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Lead telluride and germanium telluride are well-known IV-VI semiconductors, which is now the focus of research due to the perspective of application as thermoelectrics for midrange temperatures. Solid solutions and heterostructures on this basis, obtained by molecular beam epitaxy, are a promising direction for the development of these materials. In this paper, we have focused on the Raman spectra excited by the 514.5 nm laser line (out of resonance) of PbTe, GeTe, (Pb, Ge)Te, and (Pb, Ge, Eu)Te layers grown on BaF2 (111) monocrystalline substrates. The obtained phonon properties are related to the properties of the corresponding bulk materials or can be explained by a model that takes into account the difference in the masses of the constituent elements only, as is the case with the local mode of Ge in PbTe (registered at about 181 cm−1). Multiphonon processes registered for this phonon are a consequence of the change in the electronic structure of PbTe and electron-phonon interaction. An improvement in the quality of thin films due to doping with Eu ions was also registered.

Properties of CdS thin films were investigated applying atomic force microscopy (AFM) and Raman spectroscopy. CdS thin films were prepared by using thermal evaporation technique under base pressure 2 x 10-5 torr. The quality of these films was investigated by AFM spectroscopy. We apply Raman scattering to investigate optical properties of CdS thin films, and reveal existence of surface optical phonon (SOP) mode at 297 cm-1. Effective permittivity of mixture were modeled by Maxwell - Garnet approximation.

Our work deals with the problem of producing a complex metal-ceramic composite using the processes of internal oxidation (IO) and severe plastic deformation. For this purpose, Cu-Al alloy with 0.4wt.% of Al was used. IO of sample serves in the first step of the processing as a means for attaining a fine dispersion of nanosized oxide particles in the metal matrix. Production technology continues with repeated application of severe plastic deformation (SPD) of the resulting metalmatrix composite to produce the bulk nanoscaled structural material. SPD was carried out with equal channel angular pressing (ECAP), which allowed that the material could be subjected to an intense plastic strain through simple shear. Microstructural characteristics of one phase and multiphase material was studied on internally oxidized Cu with 0.4wt.% of Al sample composed of one phase copper-aluminum solid solution in the core and fine dispersed oxide particles in the same matrix in the mantle region. In this manner AFM, X-ray diffraction and Raman spectroscopy were used. Local structures in plastically deformed samples reflect presence of Cu, CuO, Cu2O, Cu4O3 or Al2O3 structural characteristics, depending on type of sample.

Background/Objectives: Syncope is a common clinical problem often requiring pharmacological treatment, yet evidence-based therapies remain limited. Midodrine, a vasopressor agent, is frequently used, though its autonomic effects over time remain unclear. This study aimed to assess autonomic nervous system changes and blood pressure response in syncope patients treated with Midodrine, placebo, or their combination. Additionally, the structural properties of the Midodrine placebo were analyzed using nanotechnological methods. Methods: A total of 67 patients with syncope were randomized to receive Midodrine, sucrose placebo, or their combination over three weeks. All participants underwent 24 h Holter ECG with heart rate variability (HRV) analysis and ambulatory blood pressure monitoring before and after therapy. Structural analysis of Midodrine tablets, sucrose, and Midodrine placebo was performed using Raman spectroscopy and X-ray diffraction (XRD). Results: Patients receiving the Midodrine–placebo combination showed a significant reduction in HRV markers of parasympathetic activity (RMSSD, pNN50, HF) and an increase in sympathetic dominance (LF/HF ratio) compared to the other groups. Only this group showed a statistically significant rise in average systolic and diastolic blood pressure. Raman and XRD analyses revealed structural alterations in the sucrose-based placebo compared to its original form, indicating subtle changes in crystalline structure. Conclusions: In this exploratory study, the combination of Midodrine and placebo was associated with autonomic imbalance and modest increases in blood pressure, which may indicate a potential effect in patients with hypotensive syncope phenotypes. These preliminary findings should be interpreted with caution, and the structural modifications observed in the placebo formulation are presented as hypotheses requiring further investigation rather than established mechanisms.

We present new aspects of erbium- or ytterbium-doped pure gadolinium oxide (Gd 2 O 3 :Er 3+ /Yb 3+ ) as a suitable candidate for drug delivery and magnetic resonance (MR) applications. The samples were prepared using the conventional sol–gel synthesis technique. The structural studies revealed that the prepared sample was monophased and crystallizes in a cubic structure. FTIR measurements confirmed the creation of Gd 2 O 3 :Er 3+ /Yb 3+ phosphor. SEM micrographs clearly indicated that the particles crystallized in uniform shape, exhibiting nano-rod formation, with the particle size ranging from 55 to 5 nm. TEM images revealed that Er 3+ - and Yb 3+ -co-doped Gd 2 O 3 nanoparticles were the collection of the nano-rods 2–4 nm thick and 18–20 nm long. Also, photoluminescence analysis of the phosphor samples for variable concentrations of doping ions was presented. When doped with Er 3+ /Yb 3+ , nano-rod Gd 2 O 3 emits intense green emission and some red emission peaks, under a 980-nm near-infrared laser. Our study shows that as-prepared samples may be useful for optical imaging systems and that nano-rod formation may be used as a major host carrier for drug delivery.

The paper presents the extended results of structural investigations of Pb 0.9 Mn 0.1 Te, and Pb 0.9 Mn 0.1 Te systems doped with In (2 at.%) and Ga (4 at.%) by means of EXAFS (extended X-ray absorption fine structure) technique. EXAFS measurements performed at Te–, Mn–, In– and Ga–K absorption edges at different temperatures are complemented with X-ray diffraction, flame absorption and X-ray fluorescence analysis. That way the complete information about elemental concentration; crystal structure; local environment around constitutive and impurity atoms (including their displacements from the regular lattice positions); local and long-range ordering; and the overall influence of doping on the host crystal structure is derived. The obtained results represent an important step towards understanding the structural aspects of doping of lead telluride-based semiconductors with Mn and group III elements and their connection to electronic and optical phenomena important for their applications.

Structural aspects of Cr and Ni incorporation into the PbTe lattice are studied by means of Extended X-ray Absorption Fine Structure (EXAFS). EXAFS measurements enabled to get exact information on Pb and Te local structural features and their thermal evolution. The obtained results also revealed that by distorting their local environment, impurity atoms (Cr, Ni) add to high inherent disorder already present in the host PbTe. Larger anharmonicity of the Pb–Te bond and larger atomic thermal parameters observed in PbTe(Cr, Ni) could be of interest for thermoelectronics applications since they are both expected to reduce the thermal conductivity.