Influence of sputtering parameters on the main characteristics of ultrathin vanadium nitride films
We researched the relation between deposition and ultra-thin VN films parameters.
To conduct the experimental study we varied substrate temperature, Ar and N2 partial pressures
and deposition rate. The study allowed us to obtain the films with close to the bulk values
transition temperatures and implement such samples in order to fabricate superconducting
The relevance of in situ methods for control of nanoscale films parameters is emphasized . The theoretical basis of the method of in situ X-ray reflectivity is considered. The calculations allowed us to estimate the upper-limit of the film absorption for each X-ray wavelength that restricts possibilities of the method
We demonstrate experimentally that single photon detection can be achieved in micron-wide NbN bridges, with widths ranging from 0.53\,μm to 5.15\,μm and for photon-wavelengths from 408\,nm to 1550\,nm. The microbridges are biased with a dc current close to the experimental critical current, which is estimated to be about 50\the theoretically expected depairing current. These results offer an alternative to the standard superconducting single-photon detectors (SSPDs), based on nanometer scale nanowires implemented in a long meandering structure. The results are consistent with improved theoretical modeling based on the theory of non-equilibrium superconductivity including the vortex-assisted mechanism of initial dissipation.
Experimental results on the Au film deposition on the surface of the nanostructured substrate of sapphire by magnetron sputtering are presented. The surface morphology of the films at different modes of application and its change as a result of the heat treatment were studied by atomic force microscopy.
At present particular attention is given to techniques which allow the monitoring of single layer and multilayer thin film materials directly during their formation - in-situ methods. Application of these methods helps to ensure a film with desired characteristics, allowing quickly adjust process conditions. The paper describes the possibilities of the in-situ X-ray reflectivity to determine the parameters of nanoscale films in real time of their formation. Experimental results on the magnetron deposition of nanoscale Si films and other materials on silicon substrates are presented.
The possibilities of obtaining ordered gold nanoarrays on sapphire surfaces with oriented nanorelief are demonstrated. The structures are morphologically described using atomic force microscopy data. A study of the angular dependence of the reflectivity in the visible range of electromagnetic waves has revealed some features which are likely to indicate surface plasmon-polariton excitation at the air-gold interface under exposure to p-polarized radiation. The experimental results are found to be in good agreement with the theoretical calculations.
The dynamics of a two-component Davydov-Scott (DS) soliton with a small mismatch of the initial location or velocity of the high-frequency (HF) component was investigated within the framework of the Zakharov-type system of two coupled equations for the HF and low-frequency (LF) fields. In this system, the HF field is described by the linear Schrödinger equation with the potential generated by the LF component varying in time and space. The LF component in this system is described by the Korteweg-de Vries equation with a term of quadratic influence of the HF field on the LF field. The frequency of the DS soliton`s component oscillation was found analytically using the balance equation. The perturbed DS soliton was shown to be stable. The analytical results were confirmed by numerical simulations.
Radiation conditions are described for various space regions, radiation-induced effects in spacecraft materials and equipment components are considered and information on theoretical, computational, and experimental methods for studying radiation effects are presented. The peculiarities of radiation effects on nanostructures and some problems related to modeling and radiation testing of such structures are considered.
This volume presents new results in the study and optimization of information transmission models in telecommunication networks using different approaches, mainly based on theiries of queueing systems and queueing networks .
The paper provides a number of proposed draft operational guidelines for technology measurement and includes a number of tentative technology definitions to be used for statistical purposes, principles for identification and classification of potentially growing technology areas, suggestions on the survey strategies and indicators. These are the key components of an internationally harmonized framework for collecting and interpreting technology data that would need to be further developed through a broader consultation process. A summary of definitions of technology already available in OECD manuals and the stocktaking results are provided in the Annex section.