Significant results of scientific activity in year 2014

Polycyclic aromatic hydrocarbons appear among the most abundant observed species in interstellar space and are key molecules to understanding the prebiotic roots of life. However, their existence and abundance in space remain a puzzle. We have shown that aromatic species can be efficiently formed on the graphitized surface of the abundant silicon carbide stardust on exposure to atomic hydrogen under pressure and temperature conditions analogous to those of the interstellar medium, mimicked here.

Characteristic frequencies of nanoscale polar fluctuations have been resolved by means of neutron diffuse scattering measurements on a Sr_0,61Ba_0,39Nb₂O₆ single crystal in the MHz-GHz frequency region. Comparison with dielectric measurements proved that these polar fluctuations are a source of giant dielectric response, whose temperature-frequency dependence is specific for a significant group of substances exhibiting a glass-type ferroelectric phase transition, so-called relaxor ferroelectrics.

State-of-the-art laser systems are able to generate ionising radiation of significantly high energies by focusing ultra-short and intense pulses onto targets. Thus, measures ensuring the radiation protection of both working personnel and the general public are required. However, commercially available dosemeters are primarily designed for measurement in continuous fields. Therefore, it is important to explore their response to very short pulses.

Crystallographic analysis showed that {1 0 1 2} twinning is the main deformation mechanism during compression. Twin-free microstructure, stress–strain curve, measured microtextures and macroscopic sample dimensions proved that reversible motion of twin boundaries („de-twinning“) occurs during subsequent compression along the normal direction which is more favourable than nucleation of new {1 0 1 2} twins during this compression thus profiling magnesium alloys to be rather smart materials.