Papers by Author: M. Davidović

Abstract: The calculations of the low-energy attachment cross section to metallic clusters are investigated. Low energy electrons are taken as slow enough to excite a giant dipole collective resonance within the cluster. The calculations are more refined than the earlier ones – they do not depend on the experimental data, and we improved RPAE calculation of the collective resonance in the cluster. The results are interesting for the nano-region and designing of new materials.

Abstract: Within the framework of the many-body theory by using the Random Phase Approximation with Exchange (RPAE) method we calculated the frequency dependent polarizability, refractive index, and Verdet coefficient of some atoms. Calculated time-dependent peculiarities of a set of atoms are very significant in the nano-region and might be important for designing new materials.

Abstract: In our previous work we investigated the conductivity and dielectric relaxation phenomena in heteropoly acids and their salts. In this work, we have studied the conductivity of grains and grain boundaries in compressed powders of 12-tungstophosphoric acid (WPA) salts with univalent and bivalent ions. The method of impedance spectroscopy has been employed in the frequency range from 5 Hz to 500 kHz. We obtained grains and grain boundaries conductivities as well as corresponding activation energies. Grain conductivity in all investigated salts is always higher than the grain boundary conductivity.