When the characteristic length scales get down to the nanometer regime, the phonon density of states (PDOS) deviates from the corresponding bulk structure. Although deviations of the PDOS from the corresponding bulk structure have been observed both in experiment and theory, still it is not well understood how various size effects change the PDOS. In this talk, I will present our work using molecular dynamic simulations to study the PDOS of different nano-structures like nanoparticles, nanocrystals, embedded nanoparticles and nanoglasses. I will show how the vibrational properties of each the nanostructures deviate significantly from those of single crystalline and bulk amorphous structures. This talk will illustrate a complete description of finite-size effects on the PDOS in terms of disorder, phonon confinement due to the particle, and surface stress.
When the characteristic length scales get down to the nanometer regime, the phonon density of states (PDOS) deviates from the corresponding bulk structure. Although deviations of the PDOS from the corresponding bulk structure have been observed both in experiment and theory, still it is not well understood how various size effects change the PDOS. In this talk, I will present our work using molecular dynamic simulations to study the PDOS of different nano-structures like nanoparticles, nanocrystals, embedded nanoparticles and nanoglasses. I will show how the vibrational properties of each the nanostructures deviate significantly from those of single crystalline and bulk amorphous structures. This talk will illustrate a complete description of finite-size effects on the PDOS in terms of disorder, phonon confinement due to the particle, and surface stress.
