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L. V. Kutuzov

Bio: L. V. Kutuzov is an academic researcher from Kurchatov Institute. The author has contributed to research in topics: Irradiation & Thin film. The author has an hindex of 3, co-authored 18 publications receiving 35 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, the results of studying the microstructure and superconducting properties of ultrathin films on the basis of NbN in the initial state and after modification by being subjecting to composite ion beam irradiation with the energy ∼(1-3) keV are presented.
Abstract: In this work, the results of studying the microstructure and superconducting properties of ultrathin films on the basis of NbN in the initial state and after modification by being subjecting to composite ion beam irradiation with the energy ∼(1–3) keV are presented. HRTEM analysis showed that the initial films on the sapphire substrate in orientation “c-cut” are characterized by a grain size essentially exceeding the film thickness, while on the other substrates the size of grains corresponds to the thickness of film. Using XPS analysis, it was shown that in the initial films the atomic ratio of Nb and N is 0.51/0.49, respectively, the percentage of oxygen being lower than 5%. For ultrathin films 5 nm in thickness, the critical temperature of transit to superconducting state (T c) is found to be ∼13.6 K and the density of critical current is jc ∼ 8MA/cm2. In the work it is experimentally determined that the irradiation of NbN films by composite ion beams leads to the controlled modification of its superconducting properties due to the process of selective substitution of nitrogen atoms on the oxygen atoms.

11 citations

Journal ArticleDOI
TL;DR: In this article, it is shown experimentally that the use of ion irradiation allows one to convert superconducting thin-film niobium nitride into dielectric Niobium oxide in a controllable manner.
Abstract: It is shown experimentally that the use of ion irradiation allows one to convert superconducting thin-film niobium nitride into dielectric niobium oxide in a controllable manner. The conversion of NbN into Nb2O5 throughout the entire thickness of the film is demonstrated via transmission electron microscopy and layer-by-layer XPS analysis. This conversion is followed by a corresponding increase in the film thickness with no signs of sputtering and thus provides the possibility of forming dielectric regions of the required sizes and shapes in the process of fabrication of various functional cryoelectronic elements.

7 citations

Journal ArticleDOI
TL;DR: In this paper, the electric properties of the metals reduced from oxides using the selective removal of atoms (SRA) under proton irradiation were investigated and the possibility of creating two isolated nanowires at a distance of 70 nm was shown.
Abstract: The electric properties of films of the metals reduced from oxides using the selective removal of atoms (SRA) under proton irradiation were investigated. The electric characteristics of SRA films were found to correspond to characteristics of the deposited films of pure metals. The possibility of creating nanowires in a matrix of initial oxide under irradiation through a PMMA mask was shown. Individual nanowires and pairs of nanowires from bismuth were created. The electric characteristics of both nanowires and leak currents between closely located nanowires were measured. The possibility of creating two isolated nanowires at a distance of 70 nm was shown.

4 citations

Journal ArticleDOI
TL;DR: In this paper, the authors studied the silicon microstructure evolution during its oxidation under composite beam ion irradiation at room temperature and found that when the composite ion beam was formed by hydrogen and dry oxygen mixture at low doses (∼10 18 cm −2 ), a porous silicon layer was formed.
Abstract: In this work, we studied the silicon microstructure evolution during its oxidation under composite beam ion irradiation at room temperature. It was found that when the composite ion beam was formed by hydrogen and dry oxygen mixture at low doses (∼10 18 cm −2 ), a porous silicon layer was formed. During irradiation, the pore size gradually reduced and at a dose of ∼10 20 cm −2 pores disappear completely, and an uniform layer of silicon oxide was formed. If residual gases and hydrogen are used to generate a composite ion beam, the formation of porous silicon is not found. The final thickness of irradiation-induced silicon oxide corresponded to the projected range of protons at a given energy in both cases.

3 citations

Journal ArticleDOI
TL;DR: In this paper, a new technique for manufacturing silicon nanowires on the surface of a conventional silicon wafer using ion-beam irradiation through a lithographic mask has been proposed.
Abstract: A new technique for manufacturing silicon nanowires on the surface of a conventional silicon wafer using ion-beam irradiation through a lithographic mask has been proposed. The conditions needed for synthesizing silicon oxide using the irradiation of the silicon substrate by protons with an energy of about 1 keV have been studied. The possibility of synthesizing silicon oxide in the region of the geometric shadow under the monocrystalline silicon nanowire has been demonstrated.

3 citations


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Journal ArticleDOI
TL;DR: In this article, the authors present a fabrication method of superconducting quantum interference devices (SQUIDs) based on direct write lithography with an Atomic Force Microscope (AFM).
Abstract: We present a fabrication method of superconducting quantum interference devices (SQUIDs) based on direct write lithography with an Atomic Force Microscope (AFM). This technique involves maskless local anodization of Nb or NbN ultrathin films using the voltage biased tip of the AFM. The SQUIDs are of weak-link type, for which two geometries have been tested: Dayem and variable thickness nanobridges. The magnetic field dependence of the maximum supercurrent Ic(flux) in resulting SQUIDs is thoroughly measured for different weak link geometries and for both tested materials. It is found that the modulation shape and depth of Ic(flux) curves are greatly dependent on the weak link size. We analyze the results taking into account the kinetic inductance of nanobridges and using the Likharev-Yakobson model. Finally we show that the present resolution reached by this technique (20nm) enables us to fabricate Nb weak-links which behavior approaches those of ideal Josephson junctions.

36 citations

Journal ArticleDOI
TL;DR: In this paper, the effects of ion irradiation on the chemical composition of thin-film materials have been investigated and two methods, selective atom binding and selective atom substitution, have been proposed for creating composite structures with a locally changed chemical composition and properties.
Abstract: This study is a continuation of works [1–12] dealing with the field developed by the authors, namely, to widen the possibilities of radiation methods for a controlled change in the atomic composition and properties of thin-film materials. The effects under study serve as the basis for the following two methods: selective atom binding and selective atom substitution. Such changes in the atomic composition are induced by irradiation by mixed beams consisting of protons and other ions, the energy of which is sufficient for target atom displacements. The obtained experimental data demonstrate that the changes in the chemical composition of thin-film materials during irradiation by an ion beam of a complex composition take place according to mechanisms that differ radically from the well-known mechanisms controlling the corresponding chemical reactions in these materials. These radical changes are shown to be mainly caused by the accelerated ioninduced atomic displacements in an irradiated material during irradiation; that is, they have a purely radiation nature. The possibilities of the new methods for creating composite structures consisting of regions with a locally changed chemical composition and properties are demonstrated for a wide class of materials.

13 citations

Journal ArticleDOI
TL;DR: In this article, the results of studying the microstructure and superconducting properties of ultrathin films on the basis of NbN in the initial state and after modification by being subjecting to composite ion beam irradiation with the energy ∼(1-3) keV are presented.
Abstract: In this work, the results of studying the microstructure and superconducting properties of ultrathin films on the basis of NbN in the initial state and after modification by being subjecting to composite ion beam irradiation with the energy ∼(1–3) keV are presented. HRTEM analysis showed that the initial films on the sapphire substrate in orientation “c-cut” are characterized by a grain size essentially exceeding the film thickness, while on the other substrates the size of grains corresponds to the thickness of film. Using XPS analysis, it was shown that in the initial films the atomic ratio of Nb and N is 0.51/0.49, respectively, the percentage of oxygen being lower than 5%. For ultrathin films 5 nm in thickness, the critical temperature of transit to superconducting state (T c) is found to be ∼13.6 K and the density of critical current is jc ∼ 8MA/cm2. In the work it is experimentally determined that the irradiation of NbN films by composite ion beams leads to the controlled modification of its superconducting properties due to the process of selective substitution of nitrogen atoms on the oxygen atoms.

11 citations

Journal ArticleDOI
TL;DR: In this article, it is shown experimentally that the use of ion irradiation allows one to convert superconducting thin-film niobium nitride into dielectric Niobium oxide in a controllable manner.
Abstract: It is shown experimentally that the use of ion irradiation allows one to convert superconducting thin-film niobium nitride into dielectric niobium oxide in a controllable manner. The conversion of NbN into Nb2O5 throughout the entire thickness of the film is demonstrated via transmission electron microscopy and layer-by-layer XPS analysis. This conversion is followed by a corresponding increase in the film thickness with no signs of sputtering and thus provides the possibility of forming dielectric regions of the required sizes and shapes in the process of fabrication of various functional cryoelectronic elements.

7 citations