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Fiber-optic sensors find numerous applications in science and industry, but their full potential is limited because of the risk of damaging the measurement head, in particular, due to the vulnerability of unprotected tips of the fiber to mechanical damage and aggressive chemical agents. In this paper, we report the first use of a new nanocrystalline diamond structure in a fiber-optic measurement head as a protective coating of the fiber tip. The nanocrystalline sheet structures, produced with the use of Microwave Plasma Assisted Chemical Vapor Deposition System (MW PA CVD), were characterized by Scanning Electron Microscopy (SEM) and successfully transferred from the deposition substrate onto the surface of the tip of a single-mode fiber sensor head. A Fabry-Perot sensing interferometer for distance measurement comprising that fiber was built. The measurement results were compared with numerical modeling. High values of achieved correlation coefficients (R2 > 0.99) between a linear model and distance measurements data indicate that the diamond sheet does not affect the correct operation of the sensor while extending its potential scope of applications.

The intercalation of layered compounds opens up a vast space of new host-guest hybrids, providing new routes for tuning the properties of materials. Here, it is shown that uniform and continuous layers of copper can be intercalated within the van der Waals gap of bulk MoS

Studies of nanoscale superconducting structures have revealed various physical phenomena and led to the development of a wide range of applications. Most of these studies concentrated on one- and two-dimensional structures due to the lack of approaches for creation of fully engineered three-dimensional (3D) nanostructures. Here, we present a ‘bottom-up’ method to create 3D superconducting nanostructures with prescribed multiscale organization using DNA-based self-assembly methods. We assemble 3D DNA superlattices from octahedral DNA frames with incorporated nanoparticles, through connecting frames at their vertices, which result in cubic superlattices with a 48 nm unit cell. The superconductive superlattice is formed by converting a DNA superlattice first into highly-structured 3D silica scaffold, to turn it from a soft and liquid-environment dependent macromolecular construction into a solid structure, following by its coating with superconducting niobium (Nb). Through low-temperature electrical characterization we demonstrate that this process creates 3D arrays of Josephson junctions. This approach may be utilized in development of a variety of applications such as 3D Superconducting Quantum interference Devices (SQUIDs) for measurement of the magnetic field vector, highly sensitive Superconducting Quantum Interference Filters (SQIFs), and parametric amplifiers for quantum information systems., Fabrication of superconducting 3D nanoarchitectures, using standard nanofabrication methods, is challenging. Here, the authors demonstrate the fabrication of a nanostructured 3D superconducting array of Josephson junctions, exploiting self-assembled DNA origami lattices as a template.

The authors want to acknowledge the financial support of the Polish National Science Centre under Grant No. 2017/25/N/ST7/01610, the Polish National Agency for Academic Exchange NAWA under Bilateral exchange of scientists between France and Poland PHC Polonium PPN/BFR/2019/1/00005/U/00001, Polish National Agency for Academic Exchange under Iwanowska Programme PPN/IWA/2018/1/00026/U/00001, Polish National Agency for Academic Exchange under Iwanowska Programme PPN/IWA/2018/1/00058/U/00001, and DS Programs of Faculty of Electronics, Telecommunications and Informatics of Gdańsk University of Technology. KD thanks the UK Engineering and Physical Sciences Research Council for funding (Grant EP/P030017/1). Fiber optic sensors are widely used in environmental, biological and chemical sensing. Due to the demanding environmental conditions in which they can be used, there is a risk of damaging the sensor measurement head placed in the measuring field. Sensors using nanolayers deposited upon the fiber structure are particularly vulnerable to damage. A thin film placed on the surface of the fiber end-face can be prone to mechanical damage or deteriorate due to unwanted chemical reactions with the surrounding agent. In this paper, we investigated a sensor structure formed with a Zinc Oxide (ZnO) coating, deposited by Atomic Layer Deposition (ALD) on the tip of a single-mode fiber. A nanocrystalline diamond sheet (NDS) attached over the ZnO is described. The diamond structure was synthesized in a Microwave Plasma Assisted Chemical Vapor Deposition System. The deposition processes of the nanomaterials, the procedure of attaching NDS to the fiber end-face covered with ZnO, and the results of optical measurements are presented. Publisher PDF

Similarly to other transition metal sulfides, nickel sulfide nanocrystals can be potentially used for functional device applications. However, controlling morphology and stoichiometry to target specific applications is a synthesis challenge. In this work we developed a rapid, one-step, chemical vapor deposition synthesis of nickel sulfide dendritic nanostructures with fractal geometry. Microtome-EDS compositional analysis of the mature crystal indicates a trend of decreasing sulfur and increasing nickel concentration towards the tip of the mature crystals. Following thorough investigation of these nanocrystals at different stages of their nucleation and growth by means of XRD, HR-SEM, HR-TEM, and Raman spectroscopy, we suggest possible kinetic mechanisms for the crystal formation and development. This work contributes to the understanding of growth mechanisms of dendritic structures with complex morphology.

Due to the global problem with plastic contaminating the environment, with bisphenol A (BPA) being one of the highest demand, effective monitoring and purification of the pollutants are required. The electrochemical methods constitute a good solution but, due to polymerization of electrochemical oxidation bisphenol A products and their adsorption to the surfaces, measurement head elements are clogged by the formed film. In this research, we propose a nanocrystalline diamond sheet protection for securing elements in direct contact with bisphenol A during electrochemical processes. The solution was presented on the example of a zinc oxide (ZnO) coating deposited on a fiber-optic end-face by Atomic Layer Deposition. Series of optical and electrochemical measurements were performed in a dedicated hybrid setup. The results show that ZnO can be modified during the electrochemistry leading to the drastic change of its properties. Such degradation did not show in case of nanocrystalline diamond sheet-protected sample proving the solution’s effectiveness, giving a possibility of re-using the measurement element and prolonging its lifespan.

Focused ion beam (FIB) is an extremely valuable tool in nanopatterning and nanofabrication for potentially high-resolution patterning, especially when refers to He ion beam microscopy. The work presented here demonstrates an 'out-of-the-box' method of writing using FIB, which enables creating very large matrices, up to the beam-shift limitation, in short times and with high accuracy unachievable by any other writing technique. The new method allows combining different shapes in nanometric dimensions and high resolutions for wide ranges.

In this paper, we studied the influence of LiAlO2 coatings of 0.5, 1 and 2 nm thickness prepared by Atomic Layer Deposition onto LiNi0.8Co0.15Al0.05O2 electrodes, on their electrochemical behavior at 30 and 60 degrees C. It was demonstrated that upon cycling, 2 nm LiAlO2 coated electrodes displayed similar to 3 times lower capacity fading and lower voltage hysteresis comparing to bare electrodes. We established a correlation among the thickness of the LiAlO2 coating and parameters of the self-discharge processes at 30 and 60 degrees C. Significant results on the elevated temperature cycling and aging of bare and LiAlO2 coated electrodes at 4.3 V were obtained and analyzed for the first time. By analyzing of X-ray diffraction patterns of bare and 2 nm coated LiNi0.8Co0.15Al0.05O2 electrodes after cycling, we concluded that cycled materials preserved their original structure described by R-3m space group and no additional phases were detected. (c) The Author(s) 2017. Published by ECS. All rights reserved.

The intercalation of layered compounds opens up a vast space of new host-guest hybrids, providing new routes for tuning the properties of materials. Here, it is shown that uniform and continuous layers of copper can be intercalated within the van der Waals gap of bulk MoS2 resulting in a unique Cu-MoS2 hybrid. The new Cu-MoS2 hybrid, which remains semiconducting, possesses a unique plasmon resonance at an energy of ≈1eV, giving rise to enhanced optoelectronic activity. Compared with high-performance MoS2 photodetectors, copper-enhanced devices are superior in their spectral response, which extends into the infrared, and also in their total responsivity, which exceeds 104 A W-1 . The Cu-MoS2 hybrids hold promise for supplanting current night-vision technology with compact, advanced multicolor night vision.

The repeatability of the Raman scattering (RS) spectra was analyzed in monolayer and bilayer CVD-grown graphene films. Position and width of the two main RS lines (G-line and 2D-line) together with their intensity ratio I2D/IG were measured in samples where graphene film was supported by a SiO2/Si substrate and where the film was suspended over pits in the substrate. The results are presented as histograms averaged by a Gaussian with the width W, considered as a measure of non-repeatability. Relatively large fluctuations in the I2D/IG value and linewidth were observed upon repeated measurements at the same point both in supported and suspended samples. The RS measurements in crystalline graphite and mechanically exfoliated graphene deposited on hexagonal boron nitride showed higher repeatability which means that increased W in CVD-grown films reflects the sensitivity of RS processes in these films to changes in charge and deformation. In bilayer CVD samples, the values of W are higher due to additional fluctuations in the twist angle between two misoriented layers. The average position of the RS lines is shifted in opposite directions and makes it possible to distinguish between bilayer and monolayer films, despite the similarity in the RS spectra.

Utilizing self-assembled DNA structures in the development of nanoelectronic circuits requires transforming the DNA strands into highly conducting wires. Toward this end, we investigate the use of DNA self-assembled nanowires as templates for the deposition of a superconducting material. Nanowires formed by the deposition of superconducting NbN exhibit thermally activated and quantum phase slips as well as exceptionally large negative magnetoresistance. The latter effect can be utilized to suppress a significant part of the low temperature resistance caused by the quantum phase slips.

A critical limitation imposed on all imaging systems is to achieve an optimal balance between optical resolution and bandwidth. The optical system determines and affects the relations between temporal information, spatial bandwidth, and resolution, so the resulting signal may differ for each wavelength. This is of significant importance for hyperspectral imaging in particular, because it extracts both spatial and temporal wavelength information. We present a dispersive device that can be used for hyperspectral imaging hypercube image measurements. We utilize the Vernier effect by integrating two silicon slabs that act together as a modified Fabry–Perot filter. The transition between wavelength bands is achieved by heating, utilizing the thermo-optic effect. Importantly, we show that red-shifting with concatenated slabs requires less heating than with a single slab. With the presented technique, a wide effective free spectral range of up to 90 nm around a central wavelength of 1550 nm was achieved along with 20-nm full-width-at-half-maximum resolution. With the same configuration, observing a narrower 0.7-nm free spectral range bandwidth, a fine spectrum resolution of 0.07 nm was obtained. Such variety covers most of the spatial and temporal standard limitations of current hyperspectral imaging requirements.