Ultrastrong photon-to-magnon coupling in multilayered heterostructures involving superconducting coherence via ferromagnetic layers

The critical step for future quantum industry demands realization of efficient information exchange between different-platform hybrid systems that can harvest advantages of distinct platforms. The major restraining factor for the progress in certain hybrids is weak coupling strength between the elemental particles. In particular, this restriction impedes a promising field of hybrid magnonics. In this work, we propose an approach for realization of on-chip hybrid magnonic systems with unprecedentedly strong coupling parameters. The approach is based on multilayered microstructures containing superconducting, insulating, and ferromagnetic layers with modified photon phase velocities and magnon eigenfrequencies. The enhanced coupling strength is provided by the radically reduced photon mode volume. Study of the microscopic mechanism of the photon-to-magnon coupling evidences formation of the long-range superconducting coherence via thick strong ferromagnetic layers in superconductor/ferromagnet/superconductor trilayer in the presence of magnetization precession. This discovery offers new opportunities in microwave superconducting spintronics for quantum technologies

INFLUENCE OF COOLING RATE ON THE STRUCTURE OF FERRITE-MARTENSITE CLASS STEEL

Методом сканирующей электронной микроскопии были исследованы образцы из стали ферритно-мартенситного класса, нагретые в печи до температуры 1000 ℃ и охлажденные при различных скоростях. Охлаждение производилось в воду, на воздухе и в печи. Методами сканирующей электронной микроскопии (СЭМ) и дифракции отраженных электронов (EBSD) определялись характеристики структурных составляющих.Using scanning electron microscopy, ferritic-martensitic steel samples heated in a furnace to a temperature of 1000 ℃ and cooled at different speeds were studied. Cooling was carried out in water, in air and in an oven. The characteristics of the structural components were determined using scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD)

PECULIARITIES OF PHASE TRANSFORMATIONS IN FERRITICMARTENSITIC STAINLESS STEEL

Методами сканирующей электронной микроскопии, включая микрозондовый рентгеноспектральный анализ, установлены структурно-фазовые изменения в нержавеющей стали ферритно-мартенситного класса после термических обработок с различными скоростями охлаждения. В зависимости от скорости охлаждения происходит изменение доли структурных составляющих и перераспределения основных легирующих элементов (Cr, Mo и Mn). Наличие локальных неоднородностей в элементном составе приводит к изменению фазового состава, а именно, к выделению вторых фаз, включающих в себя карбиды на основе Cr и Mo в форме «сеток» по границам ферритных зерен.The methods of scanning electron microscopy, including microprobe X-ray spectral analysis, have established structural and phase changes in stainless steel of ferrite-martensitic class after heat treatment with different cooling rates. Depending on the cooling rate, there is a change in the proportion of structural components and redistribution of the main alloying elements (Cr, Mo and Mn). The presence of local inhomogeneities in the elemental composition leads to a change in the phase composition, namely, to the separation of second phases, including carbides based on Cr and Mo in the form of "meshes" along the boundaries of ferrite grains

Data from: Effect of Hf-doping on electrochemical performance of anatase TiO2 as an anode material for lithium storage

Hafnium-doped titania (Hf/Ti = 0.01; 0.03; 0.05) had been facilely synthesized via a template sol-gel method on carbon fiber. Physicochemical properties of the as-synthesized materials were characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis, scanning transmission electron microscopy, X-ray photoelectron spectroscopy, thermogravimetry analysis, and Brunauer−Emmett−Teller measurements. It was confirmed that Hf4+ substitute in the Ti4+ sites, forming Ti1–xHfxO2 (x = 0.01; 0.03; 0.05) solid solutions with an anatase crystal structure. The Ti1–xHfxO2 materials are hollow microtubes (length of 10–100 μm, outer diameter of 1–5 μm) composed of nanoparticles (average size of 15–20 nm) with surface area of 80–90 m2 g–1 and pore volume of 0.294–0.372 cm3 g–1. The effect of hafnium ions incorporation on electrochemical behavior of anatase TiO2 as Li-ion battery anode was investigated by galvanostatic charge/discharge and electrochemical impedance spectroscopy. It was established that Ti0.95Hf0.05O2 shows significantly higher reversibility (154.2 mAh g–1) after 35-fold cycling at C/10 rate in comparison with undoped titania (55.9 mAh g–1). The better performance offered by Hf4+ substitution of the Ti4+ into anatase TiO2 mainly results from more open crystal structure, which has been achieved via the difference in ionic radius values of Ti4+ (0.604 Å) and Hf4+ (0.71 Å). The obtained results are in a strong accordance with ones for anatase TiO2 doped via Zr4+ (0.72 Å) published earlier. Furthermore, improved electrical conductivity of Hf-doped anatase TiO2 materials due to charge redistribution in the lattice and enhanced interfacial lithium storage due to increased surface area directly depending on Hf/Ti atomic ratio have beneficial effect on electrochemical properties

Zr4+/F– co-doped TiO2(anatase) as high performance anode material for lithium-ion battery

Zr4+ and F– co-doped TiO2 with the formula of Ti0.97Zr0.03O1.98F0.02 was facilely synthesized by a sol-gel template route. The crystal structure, morphology, composition, surface area, and conductivity were characterized by Raman spectroscopy, energy-dispersive X-ray analysis, scanning electron microscopy, Brunauer−Emmett−Teller measurements, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy. The results demonstrate that Zr4+ and F– homogeneously incorporated into TiO2, forming solid solution with an anatase structure. Ti0.97Zr0.03O1.98F0.02 shows outstanding electrochemical properties as Li-ion battery anode in comparison with Ti0.97Zr0.03O2. In particular, upon 35-fold cycling at 1C-rate Zr4+/F– co-doped TiO2 delivers a reversible capacity of 163 mAh g–1, whereas Zr4+-doped TiO2 gives only 34 mA h g–1. Additionally, Zr4+/F– co-doped TiO2 retains a capacity of 138 mA h g–1 during cycling even at 10 C. The enhance performance originates from improved conductivity of Zr4+/F– co-doped TiO2 material through generation of Ti3+ (serving as electron donors) into the crystal lattice and, possibly, due to F-doping blocked the anode surface from attack of HF formed as electrolyte decomposition product. Keywords: Li-ion batteries, TiO2(anatase), Anode, Co-doping, Sol-gel template, Process, Electrochemical performanc

New Polycaprolactone-Containing Self-Healing Coating Design for Enhance Corrosion Resistance of the Magnesium and Its Alloys

The method of hybrid coating formation on the surface of a bioresorbable wrought magnesium alloy and magnesium obtained by additive technology was proposed. Plasma electrolytic oxidation (PEO) with subsequent treatment of the material using an organic biocompatible corrosion inhibitor and a bioresorbable polymer material was used to obtain the protective layers. The optimal method of surface treatment was suggested. Using SEM/EDX analysis, XRD, XPS, and confocal Raman microspectroscopy, the composition of the formed surface layers was determined. The corrosion protection performance of the formed coatings was studied by potentiodynamic polarization and electrochemical impedance spectroscopy techniques in 0.9 wt.% NaCl and HBSS. Hydrogen evolution and mass loss tests were performed to study the corrosion rate of samples with different types of protective coatings. Sealing the pores of PEO coating with a polymeric material contributes to a significant reduction in the amount of the inhibitor diffusing into a corrosive medium. The best barrier properties were established for the hybrid coating formed with a one-stage application of benzotriazole and polycaprolactone. Such layers reduce the rate of alloy degradation due to active protection

Moss-like Hierarchical Architecture Self-Assembled by Ultrathin Na2Ti3O7 Nanotubes: Synthesis, Electrical Conductivity, and Electrochemical Performance in Sodium-Ion Batteries

Nanocrystalline layer-structured monoclinic Na2Ti3O7 is currently under consideration for usage in solid state electrolyte applications or electrochemical devices, including sodium-ion batteries, fuel cells, and sensors. Herein, a facile one-pot hydrothermal synthetic procedure is developed to prepare self-assembled moss-like hierarchical porous structure constructed by ultrathin Na2Ti3O7 nanotubes with an outer diameter of 6–9 nm, a wall thickness of 2–3 nm, and a length of several hundred nanometers. The phase and chemical transformations, optoelectronic, conductive, and electrochemical properties of as-prepared hierarchically-organized Na2Ti3O7 nanotubes have been studied. It is established that the obtained substance possesses an electrical conductivity of 3.34 × 10−4 S/cm at room temperature allowing faster motion of charge carriers. Besides, the unique hierarchical Na2Ti3O7 architecture exhibits promising cycling and rate performance as an anode material for sodium-ion batteries. In particular, after 50 charge/discharge cycles at the current loads of 50, 150, 350, and 800 mA/g, the reversible capacities of about 145, 120, 100, and 80 mA∙h/g, respectively, were achieved. Upon prolonged cycling at 350 mA/g, the capacity of approximately 95 mA∙h/g at the 200th cycle was observed with a Coulombic efficiency of almost 100% showing the retention as high as 95.0% initial storage. At last, it is found that residual water in the un-annealed nanotubular Na2Ti3O7 affects its electrochemical properties