Computer study of the temperature dependence of physical properties of noncrystalline silicon nanoparticles

• Published in: Surface investigation, x-ray, synchrotron and neutron techniques x-ray, synchrotron and neutron techniques, 2007-06, Vol.1 (3), p.286-293
• Main Authors: Galashev, A. E., Izmodenov, I. A., Novruzova, O. A., Novruzov, A. N.
• Format: Article
• Language: English
• Subjects: Bulk density; Heating; Molecular dynamics; Nanoparticles; Physical properties; Potential energy; Silicon; Temperature dependence
• ISSN: 1027-4510; 1819-7094
• DOI: 10.1134/S102745100703010X

Variations in the structure and kinetic properties of vitreous and amorphous Si400 nanoparticles upon heating from 300 to 1700 K are studied by molecular dynamics. The nanoparticle density increases with temperature and approaches the density of bulk solid silicon. A transition from a unimodal to a bimodal distribution of bond lengths is observed upon heating. This transition is more pronounced in the case of the vitreous nanoparticle. The average bond length in the amorphous nanoparticle is, as a rule, larger than that in the vitreous one, and the average number of bonds per atom is lower than that in the vitreous nanoparticle for nearly all studied temperatures. Negative values of the excess potential energy correspond to middle concentric layers of nanoparticles. Liquid layers form in the surface region of nanoparticles in the vicinity of the melting transition. A kinetic test indicating the beginning of nanoparticle melting is formulated.