Nitrogen-vacancy color centers in diamond are a very promising medium for many sensing applications such as magnetometry and thermometry. In this work, we study nanodiamonds deposited from a suspension onto glass substrates. Fluorescence and optically detected magnetic resonance spectra recorded with the dried-out nanodiamond ensembles are presented and a suitable scheme for tracking the magnetic-field value using a continuous poly-crystalline spectrum is introduced. Lastly, we demonstrate a remote-sensing capability of the high-numerical-aperture imaging fiber bundle with nanodiamonds deposited on its end facet.

In this study, pure Y₂O₃, La_0.1Y_1.9O₃ and La_0.1Nd_0.12Y_1.78O₃ nanosized powders were successfully synthesized by a modified sol–gel method. Pure and rare-earth ions doped yttria powders were characterized by X-ray diffraction, scanning electron microscopy and Brunauer–Emmett–Teller methods. The powders were sintered by the hot isostatic pressing process. The highest in-line transmittance of 56% was obtained at 800 nm and increased in the IR region. The influence of the lanthanum and neodymium ions on the physicochemical properties of yttria were discussed. The La-Nd-doped material exhibited a Verdet constant over 4000 deg/T·m at 400 nm and low thermal dependence. An interesting evolution of the Verdet constant across the absorption band with high resolution was studied. A study of the optical and magneto-optical properties of yttria doped with Nd³⁺ and La³⁺ is discussed in this paper.

A series of silicate–phosphate glass materials from the SiO₂-P₂O₅-K₂O-MgO system (pure and doped with sulfur ions) were synthesized by melting raw material mixtures that contained activated carbon as a reducer. The bulk composition of glass was confirmed with X-ray fluorescence spectroscopy. The homogeneity of the glass was confirmed through elemental mapping at the microstructural level with scanning electron microscopy combined with an analysis of the microregions with energy-dispersive X-ray spectroscopy. The structural and optical properties of the glass were studied by using spectroscopic techniques. The infrared spectroscopy studies that were conducted showed that the addition of sulfur caused changes in the silicate–phosphate networks, as they became more polymerized, which was likely related to the accumulation of potassium near the sulfur ions. By using irradiation with an optical parametric oscillator (OPO) nanosecond laser system operating at the second harmonic wavelength, the glass samples emitted a wide spectrum of luminescence, peaking at about 700 nm when excited by UV light (210–280 nm). The influence of the glass composition and the laser-processing parameters on the emission characteristics is presented and discussed. This work also referred to the density, molar volume, and theoretical optical basicity of pure and sulfur-doped glass.

Lead-free Ba_1−xSr_xTiO₃ (BST) (x = 0, 0.1, 0.2, 0.3, 0.4 and 0.45) ceramics were successfully prepared via the solid-state reaction route. A pure perovskite crystalline structure was identified for all compositions by X-ray diffraction analysis. The basic phase transition temperatures in these ceramics were studied over a wide temperature range. A change in symmetry from a tetragonal to cubic phase was detected, which was further proven by phonon anomalies in composition/temperature-dependent Raman spectra. The incorporation of Sr²⁺ into BaTiO₃ (BT) lead to a shift in the phase transitions to lower temperatures, suppressing the ferroelectric properties and inducing relaxor-like behavior. Therefore, it was reasonable to suppose that the materials progressively lack long-range ordering. The initial second-harmonic generation (SHG) measurements demonstrated that the cubic phase of BST ceramics is not purely centrosymmetric over a wide temperature interval. We discussed the possible origin of the observed effects, and showed that electric field poling seems to reconstruct the structural ordering destroyed by the introduction of Sr²⁺ to BT. In the first approximation, substitution of Sr for larger Ba simply reduced the space for the off-central shift in Ti in the lattice and hence the domain polarization. A-site cation ordering in BST and its influence on the density of electronic states were also explored. The effect of doping with strontium ions in the BST compound on the density of electronic states was investigated using ab initio methods. As the calculations showed, doping BT with Sr²⁺ atoms led to an increase in the bandgap. The proposed calculations will also be used in the subsequent search for materials optimal for applications in photovoltaics.

Anodised metal matrices represent a versatile and multifunctional platform for the development of advanced materials with tunable physicochemical properties. Through electrochemical oxidation processes—commonly referred to as anodisation—metals such as aluminium, titanium, niobium, zinc and tantalum can be transformed into structured oxide layers with defined porosity, thickness and surface morphology. These methods enable the fabrication of ordered nanoporous arrays, nanotubes and nanowires, depending on the process parameters and the type of metal. The review introduces and outlines the various anodisation techniques and parameters. This is crucial, since each individual metal requires specified optimal conditions to obtain a stable anodised oxide layer. This review provides an overview of recent advances in the design and application of anodised metal substrates, with the focus on their role as functional platforms in catalysis, sensing, energy storage and biomedical engineering. Special attention is given to post-anodisation surface modification strategies, such as chemical functionalisation, thin-film deposition and molecular-level integration, which significantly expand the utility of these materials. The review also highlights the challenges, limitations and future perspectives of anodising technologies, aiming to guide the rational design of next-generation devices based on engineered oxide architectures.

In this paper, physicochemical properties of pure Y₂O₃ and samarium (Sm)-doped Y₂O₃ transparent ceramics obtained via arc plasma melting are presented. Yttria powder with a selected molar fraction of Sm was first synthesized by a solid-state reaction method. High transparent yttria ceramics were obtained by arc plasma melting from both the pure and Sm oxide-doped powders. The morphological, chemical and physical properties were investigated by X-ray diffraction and scanning electron microscopy. The optical band gap was calculated from the absorption spectra so as to understand the electronic band structure of the studied materials. Samples indicate a series of luminescence bands in the visible region after excitation by laser light in the range from 210 to 250 nm. Magneto-optical measurements were carried out in the 300–800 nm range at room temperature. It can be seen that a maximum Verdet constant ca. 24.81 deg/T cm was observed for 405 nm and this value decreases with increasing wavelength. The potential usefulness of the polycrystalline material dedicated to optics devices is presented.