Recent Submissions

Now showing 1 - 3 of 3
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    Morphological features in aluminum nitride epilayers prepared by magnetron sputtering
    (De Gruyter Open, 2015-01-01) Stach, Sebastian; Sobola, Dinara; Talu, Stefan; Kaspar, Pavel; Tománek, Pavel; Giovanzana, Stefano; Grmela, Lubomír
    The aim of this study is to characterize the surface topography of aluminum nitride (AlN) epilayers prepared by magnetron sputtering using the surface statistical parameters, according to ISO 25178-2:2012. To understand the effect of temperature on the epilayer structure, the surface topography was investigated through atomic force microscopy (AFM). AFM data and analysis of surface statistical parameters indicated the dependence of morphology of the epilayers on their growth conditions. The surface statistical parameters provide important information about surface texture and are useful for manufacturers in developing AlN thin films with improved surface characteristics. These results are also important for understanding the nanoscale phenomena at the contacts between rough surfaces, such as the area of contact, the interfacial separation, and the adhesive and frictional properties.
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    Characterization of the native oxide on CdTe surfaces
    (Sciendo, 2019-05-29) Sobola, Dinara; Kaspar, Pavel; Nebojsa, Alois; Hemzal, Dušan; Grmela, Lubomír; Smith, Steve J.
    This study focuses on the description of oxidation of CdTe monocrystal surfaces after selective chemical etching. Measurements of surface morphology of the oxides occurring in short time are valuable for deeper understanding of the material degradation and fabrication of reliable devices with enhanced performance. The samples with (1 1 1) orientation were selectively etched and cleaned of oxide. Exposure of the oxide-free surfaces of CdTe to air at normal atmospheric conditions over 24 hours leads to an appearance of characteristic surface features. The oxidized surfaces were investigated by scanning electron microscopy, scanning probe microscopy, Raman spectroscopy and ellipsometry. The results indicate clear differences in the oxidation of Cd-terminated and Te-terminated surfaces.
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    Characterization of nanoblisters on HOPG surface
    (De Gruyter OPEN, 2019-08-07) Sobola, Dinara; Papež, Nikola; Dallaev, Rashid; Ramazanov, Shihgasan; Hemzal, Dušan; Holcman, Vladimír
    We report on influence of the surface functionalization on the properties of highly oriented pyrolytic graphite. The samples were processed in nitric acid and characterized by XPS, Raman and EDX spectroscopies, AFM, SEM and optical microscopy. It is shown that interaction of nitric acid with the surface of HOPG leads to two types of reactions: oxidation of the graphite and intercalation of the nitrate ions at the blistered areas.