Electron diffraction data on structural transformations in free clucters of argon

Supersonic-jet luminescence spectroscopy was applied to study vibronic transitions in icosahedral N2 and Ar-N2 clusters having from 100 to 400 particles per cluster. In the case of mixed Ar-N2 clusters, the w->X transitions were observed to occur in single N2 molecules in an Ar environment, that is very much in the same way as in Ar-N2 bulk samples. In N2 clusters, however, a band series was detected which was never observed earlier. In the spectra of Ar-N2 clusters, this new...

Luminescence of surface and free bulk excitons is detected in xenon for the first time for substrate-free rare-gas clusters. Xenon clusters were produced by the method of gas condensation in a supersonic jet emitted into vacuum. Optical study was accompanied by electron diffraction measurements to determine the structure of clusters.

The time-dependent kinetics of formation and evolution of nano-size atomic clusters is investigated and illustrated with the nucleation dynamics of ion-seed Ar$_n$H$^+$ particles. The rates of growth and degradation of Ar-atomic shells around the seed ion are inferred from Molecular Dynamics (MD) simulations. Simulations of cluster formation have been performed with accurate quantum-mechanical binary interaction potentials. Both the nonequilibrium and equilibrium growth of Ar...

We employ force-field molecular dynamics simulations to investigate the kinetics of nucleation to new liquid or solid phases in a dense gas of particles, seeded with ions. We use precise atomic pair interactions, with physically correct long-range behavior, between argon atoms and protons. Time-dependence of molecular cluster formation is analyzed at different proton concentration, temperature and argon gas density. The modified phase transitions with proton seeding of the ar...

The advantages of convergent beam electron diffraction for symmetry determination at the scale of a few nm are well known. In practice, the approach is often limited due to the restriction on the angular range of the electron beam imposed by the small Bragg angle for high energy electron diffraction, i.e. a large convergence angle of the incident beam results in overlapping information in the diffraction pattern. Techniques have been generally available since the 1980s which ...

A continuous cryogenic hydrogen cluster-jet target has been developed for laser-plasma interaction studies, in particular as a source for the acceleration of protons. Major advantages of the cluster-jet target are the compatibility with pulsed high repetition lasers and the absence of debris. The cluster-jet target was characterized using the Mie-scattering technique allowing to determine the cluster size and to compare it with an empirical prediction. In addition, an estimat...

Cathodoluminescence VUV spectra of free pure nitrogen clusters produced by condensation of gas mixtures in supersonic jets expanding into vacuum were studied. The clusters were of icosahedral structure, as evidenced by our electron diffraction measurements, i.e., quasicrystals, and contained about 1000 atoms. The cluster temperature was about 40 K. The luminescence spectra measured in the range of 45,000-75,000 cm^-1 clearly showed three vibronic w -> X series of transitions ...

We have recorded the coherent diffraction images of individual xenon clusters with intense extreme ultraviolet pulses to elucidate the influence of light-induced electronic changes on the diffraction pattern. Using the FLASH free-electron laser we tuned the wavelength to specific xenon atomic and ionic resonances. The data show the emergence of a transient core-shell structure within the otherwise homogeneous sample. Simulations indicate that ionization and nanoplasma formati...

This paper has been withdrawn by the author(s), due to technical copyright problems with the Royal Society of Chemistry.

Physical mechanisms of structural transformations in deposited metallic clusters exposed to an electron beam of a transmission electron microscope (TEM) are studied theoretically and computationally. Recent TEM experiments with size-selected Au$_{923}$ clusters softly deposited on a carbon substrate showed that the clusters undergo structural transformations from icosahedron to decahedron and face-center cubic (fcc) structures upon exposure to a 200-keV electron beam. In this...