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Povzetek: High-entropy alloys (HEAs) combine five or more elements in near-equiatomic ratios, opening an immense compositional space whose optical behaviour is still largely unknown. Phase-modulated ellipsometry on bulk CrMnFeCoNi (Cantor) shows that its intrinsic optical constants n, k, ε1, ε2 deviate strongly from the arithmetic mean of the constituent elements—by up to a factor of two beyond 1 µm—yet the derived functional responses, reflectance R and absorption coefficient α, are reproduced to within ~20 %. Cantor nanoparticles have been produced by nanosecond electric discharges in liquid nitrogen. Dark-field spectroscopy and Mie calculations reveal a dominant scattering mode near 100 nm that red-shifts and broadens with increasing size; the steady-state photothermal rise calculated from absorption cross-section σabs falls between those of the constituent pure metals.Generalising the averaging rule, we compute proxy values of R and α for 10 994 density-functional-theory-predicted HEAs. Successive optical, thermal and resource filters condense the space to 58 candidates at 355 nm and eight refractory alloys at 1064 nm, illustrating a “sustainable-by-design” route for future HEA photonics.
Ključne besede: high entropy alloys, optical properties
Objavljeno v DiRROS: 10.09.2026; Ogledov: 66; Prenosov: 41
Celotno besedilo (2,76 MB)
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Povzetek: The large-scale microwave plasma synthesis of graphene and nitrogen-doped graphene with tailored structural properties, crucial for their successful usage applications, has been demonstrated. The developed atmospheric pressure plasma method offers several advantages, including the continuous production of high-quality, free-standing graphene without the use of chemicals, solvents, catalysts, or additional heating. This non-toxic process eliminates the need for vacuum systems while achieving high temperatures. The method enables the precise control over graphene’s properties, such as the layer number, defects, sheet size, uniformity, and functionality, as well as the doping type and configuration, by adjusting the plasma parameters. Protocols for the synthesis of specific nanostructures with a controlled structural quality, production rate, and chemical composition have been established using methane and methylamine as precursors. The comprehensive physicochemical characterization of the graphene and nitrogen-doped graphene was carried out using scanning electron microscopy, high-resolution transmission electron microscopy, Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy.
Ključne besede: graphene, nitrogen-doped graphene, microwave plasma
Objavljeno v DiRROS: 10.09.2026; Ogledov: 57; Prenosov: 38
Celotno besedilo (4,22 MB)
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Povzetek: The increased demand for seafood, which accounts for 15% of global animal protein production, has inevitably raised the need for effective traceability systems to guarantee food safety and transparency, and to prevent overfishing and Illegal, Unreported and Unregulated activities (IUU). Such systems are essential for combating fraud and ensuring the correct development of the seafood market, enabling the exploitation of its nutritional and sustainable potential. Here, the current state of the art in technologies applied to seafood traceability is reviewed. The focus will be on three scientific approaches: stable isotope analysis, genetic markers, and fish-associated microbiota profiling, a novel approach that traces geographical origin based on unique bacterial communities. This study reviews the principles and application cases of these methods, emphasizing the advancements in these tools required to meet the growing demand for seafood.
Ključne besede: traceability, genetic markers, food fraud prevention
Objavljeno v DiRROS: 09.09.2026; Ogledov: 58; Prenosov: 42
Celotno besedilo (1,94 MB)
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Povzetek: Integrated electrochemical sensors (IESs) offer rapid and efficient detection of environmental pollutants, but their broader practical implementation requires overcoming common challenges associated with reproducible fabrication and long-term stability. In this work, these challenges were addressed using a thick-film approach to fabricate IESs with graphite-glass, glassy carbon, and carbon black working electrodes (WEs) by screen printing followed by firing at 850 °C. The relationship between the structure of the carbon-based WEs and the electrochemical performance of the IESs was systematically investigated using cyclic voltammetry (CV) in combination with X-ray powder diffraction, transmission electron microscopy (TEM), and scanning TEM. The analyses revealed distinct morphologies and structural ordering of the carbon WEs, which directly affect their electron-transfer kinetics, adsorption behaviour, capacitive response, and electrochemically active surface area. The ordered structure of the graphite-glass WE was associated with lower capacitance and faster electron-transfer kinetics, as determined from the CV response of the IES. In contrast, the disordered structure of the carbon black WE was associated with higher capacitance and slower kinetics of the IES. The glassy carbon-based IES exhibited kinetics similar to those of the carbon black-based IES, but with the lowest capacitance, resulting in the greatest signal definition. Consequently, although all IESs exhibited wide operating potential windows (−1.6 V to +1.0 V vs Ag/AgCl) and fast heterogeneous electron-transfer kinetics towards the [Fe(CN)6]3−/4− redox probe (7.6 × 10−3–15.5 × 10−3 cm s−1), the carbon materials differed in their electrochemical response and signal definition. Importantly, all IESs demonstrated excellent reproducibility (relative standard deviation < 2.4%), operational stability with less than 5% signal loss after 1000 CV cycles, and shelf-life stability exceeding 30 days. These findings demonstrate that tailoring the carbon structure of the screen-printed thick-film WEs enables reproducible fabrication of stable and reliable IESs while providing a versatile strategy for tuning their electrochemical performance towards application-specific requirements.
Ključne besede: graphite, glassy carbon, carbon black, screen-printed electrode, integrated electrochemical sensor, reproducibility, stability
Objavljeno v DiRROS: 09.09.2026; Ogledov: 53; Prenosov: 41
Celotno besedilo (5,11 MB)
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Povzetek: The discovery of ferroelectric nematic phase opened new directions in the field of soft matter chemistry and physics. In this paper, we have modified a previously reported ferroelectric nematogen based on molecular structure with dimethylamino-terminated part. We have prepared two new homologues by prolonging a side chain and investigated the effect of its length on the mesomorphic properties. While previously reported homologues exhibited a direct phase transition from the isotropic (Iso) to the ferroelectric nematic phase (NF), for prolonged alkyl chain there is a narrow nematic phase (N) in between. For new compounds, we have established their mesomorphic and material properties. We have confirmed ferroelectricity of the NF phase by the polarization, SHG signal and permittivity. Finally, we have compared these parameters with respect to the side-chain length and discussed new effects, discovered for prolonged homologues due to the presence of an additional N phase.
Ključne besede: ferroelectricity, nematic phase, nematogens
Objavljeno v DiRROS: 07.09.2026; Ogledov: 109; Prenosov: 138
Celotno besedilo (2,67 MB)
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