3): 36102-036102.doi: 10.1088/1674-1056/25/3/036102
• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇 下一篇
Jin-Ping Zhang(张金平), Yang-Yang Zhang(张洋洋), Er-Ping Wang(王二萍), Cui-Ming Tang (唐翠明), Xin-Lu Cheng(程新路), Qiu-Hui Zhang(张秋慧)
Jin-Ping Zhang(张金平)1, Yang-Yang Zhang(张洋洋)1, Er-Ping Wang(王二萍)1, Cui-Ming Tang (唐翠明)2, Xin-Lu Cheng(程新路)2, Qiu-Hui Zhang(张秋慧)3
摘要: The thermal stability of Ti@Al core/shell nanoparticles with different sizes and components during continuous heating and cooling processes is examined by a molecular dynamics simulation with embedded atom method. The thermodynamic properties and structure evolution during continuous heating and cooling processes are investigated through the characterization of the potential energy, specific heat distribution, and radial distribution function (RDF). Our study shows that, for fixed Ti core size, the melting temperature decreases with Al shell thickness, while the crystallizing temperature and glass formation temperature increase with Al shell thickness. Diverse melting mechanisms have been discovered for different Ti core sized with fixed Al shell thickness nanoparticles. The melting temperature increases with the Ti core radius. The trend agrees well with the theoretical phase diagram of bimetallic nanoparticles. In addition, the glass phase formation of Al-Ti nanoparticles for the fast cooling rate of 12 K/ps, and the crystal phase formation for the low cooling rate of 0.15 K/ps. The icosahedron structure is formed in the frozen 4366 Al-Ti atoms for the low cooling rate.
中图分类号: (Structure of nanocrystals and nanoparticles ("colloidal" quantum dots but not gate-isolated embedded quantum dots))