The topological features of the formation of (Co40Fe40B20)15(LiNbO3)85 composite films deposited by ion-beam method on a metal electrode Cr/Cu/Cr has been investigated. The presence of a dielectric layer between the upper Cr layer and the CoFe–LiNbO3 film with a thickness of dox ≈ 15 nm has been established. The difference in the size of granules near the amorphous layer and in the volume of the film has been shown. A model of the formation of (Co40Fe40B20)x (LiNbO3)100 – x nanocomposite film at the initial stage of growth has been proposed. It has been shown that the formation of α-LiNbO3 layer on the chrome metal film surface is possible with the realization of island and layer-by-layer growth mechanisms for various phases of the composite.

The paper reveals the influence of Li, B and the composition of metal contacts on the processes of resistive switching in memristive structures M/NC/D/M. After field exposure in structures Cu/(Co50Fe50)x(LiNbO3)100–x/s-LiNbO3/Cu/sitall, Cu/(Co50Fe50)x(LiNbO3)100–x/d-LiNbO3/Cu/sitall and Cu/(Co40Fe40B20)x(SiO2)100–x/d LiNbO3/Cu/sitall at x < 13 was detected a residual voltage (up to 16 mV) due to the electromigration of Li ions, that leading to a “reversible” type of VAC hysteresis and instability of the time dependencies of induced resistive states. In the structures of Cu/(Co40Fe40B20)x(LiNbO3)100–x/s-LiNbO3/Cu/sitall, Cr/Cu/Cr/(Co40Fe40B20)x(LiNbO3)100–x/s-LiNbO3/Cr/Cu/Cr/sitall containing B, the residual voltage is reduced by formation of chemical compounds B with percolated Li atoms. When limiting the electromigration of Li ions, the main mechanism of resistive switching is the processes of electromigration of oxygen vacancies in the dielectric oxide layer. Suppression of residual voltage in the Cr/Cu/Cr/(Co50Fe50)x(LiNbO3)100–x/s-LiNbO3/Cr/Cu/Cr/sitall structure due to the introduction of a Cr buffer layer that does not dissolve Li leads to the absence of bipolar resistive switching in these structures.

Особенности клеточного иммунитета медицинских работников в первую волну пандемии SARS

The paper reveals the influence of Li, B and the composition of metal contacts on the processes of resistive switching in memristive structures M/NC/D/M. After field exposure in structures Cu/(Co50Fe50)Х(LiNbO3)100-Х/s-LiNbO3/Cu/sitall, Cu/(Co50Fe50)Х(LiNbO3)100-Х/d-LiNbO3/Cu/sitall and Cu/(Co40Fe40B20)Х(SiO2)100-Х/d-LiNbO3/Cu/sitall at x < 13 at.% was detected a residual voltage (up to 16 mV) due to the electromigration of Li ions, that leading to a "reversible" type of VAC hysteresis and instability of the time dependencies of induced resistive states. In the structures of Cu/(Co40Fe40B20)Х(LiNbO3)100-Х/s-LiNbO3/Cu/sitall, Cr/Cu/Cr/(Co40Fe40B20)Х(LiNbO3)100-Х/s-LiNbO3/Cr/Cu/Cr/sitall containing B, the residual voltage is reduced by formation of chemical compounds B with percolated Li atoms. When limiting the electromigration of Li ions, the main mechanism of resistive switching is the processes of electromigration of oxygen vacancies in the dielectric oxide layer. Suppression of residual voltage in the Cr/Cu/Cr/(Co50Fe50)Х(LiNbO3)100-Х/s-LiNbO3/Cr/Cu/Cr/sitall structure due to the introduction of a Cr buffer layer that does not dissolve Li leads to the absence of bipolar resistive switching in these structures.

The effect of oxygen and water vapor in a sputtering chamber during the deposition of thin-film (Co40Fe40B20)x(LiNbO3)100 – x nanocomposites on the electrical properties of the heterogenous system is investigated. It is found that the resistivity of (Co40Fe40B20)x(LiNbO3)100 – x nanocomposites increases significantly with the partial pressure of reactive gases (oxygen and water vapor). A noticeable shift of the percolation threshold towards higher values of the metal phase volume concentration, which is observed in the plane of the film and in the perpendicular direction during the synthesis of composites with the addition of reactive gases, is attributed to the increase in the volume concentration of the dielectric phase. It is found that the percolation threshold for the measurements in the geometry perpendicular to the plane of the film is characterized by a much lower concentration of the Co40Fe40B20 alloy atoms than that for the measurements in the plane of the film, which is associated with an elongated shape of granules in the film growth direction and the effects of Coulomb blockade suppression by a high transverse electric field.

The topological features of the formation of (Co40Fe40B20)15(LiNbO3)85 composite films deposited by ion-beam method on a metal electrode Cr/Cu/Cr has been investigated. The presence of a dielectric layer between the upper Cr layer and the CoFe-LiNbO3 film with a thickness of dox~ 15 nm has been established. The difference in the size of granules near the amorphous layer and in the volume of the film has been shown. A model of the formation of (Co40Fe40B20)x(LiNbO3)100-x nanocomposite film at the initial stage of growth has been proposed. It has been shown that the formation of α-LiNbO3 layer on the chrome metal film surface is possible with the realization of island and layer-by-layer growth mechanisms for various phases of the composite. Keywords: nanocomposite, growth mechanisms, self-organization, structure.

Influence of oxygen and water vapor in vacuum chamber during the deposition process of (Co40Fe40B20)x(LiNbO3)100-x thin film nanocomposites on electrical properties has been investigated. A significant growth in the electrical resistivity of (Co40Fe40B20)x(LiNbO3)100-x nanocomposites has been established with an increase in reactive gases partial pressure (oxygen and water vapor). It has been found, that the recrystallization temperature of composites deposited in argon atmosphere also increases with metallic phase concentration. While the recrystallization temperature of (Co40Fe40B20)x(LiNbO3)100-x nanocomposites sinthesized in mixed atmosphere of Ar with the reactive gases (oxygen or water vapor) decreases due to increase of the heterogeneous structure oxidation. Keywords: Metal-insulator nanocomposites, electrical resistivity, thermal stability, phase composition, oxygen, water vapor.

Influence of oxygen and water vapor in the chamber during the deposition of thin-film nanocomposites (Co40Fe40B20)x(LiNbO3)100-x on the electrical properties of the heterogeneous system has been studied. A significant increase in the resistivity of (Co40Fe40B20)x(LiNbO3)100-x nanocomposites with an increase in the partial pressure of reactive gases (oxygen and water vapor) has been established. A significant shift of the percolation threshold towards higher metal phase concentration in the film plane and perpendicular to the film was found during the synthesis of composites with the addition of reactive gases, which is associated with an increase in the volume concentration of the dielectric phase. It is revealed that the percolation threshold when measured in the geometry perpendicular to the plane of the film corresponds to a significantly lower concentration of atoms of the Co40Fe40B20 alloy than in the case of measurements in the plane of the film, which is associated with the elongated shape of the metallic granules in the direction of film growth and the effects of Coulomb blockade suppression by a high transverse electric field.

A heterogeneous multilayer system (Co40Fe40B20)34(SiO2)66/ZnO was obtained by ion-beam sputtering. X-ray diffraction analysis showed that the obtained films have an amorphous multilayer structure. Transmission electron microscopy analysis (TEM) confirmed the formation of separated (Co40Fe40B20)34(SiO2)66 and ZnO layers. The (Co40Fe40B20)34(SiO2)66 composite layers are monogranular with a metal particle size of 1 nm. The thin films remain stable after heat treatment at temperatures up to 350 °C. Measurement of the electrical resistance confirms the formation of a multilayer structure and crystallization of films after heating above 350 °C.

The analysis of long-term results of treatment of 88 primary patients with colon adenocarcinoma at various stages of tumor process is presented, taking into account the TNM system criteria, and serum IGF-1, IGF-2, IGFBP-1, IGFBP-2, IGFBP-3, VEGF, and MMP-7 levels. The overall survival rate assessed by Kaplan-Meier method and Cox multivariate regression model was used as the criterion of prognosis. It was established that IGF-1, IGFBP-2 and VEGF serum levels along with the stage of colorectal cancer might be considered as statistically significant independent predictors of overall survival in patients.

Изучен эффект резистивного переключения (РП) в структурах на базе композита (CoFeB)x(LiNbO3)100-I. Обнаружено, что структуры демонстрируют стабильные РП с характеристиками, необходимыми для построения нейроморфных систем. Предложена качественная модель переключения, основанная на многофиламентном характере РП.

We have studied the structure and electrical properties of thin films based on the In2O3 semiconductor and carbon, grown by atomic layer deposition using ion-beam sputtering. The structure of the resultant materials, formed during layer-by-layer growth of island layers, is made up of nanocrystalline In2O3 granules distributed at random over amorphous carbon. The electrical transport properties of the In2O3/C thin films depend on their thickness. In the temperature range 80–300 K, the dominant electrical transport mechanism in the In2O3/C thin films of thickness h < 70 nm sequentially changes from variable range hopping between localized states in a narrow energy band near the Fermi level (between 80 and 120 K) to nearest neighbor hopping (between 120 and 250 K) and then to variable range hopping between localized states in the conduction band tail (between 250 and 300 K). The films of thickness h > 70 nm undergo a change from conduction associated with strong carrier localization to that due to the presence of percolation clusters formed by In2O3 nanocrystals, which shows up as a linear temperature dependence of conductivity, with a negative temperature coefficient.

An investigation is performed of the thermal stability and phase transformations of thin-film heterogeneous [(Co 40 Fe 40 B 20 ) 34 (SiO 2 ) 66 /ZnO/In 2 O 3 ] 85 multilayers obtained via ion beam sputtering. The system contains 85 layers, each consisting of a (Co 40 Fe 40 B 20 ) 34 (SiO 2 ) 66 composite layer and ZnO and In 2 O 3 semiconductor spacers. The sample structure in the initial state and after heat treatment is studied by means of X-ray diffraction. It is shown that the samples are stable at temperatures of up to 500°С. Zn 2 SiO 4 , InBO 3 , CoFe, and In 2 O 3 phases form during annealing.

Multilayer films (In 2 O 3 /SnO 2 ) 69 are obtained via ion-beam sputtering. The effect vacuum heat treatment in the range of room temperature to 600°C has on the structure and electrical properties is studied. It is found that the structures obtained with different thicknesses of the In 2 O 3 /SnO 2 bilayer are stable up to a heat treatment temperature of 400°С. Raising the temperature to 600°C alters the sign of the coefficient of temperature resistance from negative to positive.

Multilayered [(Co 40 Fe 40 B 20 ) 34 (SiO 2 ) 66 /ZnO] 112 , [(Co 40 Fe 40 B 20 ) 34 (SiO 2 ) 66 /SnO 2 ] 32 , and [(Co 40 Fe 40 B 20 ) 34 (SiO 2 ) 66 /In 2 O 3 ] 92 films with layers 1 nm thick are obtained via the ion-beam sputtering of two targets onto a rotating substrate. Their phase transformations are studied during the thermal treatment of films. Compounds with boron form in films with ZnO and In 2 O 3 buffer layers (Co 2 FeO 2 (BO 3 ) and InBO 3 , respectively). The composition of these compounds is found to depend on the semiconductor that is used and the ratio of layer thickness.