In this work, stabilized f-ZrO2 ceramic samples with the compositions of (Zr0.82Y0.09Eu0.09)O1.91, (Zr0.82Y0.09Tb0.09)O1.91 and (Zr0.82Y0.09Eu0.045Tb0.045)O1.91 were studied. The elemental composition was studied by electron probe microanalysis, and the luminescent properties were studied by local cathodoluminescence (CL). An analysis of the Eu3+ CL spectra confirmed the stabilization of the cubic phase in ceramics at room temperature. The study of the obtained CL spectra, the 5D4-7F5Tb3+ band luminescence decay kinetics, CL images and excitation spectra showed europium sensitization by terbium in (Zr0.82Y0.09Eu0.045Tb0.045)O1.91. Keywords: f-ZrO2, Eu3+, Tb3+, Ceramics, Sensitization, Cathodoluminescence

The ceramics based on cubic (Zr0.82–xHfxY0.17Eu0.01)O0.91 with different contents of hafnium were studied. In the work, the elemental composition of the samples was obtained, the cathodoluminescence (CL) spectra and decay kinetics of europium luminescence were studied. The researched showed increase in the content of hafnium doesn’t affect the position and number of observed bands in the luminescence spectrum. The electric dipole and magnetic dipole radiative transitions ratio was estimated for all samples. It’s demonstrated that a decrease in the local symmetry of the europium ion associated with an increase in the hafnium content. It’s shown the 5D0–1F1 transition Eu3+ decay time doesn’t depend on the hafnium content, but v-aries significantly in different regions of the sample, which can be attributed to the influence of grain bou-ndaries.

The optimal temperature regime for the synthesis of glass ceramics with YNbO4:Tb3+ crystalline inclusions has been established. Glass ceramics were synthesized on the basis of a sodium borate matrix from oxide precursors. It has been established that synthesis at a temperature of 950°C is optimal, since at this temperature only one crystalline phase YNbO4:Tb3+ is formed in the glass and its content is maximum. The spectra of crystalline inclusions and the glass matrix were obtained by the method of local cathodoluminescence, the phase composition of glass ceramics was studied by X-ray phase analysis.

The effect of sodium adsorption on a gold film deposited on a tungsten substrate was studied. The deposition of Na atoms onto a thin film of gold on tungsten leads to a change in the spectra of the valence band and the core levels of gold and tungsten. An analysis of the spectra showed that the sodium atoms in the surface layer are in a neutral state, and the diffusion of sodium atoms deep into the gold film leads to the formation of the NaxAuy intermetallic compound. Heating a gold film with the formed NaxAuy intermetallic compound at a temperature 640 K leads to partial desorption of sodium and gold atoms from the surface layer of the NaxAuy intermetallic compound.

This work is devoted to the study of the luminescence inhomogeneity nature of bulk (GaxAl1–x)2O3 samples grown by the Czochralski method. In the study of sample cleavages by the local cathodoluminescence method, regions with different luminescence were observed. To determine the cathodoluminescence contrast nature, we studied the uniformity of the aluminum distribution, the surface topography, and compared the luminescence spectra and the kinetics of emission bands for different regions of the sample. Also, to determine the luminescence bands nature, the crystal was annealed in air at 1000°C. This made it possible to observe the change in luminescence for the same region of the sample. Based on the studies performed, it was concluded that inhomogeneous luminescence is associated with the distribution of point defects. Upon annealing in air, the transformation of nonradiative recombination centers into luminescent centers was observed.

The purpose of this work is development of glasses for radioactive materials encapsulation. Borosilicate-based glass systems R7/T7 (B2O3-ЅіO2-Al2O3-Na2O-СaO) doped with Eu3+, with various concentrations of activator were studied. The composition of the obtained glasses was investigated using electron-probe microanalysis technique. Optical properties of glasses were investigated using the following methods – cathodoluminescence, photoluminescence and absorption spectra. The range of the optimal activator concentration was determined.Samples of borosilicate glass (B2O3-ЅіO2-Al2O3-Na2O-СaO) doped with varied content of Eu3+ were synthesized and studied using electron probe microanalysis (EPMA) and optical techniques such as cathodoluminescence (CL), photoluminescence (PL) and light absorption spectroscopy. Glass composition was related to development of nuclear waste form or encapsulation matrix with sufficient resistance to radiation damage. It was observed that electron beam irradiation suppresses intensity of glass cathodoluminescence and this process is correlated with sodium diffusion outside irradiated area at comparable interval of time

The optimal temperature regime for the synthesis of glass ceramics with YNbO 4 :Tb 3+ crystalline inclusions has been established. Glass ceramics were synthesized on the basis of a sodium borate matrix from oxide precursors. It has been established that synthesis at a temperature of 950°C is optimal, since at this temperature only one crystalline phase YNbO 4 :Tb 3+ is formed in the glass and its content is maximum. The spectra of crystalline inclusions and the glass matrix were obtained by the method of local cathodoluminescence, the phase composition of glass ceramics was studied by X-ray phase analysis.

This work is devoted to the study of the luminescence inhomogeneity nature of bulk (GaxAl1-x)2O3 samples grown by the Czochralski method. In the study of sample cleavages by the local cathodoluminescence method, regions with different luminescence were observed. To determine the cathodoluminescence contrast nature, we studied the uniformity of the aluminum distribution, the surface topography, and compared the luminescence spectra and the kinetics of emission bands for different regions of the sample. Also, to determine the luminescence bands nature, the crystal was annealed in air at 1000oC. This made it possible to observe the change in luminescence for the same region of the sample. Based on the studies performed, it was concluded that inhomogeneous luminescence is associated with the distribution of point defects. Upon annealing in air, the transformation of nonradiative recombination centers into luminescent centers was observed. Keywords: gallium oxide, luminescence, point defects.

Layers of ZnSe and ZnCdxSe (x ~ 0.32-0.35) grown on GaAs (001) substrates by molecular beam epitaxy method were investigated. The electron beam impact on changes in crystal structure of specimens under examination and on their luminescent properties was studied. Methods of cathode luminescence, transmission electron microscopy, and electron microprobe analysis were applied. It is found that irradiation of specimens in the transmission electron microscope results in stacking faults annealing accompanied by formation of ZnO precipitates with hexagonal crystal structure. Irradiation of specimens in the cathode luminescence plant results in decreased intensity of cathode luminescence layers of ZnSe and ZnCdxSe in question due to radiation-stimulated degradation processes. Key words: point defects, irradiation by electron beam, cathode luminescence, structural changes.

Lanthanum-doped (La:(HfZr)O2) nanometer films of a solid solution of hafnium oxide and zirconium oxide are of great interest for the development of a universal memory that combines an unlimited number of RAM reprogramming cycles and nonvolatile flash memory. This work is devoted to studying the cathodoluminescent properties of La : HfZrO thin films with different contents of lanthanum. It is shown that the cathodoluminescence spectra are dominated by two emission bands with intensity maxima at 2.7 and 2.2 eV. The blue band with an energy of 2.7 eV is due to an oxygen vacancy in La : HfZrO. The study of the influence of the lanthanum impurity and annealing of the samples in argon suggests that the yellow band with the emission maximum at 2.2 eV is related to the oxygen divacancy. Keywords: luminescence, hafnium oxide, zirconium oxide, oxygen vacancy.

Photoelectron spectroscopy was used to study the electronic structure in situ in an ultrahigh vacuum before and after the adsorption of sodium atoms on the surface of tungsten oxidized at an oxygen pressure of 1 Torr and a temperature of 950 K. The photoemission spectra from the valence band and the W 4f, O 2s, and Na 2p core states were studied under synchrotron excitation in the photon energy range 80-600 eV. It is found that a tungsten oxide film is formed containing various tungsten oxides with an oxidation state of 6+ to 4+. The deposition of a 1.1 monolayer of sodium atoms on the surface of oxidized tungsten leads to the reduction of the W6+ states to W4+ and the reaction with oxygen in the hydroxyl composition, which is reflected in the change in the spectrum of the W 4f and O 2s core states. It is shown that the cathodoluminescence spectrum is associated with the luminescence of tungsten oxide. Keywords: adsorption, sodium, tungsten oxides, photoelectron spectroscopy, cathodoluminescence.

The effect of chemical passivation in solutions of ammonium sulfide (NH4)(2)S on the optical and electronic properties of the surface n-InP (001) is studied. It is shown that treatment in a 4% aqueous solution of (NH4)(2)S leads to a twofold decrease in the surface field and charges localized in this region. Treatment in a 4% alcohol solution (NH4)(2)S leads to a decrease in these parameters by a factor of 3, and, moreover, the barrier photovoltage decreases by a factor of 3.

In this work, a method for estimating the saturation time of traps in dielectric layers based on the KPM is proposed. Using hafnium oxide layers as an example, it is shown that when charging with a series of points with different durations, a different dependence of the residual potential on time is observed. It is assumed that this technique makes it possible to evaluate the performance of devices based on dielectric layers.

In this work, we investigated bulk β-Ga2O3 samples grown by the Czochralski method on Al2O3 and β-Ga2O3 seeds. The elemental composition of the samples and its effect on the luminescent and electrophysical properties of the samples were determined. The Kelvin probe microscopy was used to study the processes of localization and dissipation of charges in the samples. It was shown that in a β-Ga2O3 sample grown on an Al2O3 seed, the characteristic charge dissipation time is 10 times longer.

This work is devoted to the study of self-glowing crystals containing alpha-radionuclides based on YPO4: Eu3+,238Pu, ZrSiO4:Tb3+,238Pu and ceramics based on cubic ZrO2:Eu3+,238Pu obtained in 2006, 2011, and 2017, respectively. The decay of a radionuclide causes radioluminescence of emission centers in the crystal causing its self-glowing. The paper presents the results of theoretical calculations of the energy conversion of alpha particles formed as a result of the radioactive decay of 238Pu, investigates the effect of radioactive decay on the luminescent properties of crystals, and proposes a method for estimating the power density of luminescence excitation during alpha decay. As a result of this work, the main ways of increasing the light yield for self-glowing crystals are proposed.

The electronic structure of thermally oxidized tungsten used as an emitter in thermal ionization of organic molecules is studied. Tungsten foil was thermally oxidized at oxygen pressure 1 Torr and temperature 950 K. The photoemission spectra from the valence band and O 2s and W 4f core levels are studied under synchrotron excitation with the photon energies 100 ÷ 600 eV. It is shown that thermal oxidation of tungsten leads to the formation in the W near-surface region various tungsten oxides with an oxidation state from 6+ to 4+. In this case, mainly tungsten oxides with an oxidation state of 6+ are formed on the surface, the proportion of which gradually decreases with distance from the surface with an increase in tungsten oxides with an oxidation state of 4+.