The growth and phase formation features, along with the influence of structure and morphology on the electronic, optical, and transport properties of Cr₂GeC and Cr_2-xMn_xGeC MAX phase thin films synthesized by magnetron sputtering technique, were studied. It was found that the Cr:Ge:C atomic ratios most likely play the main role in the formation of a thin film of the MAX phase. A slight excess of carbon and manganese doping significantly improved the phase composition of the films. Cr₂GeC films with a thicknesses exceeding 40 nm consisted of crystallites with well-developed facets, exhibiting metallic optical and transport properties. The hopping conduction observed in the Cr_2-xMn_xGeC film could be attributed to the columnar form of crystallites. Calculations based on a two-band model indicated high carrier concentrations N, P and mobility μ in the best-synthesized Cr₂GeC film, suggesting transport properties close to single crystal material. The findings of this study can be utilized to enhance the growth technology of MAX phase thin films.

A series of single crystals of Ni_3−xCo_xB₂O₆ compounds with the kotoite structure and with different concentrations of transition metal ions (x = 0; 0.19; 0.6; 0.93 and 2) were obtained.

Magnetic nanoparticles, consisting of a metallic iron core with a shell of gold and iron oxides, were synthesized by ultra-high vacuum surface nucleation on a water-soluble NaCl substrate followed by oxidation in water. Using the methods of electron microscopy, electron diffraction, photoelectron spectroscopy and calculation of the specific density of iron in the oxidized shell, the oxides γ-Fe₂O₃, Fe₃O₄ and oxyhydroxide α-FeO(OH) were discovered. A non-uniform distribution of the Fe³⁺/Fe²⁺ ion ratio over the particle depth and a predominance of α-FeO(OH) in the contrast shell of nanoparticles, directly observed in transmission electron microscopy, were discovered. Comparison of the magnetic properties of partially gold-coated particles with similar Fe particles without gold showed a larger residual volume of unoxidized metal core with partial gold coating. This points to the anisotropy of the surface chemical properties associated with the Janus-like structure. For the first time, the magnetodynamic properties of partially gold-coated Fe nanoparticles were assessed by ellipsometric measurements of the surface of a colloidal solution in a gradient magnetic field.

Gold nanoparticles (AuNPs) exhibit unique optical properties due to localized surface plasmon resonance (LSPR), making them valuable for applications in nanophotonics, sensing, and biomedicine. This study investigates the formation of ordered AuNP monolayers on Au/Si(100) substrates with controlled roughness prepared by magnetron sputtering and thermal evaporation. We examine how substrate morphology influences nanoparticle organization and analyze collective optical properties using reflection spectroscopy. Ordered AuNP ensembles were formed at the air/water interface and transferred onto Au/Si(100) substrates. Our results demonstrate that substrate roughness significantly affects monolayer packing density and uniformity. Reflection spectra revealed two characteristic resonances: an LSPR peak at ~525 nm and a low-energy resonance at ~800 nm associated with collective particle-substrate interactions. Significantly, encapsulation with cetyltrimethylammonium chloride (CTAC) molecules suppressed the long-wavelength resonance. Comparative analysis with colloidal AuNP dimers suggests charge-mediated interactions in plasmon resonance formation. These findings demonstrate effective control of collective plasmonic modes through substrate morphology tuning and nanoparticle surface functionalization, offering promising avenues for developing advanced optical materials and sensor platforms.