TheE Dynamics of Formation and Evaporation of Mixed Alkali halide Nanocrystals: A Case of Comparable Lattice Energies

Abstract

The relative intensity distribution of the (Rb(n)K(14-n)I(13)(+) mixed nanocrystals containing a 'magic' number of 14 metal cations and 13 iodide anions is examined. These nanocrystals were generated through sputtering of mixed RbI/KI solids using fast atom bombardment, and analyzed by use of a double-focusing sector-field mass spectrometer. The relative intensities of the observed peaks is found to have a 'bimodal' distribution with a maximum near n=7. This observation is explained by assuming: (a) a rate of formation that is proportional to the number of isomers that can be formed for each mixed nanocrystal, and (b) a rate of dissociation that is insensitive to the composition of the mixed nanocrystal. The later assumption leads to the conclusion that the internal energies of these mixed nanocrystals are similar and independent of their composition. The conclusion is supported by the results of Monte Carlo simulation annealing as well as by the similarity of the known lattice energies of KI and RbI bulk crystals.

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Document Details

Document Type
Technical Report
Publication Date
Sep 21, 1994
Accession Number
ADA285052

Entities

People

  • Mostafa El-Sayed
  • Temer S. Ahmadi

Organizations

  • University of California, Los Angeles

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • California
  • Chemistry
  • Computational Science
  • Crystal Structure
  • Crystals
  • Dynamics
  • Electrons
  • Mass Spectra
  • Mass Spectrometers
  • Military Research
  • Monte Carlo Method
  • Physical Chemistry
  • Probability
  • Rate Of Formation
  • Simulations
  • Spectrometers
  • Sputtering

Readers

  • Combustion science or combustion engineering.
  • Materials Science and Engineering.
  • Molecular Photonics/Laser Physics