Melting Temperature, Brillouin Shift, and Density of States of Nanocrystals

• Published in: Nano letters Vol. 2; no. 5; pp. 519 - 523
• Main Author: Shrivastava, Keshav N
• Format: Journal Article
• Language: English
• Published: American Chemical Society 01-05-2002
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl020287t

The amplitude of displacement of atoms due to scattering at the surface is calculated. It is found that the zero-point vibrational correction to the mean-square displacement varies as the inverse square of the nanocrystal size and the temperature-dependent part also varies with the nanocrystal size. The melting temperature is found to depend on the nanocrystal size so that smaller melting temperature is obtained for smaller nanocrystals. The phonon−phonon scattering is found to shift the Brillouin line such that as the crystal size reduces, it moves toward the Rayleigh line. The phonon density of states is found to be larger for nanocrystals than for the bulk crystals as it depends on the inverse square of the nanocrystal size.