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Opis: In this work, three surfaces, namely, Mg(0001), Mg(10 ̄1 0) and Mg(11 ̄2 0) are investigated by means of Density Functional Theory and Generalized Gradient Approximation first-principle calculations. The surfaces have been characterized in terms of their interlayer distances, surface energies, Projected Density of States and Surface Core Level Shifts. Contrary to what was found in previous studies based on Density Functional Theory-Local Density Approximation, the use of Generalized Gradient Approximation exchange correlation functional unravels the oscillatory behavior of both interlayer distances and Surface Core Level Shifts of Mg(10 ̄1 0). Moreover, the Projected Density Of States of un-reconstructed Mg(11 ̄2 0) exhibit the typical quantisation of electronic levels associated to a 2D-confinement of a 3D nearly-free electron gas, as observed in nano-wires, and a Peierls instability along the unconfined direction. Different possible reconstructions on Mg(11 ̄2 0) have then been investigated. In particular, it is found that the surface energy of (2X1) and (3X1) reconstructions is almost degenerate and lower than the surface energy of the unreconstructed Mg(11 ̄2 0) surface. Because of the quasi-degeneracy of surface energies, Mg(11 ̄2 0) surface should be composed by a combination of all the quasi degenerate phases.
Najdeno v: osebi
Ključne besede: Density Functional Theory, first-principle calculations, Mg surface, Surface Core-Level Shift, surface relaxation, surface reconstruction
Objavljeno: 04.07.2017; Ogledov: 2995; Prenosov: 1979
Polno besedilo (1,77 MB)

Najdeno v: osebi
Ključne besede: zagotavljanje kakovosti, visoko šolstvo, univerza
Objavljeno: 05.02.2018; Ogledov: 1370; Prenosov: 0
Polno besedilo (2,90 MB)

Opis: The intriguing spatial variability of surface features on Krk Island has stimulated the research of this karst area located in the coastal zone of the Dinaric karst in Croatia. Field inspection, ortho-rectified aerial photos (0.5m resolution) and a topographic map (1:5,000) were used for the detection and delineation of detectable karst surface features appearing on the island with the area of 405.5 km². This method resulted in the identification of several yet undefined types of surface features occurring on karst, requiring the revision of the existing classification and re-establishment of a new classification system compatible with the particular field reality. Several morphologic and distributive parameters that had been calculated for each re-classified type of surface feature provided insight into the surface features elementary characteristics, their spatial variability and the correlation to the other types of surface features and to the recent karst relief. This analysis based on a large, accurate dataset, contributed to the general knowledge on karstic surface features, the conditions of surface features in Dinaric karst and to the understanding of the karst surface evolution on Krk Island.
Najdeno v: osebi
Ključne besede: karst geomorphology, GIS, spatial analysis, Krk Island, Dinaric karst, Adriatic Sea
Objavljeno: 13.09.2019; Ogledov: 1231; Prenosov: 79
Polno besedilo (17,12 MB)

Opis: Photoconductivity spectra measured in non-crystalline corannulene thin layers are compared to optical absorption in solution phase and thin films. The unexpected enhanced photoconductivity is correlated with GW–BSE theoretical predictions of corannulene gas-phase excitonic spectra. Theoretical analysis reveals a consistent contribution involving transitions to Super Atomic Molecular Orbitals (SAMOs), a unique set of diffuse orbitals typical of curved conjugated constructs. Results suggest SAMO population via direct photoexcitation as a potential mechanism towards exploiting these diffuse orbitals as conducting channels in suitably assembled quantum nanostructures or solids.
Najdeno v: osebi
Ključne besede: Coranulene, photoconductivity, thin layers, photoexcitation
Objavljeno: 26.09.2017; Ogledov: 1521; Prenosov: 111
Polno besedilo (644,91 KB)

Najdeno v: osebi
Ključne besede: thermoelectric properties, nanostructured porous silicon
Objavljeno: 01.12.2017; Ogledov: 1196; Prenosov: 0
Polno besedilo (1,14 MB)