Loading...

Effects of particle size, shape and crystal structure on the formation energy of Schottky vacancies in free-standing metal nanoparticles: A model study

Delavari H., H ; Sharif University of Technology | 2011

1118 Viewed
  1. Type of Document: Article
  2. DOI: 10.1016/j.physb.2011.06.051
  3. Publisher: 2011
  4. Abstract:
  5. A simplified model based on cohesive energy is proposed to estimate the formation energy of Schottky vacancies (VFE) in free-standing metal nanoparticles with BCC and FCC crystal structures. To study the effect of particle size and shape, the surface energy, elastic contraction and average coordination number of particles at the surface and core was considered. It is shown that the energy of vacancy formation in FCC nanoparticles increases with decreasing the size while the effect of particle shape (sphere, cubic and icosahedral) is marginal. In spite of this behavior, BCC nanoparticles exhibit a critical particle size at around 25 Å, at which a minimum VFE is attained. Additionally, the energy of vacancy formation is notably lower for BCC nanoparticles with cubic shape than spherical ones. The application of the developed model is shown for free-standing Fe and Cu nanoparticles
  6. Keywords:
  7. Modeling ; Vacancy ; Average coordination number ; Cohesive ; Cohesive energies ; Critical particle size ; Cu nanoparticles ; Cubic shape ; Developed model ; Formation energies ; Metal nanoparticles ; Model study ; Particle shape ; Particle size and shape ; Schottky ; Simplified models ; Vacancy formation ; Nanoparticles ; Particle size ; Spheres ; Surface chemistry ; Vacancies ; Crystal structure
  8. Source: Physica B: Condensed Matter ; Volume 406, Issue 20 , October , 2011 , Pages 3777-3780 ; 09214526 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0921452611006144