TheE Dynamics of Formation and Evaporation of Mixed Alkali halide Nanocrystals: A Case of Comparable Lattice Energies
CALIFORNIA UNIV LOS ANGELES DEPT OF CHEMISTRY AND BIOCHEMISTRY
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The relative intensity distribution of the RbnK14-nI13 mixed nanocrystals containing a magic number of 14 metal cations and 13 iodide anions is examined. These nanocrystals were generated through sputtering of mixed RbIKI 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 n7. 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.
- Inorganic Chemistry
- Physical Chemistry