Structures and Properties of Nanometer Size Materials III. Structures and Physical Properties of Iron Nanoparticles

✍ Scribed by Li Xiao-Hua; Ma Mei-Hua; Huang Jin-Fan

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 175 KB
• Volume: 23
• Category: Article
• ISSN: 0256-7660
• DOI: 10.1002/cjoc.200590693

✦ Synopsis

Abstract

Molecular dynamics computer simulation has been carried out to study the structure and physical properties of iron nanoparticles with 331 to 2133 Fe atoms or with diameter from 2.3 to 4.3 nm. The core of liquid nanodroplets has the similar structure of the bulk molten iron liquid that has an average coordination number around 10.5 and the packing density around 0.45, although the closest FeFe distance is slightly longer in the bulk liquid. Most of the iron nanoparticles formed from the cooling of molten nanodroplets have the same body center cubic crystal structure as it was observed in the bulk under the normal temperature and pressure. Lattice contraction was observed for iron nanoparticles. An amorphous solid and an HCP like solid were obtained accidentally during the quenching runs on Fe~331~ nanoparticles. The physical properties of iron nanoparticles such as molar volume, density, thermal expansion coefficient, melting point, heat of fusion, heat capacity and diffusion coefficient were estimated based on the results obtained from this simulation. The dependence of physical properties on the nanoparticle sizes was addressed.