Atomic vibrations in iron nanoclusters: Nuclear resonant inelastic x-ray scattering and molecular dynamics simulations
Abbreviated Journal Title
Phys. Rev. B
DENSITY-OF-STATES; SYNCHROTRON-RADIATION; PHONONS; CLUSTERS; SURFACES; NICKEL; Physics, Condensed Matter
The lattice vibrational dynamics of supported, self-assembled, isolated (57)Fe nanoclusters was studied by nuclear resonant inelastic x-ray scattering and molecular dynamics calculations. The morphological and structural properties and the chemical state of the experimental nanoclusters were investigated by atomic force microscopy, high resolution transmission electron microscopy, and x-ray photoelectron spectroscopy. The measured and calculated vibrational densities of states (VDOSs) reveal an enhancement of the low- and high-energy phonon modes and provide experimental and theoretical proof of non-Debye-like behavior in the low-energy region of the VDOS. Experimentally, this effect was found to depend on the nature of the surface shell (oxide or carbide) of the core/shell nanoclusters. According to the calculations for supported isolated pure Fe nanoclusters, the non-Debye-like behavior appears not only in the surface shell but also in the bcc-Fe core of the nanocluster due to the hybridization of surface and bulk modes.
Physical Review B
"Atomic vibrations in iron nanoclusters: Nuclear resonant inelastic x-ray scattering and molecular dynamics simulations" (2007). Faculty Bibliography 2000s. 6992.