34 results match your criteria: "Republic of Moldova [3] Institute of Electronic Engineering and Nanotechnologies[Affiliation]"

Thanks to their simple synthesis, controlled physical properties, and minimal toxicity, iron oxide nanoparticles (FeO NPs) are widely used in many biomedical applications (e.g., bioimaging, drug delivery, biosensors, diagnostics, and theranostics).

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We consider properties of dichroic antenna arrays on a silicon substrate with integrated cold-electron bolometers to detect radiation at frequencies of 210 and 240 GHz. This frequency range is widely used in cosmic microwave background experiments in space, balloon, and ground-based missions such as BICEP Array, LSPE, LiteBIRD, QUBIC, Simons Observatory, and AliCPT. As a direct radiation detector, we use cold-electron bolometers, which have high sensitivity and a wide operating frequency range, as well as immunity to spurious cosmic rays.

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Ultralow voltage (1V) electrical switching of SnS thin films driven by a vertical electric field.

Nanotechnology

February 2023

National Center for Materials Study and Testing, Technical University of Moldova, 168 Stefan cel Mare Av., 2004 Chisinau, Moldova.

In this paper, we show in a series of experiments on 10 nm thick SnS thin film-based back-gate transistors that in the absence of the gate voltage, the drain current versus drain voltage (-) dependence is characterized by a weak drain current and by an ambipolar transport mechanism. When we apply a gate voltage as low as 1V, the current increases by several orders of magnitude and the-dependence changes drastically, with the SnS behaving as a-type semiconductor. This happens because the current flows from the source (S) to the drain (D) electrode through a discontinuous superficial region of the SnS film when no gate voltage is applied.

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The present paper considers a mathematical model describing the time evolution of spin states and magnetic properties of a nanomaterial. We present the results of two variants of nanosystem simulations. In the first variant, cobalt with a structure close to the hexagonal close-packed crystal lattice was considered.

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A series of ZnMgO thin films with ranging from 0 to 0.8 were prepared by spin coating and aerosol spray pyrolysis deposition on Si and quartz substrates. The morphology, composition, nano-crystalline structure, and optical and vibration properties of the prepared films were studied using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), and optical and Raman scattering spectroscopy.

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Uniform nanogranular NiFe layers with Ni contents of 65%, 80%, and 100% have been electroplated in the potentiostatic deposition mode on both planar substrates and arrays of nanowires prepared by the anodization of GaAs substrates. The fabricated planar and coaxial core-shell ferromagnetic structures have been investigated by means of scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). To determine the perspectives for applications, a comparative analysis of magnetic properties, in terms of the saturation and remanence moment, the squareness ratio, and the coercivity, was performed for structures with different Ni contents.

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Ultrathin tin sulfide field-effect transistors with subthreshold slope below 60 mV/decade.

Nanotechnology

July 2022

National Center for Materials Study and Testing, Technical University of Moldova, 168 Stefan cel Mare Av., 2004 Chisinau, Moldova.

In this paper, we present for the first time a field-effect-transistor (FET) having a 10 nm thick tin sulfide (SnS) channel fabricated at the wafer scale with high reproducibility. SnS-based FETs are in on-state for increasing positive back-gate voltages up to 6 V, whereas the off-state is attained for negative back-gate voltages not exceeding -6 V, the on/off ratio being in the range 10-10depending on FET dimensions. The SnS FETs show a subthreshold slope (SS) below 60 mV/decade thanks to the in-plane ferroelectricity of SnS and attaining a minimum value SS = 21 mV/decade.

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The hardware implementation of signal microprocessors based on superconducting technologies seems relevant for a number of niche tasks where performance and energy efficiency are critically important. In this paper, we consider the basic elements for superconducting neural networks on radial basis functions. We examine the static and dynamic activation functions of the proposed neuron.

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Microplastics are one of the major contaminants of aquatic nature where they can interact with organic and inorganic pollutants, including trace metals, and adsorb them. At the same time, after the microplastics have entered the aquatic environments, they are quickly covered with a biofilm - microorganisms which are able to produce extracellular polymeric substances (EPS) that can facilitate sorption of trace metals from surrounding water. The microbial community of biofilm contains bacteria which synthesizes EPS with antimicrobial activity making them more competitive than other microbial inhabitants.

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The preparation of GaAs nanowire templates with the cost-effective electrochemical etching of (001) and (111)B GaAs substrates in a 1 M HNO electrolyte is reported. The electrochemical etching resulted in the obtaining of GaAs nanowires with both perpendicular and parallel orientations with respect to the wafer surface. Core-shell GaAs-Fe nanowire arrays have been prepared by galvanostatic Fe deposition into these templates.

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In this paper we present the microwave properties of tin sulfide (SnS) thin films with the thickness of just 10 nm, grown by RF magnetron sputtering techniques on a 4 inch silicon dioxide/high-resistivity silicon wafer. In this respect, interdigitated capacitors in coplanar waveguide technology were fabricated directly on the SnS film to be used as both phase shifters and detectors, depending on the ferroelectric or semiconductor behaviour of the SnS material. The ferroelectricity of the semiconducting thin layer manifests itself in a strong dependence of the electrical permittivity on the applied DC bias voltage, which induces a phase shift of 30 degrees mmat 1 GHz and of 8 degrees mmat 10 GHz, whereas the transmission losses are less than 2 dB in the frequency range 2-20 GHz.

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Employment of the non-trivial proximity effect in superconductor/ferromagnet (S/F) heterostructures for the creation of novel superconducting devices requires accurate control of magnetic states in complex thin-film multilayers. In this work, we study experimentally in-plane transport properties of microstructured Nb/Co multilayers. We apply various transport characterization techniques, including magnetoresistance, Hall effect, and the first-order-reversal-curves (FORC) analysis.

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This work is a study of the formation processes and the effect of related process parameters of multilayer nanosystems and devices for spintronics. The model system is a superconducting spin valve, which is a multilayer structure consisting of ferromagnetic cobalt nanolayers separated by niobium superconductor nanolayers. The aim was to study the influence of the main technological parameters including temperature, concentration and spatial distribution of deposited atoms over the nanosystem surface on the atomic structure and morphology of the nanosystem.

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Functional nanostructures for electronics, spintronics and sensors.

Beilstein J Nanotechnol

November 2020

D. Ghitu Institute of Electronic Engineering and Nanotechnologies, Chisinau, Moldova and Orel State University, Orel, Russia.

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Article Synopsis
  • The research investigates the proximity effect in superconductor/ferromagnetic superlattices, focusing on how variations in ferromagnetic layer thickness and coercive fields affect superconductivity.
  • Using the Usadel equations, the study identifies conditions under which the magnetic alignment of adjacent ferromagnetic layers leads to significant changes in the superconducting order parameter.
  • Experimental observations show that the resistive transition of a Nb/Co multilayer exhibits multiple steps, indicating that local magnetization affects superconductive behavior, suggesting potential applications in tunable kinetic inductors for artificial neural networks.
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Proximity effect in [Nb(1.5 nm)/Fe()]/Nb(50 nm) superconductor/ferromagnet heterostructures.

Beilstein J Nanotechnol

August 2020

Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, D-70569 Stuttgart, Germany.

We have investigated the structural, magnetic and superconduction properties of [Nb(1.5 nm)/Fe()] superlattices deposited on a thick Nb(50 nm) layer. Our investigation showed that the Nb(50 nm) layer grows epitaxially at 800 °C on the AlO(1-102) substrate.

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A series of Zn Mg O thin films with the composition range = 0.00-0.40 has been prepared by sol-gel spin coating on Si substrates with a post-deposition thermal treatment in the temperature range of 400-650 °C.

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Periodic Co/Nb pseudo spin valve for cryogenic memory.

Beilstein J Nanotechnol

April 2019

Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, D-70569 Stuttgart, Germany.

We present a study of magnetic structures with controllable effective exchange energy for Josephson switches and memory applications. As a basis for a weak link we propose to use a periodic structure composed of ferromagnetic (F) layers spaced by thin superconductors (s). Our calculations based on the Usadel equations show that switching from parallel (P) to antiparallel (AP) alignment of neighboring F layers can lead to a significant enhancement of the critical current through the junction.

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The predictions of Moore's law are considered by experts to be valid until 2020 giving rise to "post-Moore's" technologies afterwards. Energy efficiency is one of the major challenges in high-performance computing that should be answered. Superconductor digital technology is a promising post-Moore's alternative for the development of supercomputers.

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In present work, the nano- and microscale tetrapods from zinc oxide were integrated on the surface of Aerographite material (as backbone) in carbon-metal oxide hybrid hierarchical network via a simple and single step magnetron sputtering process. The fabricated hybrid networks are characterized for morphology, microstructural and optical properties. The cathodoluminescence investigations revealed interesting luminescence features related to carbon impurities and inherent host defects in zinc oxide.

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Article Synopsis
  • A novel electrochemical method is used to create light-driven titanium dioxide (TiO) microengines with precise designs to enhance their performance.
  • The TiO microengines, made from nanoscale arrays of varying diameter nanotubes, show efficient motion in response to UV-light, particularly benefiting from their conical internal structure.
  • The findings suggest these microengines can effectively transport particles and improve environmental cleanup by breaking down organic pollutants more efficiently due to their unique movement capabilities.
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Background: In nanoscale layered S/F1/N/F2/AF heterostructures, the generation of a long-range, odd-in-frequency spin-projection one triplet component of superconductivity, arising at non-collinear alignment of the magnetizations of F1 and F2, exhausts the singlet state. This yields the possibility of a global minimum of the superconducting transition temperature T c, i.e.

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Three-dimensional Aerographite-GaN hybrid networks: single step fabrication of porous and mechanically flexible materials for multifunctional applications.

Sci Rep

March 2015

1] National Center for Materials Study and Testing, Technical University of Moldova, Chisinau, Republic of Moldova [2] Department of Physics and Engineering, State University of Moldova, Chisinau, Republic of Moldova [3] Institute of Electronic Engineering and Nanotechnologies, Academy of Sciences of Moldova, Chisinau, Republic of Moldova.

Three dimensional (3D) elastic hybrid networks built from interconnected nano- and microstructure building units, in the form of semiconducting-carbonaceous materials, are potential candidates for advanced technological applications. However, fabrication of these 3D hybrid networks by simple and versatile methods is a challenging task due to the involvement of complex and multiple synthesis processes. In this paper, we demonstrate the growth of Aerographite-GaN 3D hybrid networks using ultralight and extremely porous carbon based Aerographite material as templates by a single step hydride vapor phase epitaxy process.

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