Pentagonal nanorods and nanoparticles with mismatched shell layers.

Nano-scale rods and particles having the axes of fivefold symmetry, i.e., pentagonal nanorods and nanoparticles, are theoretically and experimentally investigated. Such objects possess elastic strains and mechanical stresses. In the present research a new mechanism of stress relaxation in nanorods and nanoparticles is considered. The mechanism is implemented by a formation of a surface layer with crystal lattice mismatch. The elastic fields and energies for nanorods and nanoparticles with the mismatched layers are calculated in the framework of the disclination model. The optimal mismatch parameter giving the maximal energy release is determined. The threshold radius as the minimal radius of nanorods or nanoparticles for which the formation of the layer is energetically favorable, is found. The threshold radius is approximately 10 nm for nanoparticle and 100 nm for nanorod of typical FCC metal.

Analysis of broadband x-ray spectra of highly charged krypton from a microcalorimeter detector of an electron-beam ion trap.

Spectra of highly charged Kr ions, produced in an electron-beam ion trap (EBIT), have been recorded in a broad x-ray energy band (0.3 keV to 4 keV) with a microcalorimeter detector. Most of the spectral lines have been identified as transitions of B- to Al-like Kr. The transition energies have been determined with 0.2% uncertainty. A semi-empirical EBIT plasma model has been created to calculate a synthetic spectrum of highly charged Kr and to determine a charge state distribution of Kr ions inside the EBIT.