In the present paper, V₂O₅-TeO₂ glass was prepared by the melt-quenching technique. Crystallization of glass with a vanadium content higher than 35%mol results in an increase in electrical conductivity by a few orders of magnitude and a decrease in activation energy from ~0.40 to ~0.12 eV. In this work, a critical review of existing charge transfer models was presented on the example of V₂O₅-TeO₂ glass and glass–ceramics. Schnakenberg’s and Friedman-Triberis’ charge transfer models were found to be applicable to both glass and glass–ceramics. Optical phonon frequencies obtained from Schnakenberg’s model are in agreement with FTIR studies. Values of activation energies obtained from the Schnakenberg model decrease after crystallization. Friedman-Triberis’ model shows an increase in the density of states near the Fermi level from 10¹⁹ eV⁻¹ cm⁻³ in glass, to 10²¹ eV⁻¹ cm⁻³ in glass ceramics. Structural studies show that the main crystallizing phase is Te₂V₂O₉ which occurs with the V₂O₅ shell in glasses with compositions 50–50%mol and 45–55%mol. It is concluded that crystallization results in the reduction of vanadium ions in the remaining glass matrix which leads to an increase in the V⁴⁺/V⁵⁺ ratio and therefore, an increase in electrical conductivity.

The disintegration of a continuous metallic thin film leads to the formation of isolated islands, which can be used for the preparation of plasmonic structures. The transformation mechanism is driven by a thermally accelerated diffusion that leads to the minimalization of surface free energy in the system. In this paper, we report the results of our study on the disintegration of gold thin film and the formation of nanoislands on silicon substrates, both pure and with native silicon dioxide film. To study the processes leading to the formation of gold nanostructures and to investigate the effect of the oxide layer on silicon diffusion, metallic film with a thickness of 3 nm was deposited by molecular beam epitaxy (MBE) technique on both pure and oxidized silicon substrates. Transformation of the thin film was observed by low-energy electron microscopy (LEEM) and a scanning electron microscope (SEM), while the nanostructures formed were observed by atomic force microscope (AFM) method. Structural investigations were performed by low-energy electron diffraction (LEED) and X-ray photoelectron spectroscopy (XPS) methods. Our experiments confirmed a strong correlation between the formation of nanoislands and the presence of native oxide on silicon substrates.

Sol–gel layers have been the subject of many studies in recent decades. However, very little information exists about layers in which carbon structures are developed in situ. Using the spin-coating method, we obtained thin iron-doped SiO₂/C composite films. The results of Raman spectroscopy showed that our samples consisted of graphitic forms and polymers. The latter’s contribution decreases with rising temperature. FTIR and EDS studies show changes in carbon distribution on top of the layer, depending on the sintering temperature. The samples sintered at 800 °C showed a significant increase in the contribution of carbon forms to the layer’s surface. Therefore, high conductivity can be observed in this sample. The results of XPS spectroscopy showed that the contribution of sp³ hybridized carbon increases after etching. The total electrical conductivity, studied by a DC four-wire technique, increased with the temperature and showed almost linear characteristics with significant changes below 150 K. The reduced activation energy plot has a positive temperature coefficient, which is a characteristic property of the conductive polymers in a metallic regime of conductivity.

V₂O₅–TeO₂ glass–ceramics (VTGC) were prepared by controlled annealing of the V₂O₅–TeO₂ glass (VTG), which illustrates a parent glass matrix with a single charge carrier. The annealing proceeded at six temperatures selected between the glass transition and the maximum of the first crystallization process to obtain various nanocrystallite sizes. Heat treatment caused an increase in DC conductivity by 2.5–3.5 (250–285 °C) order of magnitude. Using thermal analysis, the crystal growth process was determined to be 1D. Structural studies show that the obtained materials are partially amorphous and polycrystalline with nanometer-sized crystallites. Subtle thread-like structures were observed using conductive AFM. The activation energy of the conduction process decreased from 0.38 eV in VTG to 0.18–0.11 eV (250–285 °C) in VTGC. The radii of crystallites were calculated based on the theoretical model of electron hopping between connected semiconducting nanocrystallites and vary between 1.7 and 2.8 nm (250–285 °C). Thermoelectric studies indicate constant carrier concentration. Features characteristic of small polaron hopping-governed materials were observed. We suggest V₃O₇ nanocrystals as conductive media in VTGC. Graphical abstract

In this work, a cost-effective method for fabricating silver–platinum nanoalloys through thermally activated dewetting of thin metallic films is demonstrated. Ag and Pt bilayers with a total thickness of 8 nm were deposited using DC magnetron sputtering, followed by annealing at 650 °C under an argon atmosphere. The process induced the transformation of continuous bilayers into isolated nanoislands through solid-state dewetting. Scanning electron microscopy and transmission electron microscopy analyses revealed the formation of well-defined, nearly spherical nanoislands with a homogeneous elemental distribution, as measured by energy dispersive spectroscopy. Additionally, X-ray photoelectron spectroscopy measurements confirmed the coexistence of both metals in metallic states, with a slight Ag deficiency attributed to its higher instability and desorption during the annealing process. Optical measurements revealed the presence of a single resonance peak. The composition-dependent plasmonic resonance band was observed for low Pt contents, while progressively blue-shifting and decreasing in intensity with increasing Pt concentration. This behavior is consistent with the strong d-electron contribution of platinum, which suppresses plasmonic oscillations. The obtained results demonstrate that thermally activated dewetting enables the synthesis of homogeneous Ag–Pt nanoalloys at the nanoscale, both in volume and on the surface of nanostructures, overcoming miscibility limitations of the bulk Ag–Pt system, and provide insight into their structure–property relationships relevant for catalytic and plasmonic applications.