Molecular dynamics simulations incorporating an analytic embedded atom potential have been used to investigate the atomic structure and surface order of the Al vicinal surfaces for the temperature up to 900 K. The relaxation, mean square vibrational amplitude, and structure factor as a function of temperature, and of the terrace width for the p(100) (111) surfaces (2 p 10) are discussed. The obtained structure factor indicates that the anharmonic effect reduces with increasing terrace widths. The decrease of surface energy with increasing terrace width also supports this conclusion.

The analytic embedded atom method (EAM) type many-body potentials of hcp rare earth metals (Dy, Er, Gd, Ho, Nd, Pr, and Tb) have been constructed. The hcp lattice is shown to be energetically most stable when compared with the fcc and bcc structure, and the hcp lattice with ideal c/a. The mechanical stability of the corresponding hcp lattice with respect to large change of density and c/a ratio is examined. The phonon spectra, stacking fault and surface energy are calculated. The activation energy for vacancy diffusion in these metals has been calculated and the most possible diffusion paths are predicted. Finally, the self-interstitial atom (SIA) formation energy and volume have been evaluated for eight possible sites. This calculation suggests that the crowdion and basal split are the most stable configurations. The SIA formation energy increases linearly with the increase of the melting temperature.

Acoustic-phonon transmission and thermal conductance in a double-bend quantum waveguide at low temperatures are investigated with the use of the scattering matrix method. The calculated results show that the total transmission coefficient versus the reduced phonon frequency exhibits a series of resonant peaks and dips. The stop-frequency gap can be observed for certain structural parameters due to the mode-mode coupling in the bend region. The universal quantum thermal conductance and the decrease of the thermal conductance at very low temperatures can be clearly observed. However, for higher temperatures where the higher transverse modes are excited, the reduced thermal conductance K/T is proportional to temperature T. The transmission coefficient and thermal conductance sensitively depend on the geometric parameters of the double bend, which provide an efficient way to control thermal conductance artificially by adjusting the parameters of the proposed microstructures.

In the present paper, the size and temperature effects on lattice distortion of Ag and Pt nanoparticles have been investigated in terms of atomic mean bond length using the molecular dynamics simulations and the modified analytic embedded atom method. It is found that the lattice contraction ratio decreases linearly with the reciprocal of the particle size. The average value of lattice contraction over the whole system is larger than that of the experimental data, and the average value of lattice contraction in the inner core has a better agreement with the experiment results. This phenomenon is mainly resulted by inhomogeneous lattice distortion. The surface distortion and the size effect on the inner core distortion are remarkable. As the grain size increases to a certain degree, the inhomogeneous surface lattice distortion is mainly localized to the outer shell with a thickness of 2-3 lattice parameters.