developed a method for the calculation of the electron-phonon coupling in the frame of the the density-functional and Hartree-Fock theory. It was found that the correct description of the hydrogen phonon states required the presence of the exact correlation term.
COBISS.SI-ID: 29049127
For the first time we report on a one-step synthesis and surface functionalization of dumbbell-like Au/Fe3O4 nano particles, which is a key step for their use as hybrid organic-inorganic nanotheranostic systems. The exact morphology of these dumbbell-like gold-iron oxide nanoparticles at the atomic scale was determined by high-resolution HAADF-STEM imaging. We were able to confirmed that the dumbbell-like gold-iron oxide nanoparticles were composed of gold particle with the fcc structure observed in [101]Au zone axis and cubic Fe3O4 with the inverse spinel structure, which was also observed in [101]Fe3O4 crystallographic projection. The interface between the Au and Fe3O4 crystal phase was manifested by the {111} faceted gold surface. The analysis of the crystallographic relationship between both structures indicates the epitaxial growth of Fe3O4 (111)Fe3O4 planes onto the (111)Au Au surface. The observed slight misalignment of gold and Fe3O4 crystal lattices was explained by the small lattice mismatch (~3%) between theoretical values of Au 2d111-(0.471 nm) and Fe3O4 d111(0.485 nm) values, which could provoke local structural compensation at the interface enabling the epitaxial growth of the Fe3O4 onto the surface of Au.
COBISS.SI-ID: 28708903
The second part of the investigation of the mechanism of topotaxial transformation of ilmenite to rutile and hematite was finished during the last year. First part of the investigation was studies of natural oriented rutile/hematite intergrowths, while in second part we tried to reproduce transformation of ilmenite single crystal to rutile and hematite during oxidation in air. Different conditions lead to different crystallographic orientation relationships between rutile and hematite in natural samples and ilmenite samples heated in air. The mechanism of transformation includes initial oxidation of Fe2+ in ilmenite to Fe3+ and its diffusion to the surface that triggers exsolution of Ti ions within the parent ilmenite structure to form rutile lamellae. The kinetics of diffusion controls the orientation relationships. However when the diffusion is slow, the cations have enough time to adopt the energetically most favourable positions and to form a tetragonally deformed rutile structure.
COBISS.SI-ID: 28374567
Encouraging testing results for hydrothermally synthesized TiO2 anataze coating, obtained within the BioTinet (FP7-ITN) project, led us toward further comprehensive analysis of the effect of the coating on their physico-chemical properties and their biological response. In collaboration with Biotechnical Faculty and Faculty for Mechanical Engineering, University of Ljubljana, we confirmed that the topographic characteristics have a more pronounced effect on bacterial attachment than the surface charge and wetting. By tailoring the coating surface, an attachment of bacteria as low as below 5% has been achieved. The importance of the obtained results has been reflected in a signed licence agreement for exploitation of secret knowledge with a foreign partner.
COBISS.SI-ID: 4496504
A modified electrophoretic deposition/infiltration of 3-dimensionally woven conductive fiber preform has been developed within the doctoral research of young scientist Aljaž Iveković. The technique enabled infiltration of 5 mm thick, 3-dimensionally woven, silicon cabride (SiC) fiber preform with aqueous suspension of SiC particles and thus a preparation of low-activation ceramic composite (SiCf/SiC) with significantly improved mechanical and thermal properties relevant for the use of the material under extreme conditions in fusion reactor.
COBISS.SI-ID: 28767527