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.

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.

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.

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.

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.

The magnetotransport properties of Co x (Al 2 O n ) 100 − x nanocomposites were studied in a wide concentration range (34 ≤ x ≤ 74 at %). Negative tunnel magnetoresistance reaching 6.5% in a field of 10 kOe was established. In addition to the negative magnetoresistance, the Co x (Al 2 O n ) 100 − x composites were found to exhibit positive magnetoresistance reaching 1.5% in fields of 10 kOe over the concentration range corresponding to the percolation threshold (54 ≤ x ≤ 67 at %). The positive magnetoresistance is assumed to be due to the simultaneous existence in the composite structure of clusters and individual nanoparticles characterized by different values of the magnetic anisotropy and due to the dipole-dipole interaction between the clusters and nearest neighbor particles.

The electrical resistance of granular structures with ferromagnetic and nonferromagnetic metal nanoparticles embedded in concentrations below the percolation threshold was studied in strong electric fields. More specifically, amorphous silicon dioxide containing nanoparticles of a Co41Fe39B20 alloy [(a-SiO2)100− x(Co41Fe39B20)x structure] and amorphous hydrogenated carbon with embedded copper nanoparticles, a-C: H(Cu), were investigated. The (a-SiO2)100−x(Co41Fe39B20)x structures revealed changes in the electrical resistance and magnetoresistance after being subjected to a strong electric field. The changes could have reversible or irreversible character and depended on the electrical prehistory of the sample. A strong electric field caused not only a decrease in the electrical resistance but also a decrease in the magnetoresistance, although the magnetization of the sample remained unchanged. The temperature dependences of the current in a-C: H(Cu) films exhibited conductivity peaks under a decrease in temperature in strong electric fields and transitions from the insulating to conducting state; after the field was removed, there occurred reverse transitions and conductivity relaxation, as well as pronounced changes in the dielectric permittivity and an increase in dielectric losses with increasing temperature. A model of cluster electronic states (CESs) is proposed to account for the experimental findings. These states are created by electrons of the metal grains and matrix defects near the Fermi surface. The observed features find explanation in a change in the CES structure. A strong electric field does not bring about d-electron delocalization, and the fraction of d electron wave functions in a CES is small.