We experimentally demonstrate the nanoscale resistivity-scaling behavior of topological conductors using cobalt monosilicide (CoSi) nanowires (NWs) fabricated on 200 mm wafers with CMOS-compatible processes. Both templated near-epitaxial and polycrystalline CoSi NWs are evaluated, with cross-sectional areas down to $35 \text{nm}^{2}(\sim 6 \text{nm}$ diameter). Unlike Cu, which shows a steep resistivity increase below $\sim 20 \text{nm}$ linewidth, templated near-epitaxial CoSi NWs show an exceptional $\sim 80 {\%}$ resistivity reduction when the NW cross-sectional area scales below $\sim 100 \text{nm}^{2}$ as compared to $\mu \mathrm{m}$-scale wires. Furthermore, resistivity of polycrystalline CoSi NWs with random grain orientations also approaches the theoretical CoSi bulk single-crystal resistivity limit when the NW cross-sectional area scales below $\sim 200 \text{nm}^{2}$. These results provide wafer-scale validation that topological conductors can enable interconnect scaling beyond Cu.

Despite constituting a smaller fraction of the qubit's electromagnetic mode, surfaces and interfaces can exert significant influence as sources of high-loss tangents, which brings forward the need to reveal properties of these extended defects and identify routes to their control. Here, we examine the structure and composition of the metal-substrate interfacial layer that exists in Ta/sapphire-based superconducting films. Synchrotron-based X-ray reflectivity measurements of Ta films, commonly used in these qubits, reveal an unexplored interface layer at the metal-substrate interface. Scanning transmission electron microscopy and core-level electron energy loss spectroscopy identified an intermixing layer (≈0.65 ± 0.05 nm) at the metal-substrate interface containing Al, O, and Ta atoms. Density functional theory modeling reveals that the structure and properties of the Ta/sapphire heterojunctions are determined by the oxygen content on the sapphire surface prior to Ta deposition for two atomic terminations of sapphire. Using a multimodal approach, we gained deeper insights into the interface layer between the metal and substrate, which suggests that the orientation of deposited Ta films depend on the surface termination of sapphire. The observed elemental intermixing at the metal-substrate interface influences the thermodynamic stability and electronic behavior of the film, which may also affect qubit performance.

In recent times the chiral semimetal cobalt monosilicide (CoSi) has emerged as a prototypical, nearly ideal topological conductor hosting giant, topologically protected Fermi arcs. Exotic topological quantum properties have already been identified in CoSi bulk single crystals. However, CoSi is also known for being prone to intrinsic disorder and inhomogeneities, which, despite topological protection, risk jeopardizing its topological transport features. Alternatively, topology may be stabilized by disorder, suggesting the tantalizing possibility of an amorphous variant of a topological metal, yet to be discovered. In this respect, understanding how microstructure and stoichiometry affect magnetotransport properties is of pivotal importance, particularly in case of low-dimensional CoSi thin films and devices. Here we comprehensively investigate the magnetotransport and magnetic properties of ≈25 nm Co1–xSix thin films grown on a MgO substrate with controlled film microstructure (amorphous vs textured) and chemical composition (0.40 < x < 0.60). The resistivity of Co1–xSix thin films is nearly insensitive to the film microstructure and displays a progressive evolution from metallic-like (dρxx/dT > 0) to semiconducting-like (dρxx/dT < 0) regimes of conduction upon increasing the silicon content. A variety of anomalies in the magnetotransport properties, comprising for instance signatures consistent with quantum localization and electron–electron interactions, anomalous Hall and Kondo effects, and the occurrence of magnetic exchange interactions, are attributable to the prominent influence of intrinsic structural and chemical disorder. Our systematic survey brings to attention the complexity and the challenges involved in the prospective exploitation of the topological chiral semimetal CoSi in nanoscale thin films and devices.

Gain-of-function mutations in the TRPV3 gene can cause Olmsted syndrome characterized by palmoplantar and periorificial keratoderma, itch, and hair loss. The mechanism underlying the hair loss remains unclear. In this study, we engineered an Olmsted syndrome mouse model by introducing the point mutation G568V to the corresponding Trpv3 locus in the mice. These mice developed fully penetrant hair loss. The hair loss was associated with premature differentiation of follicular keratinocytes characterized by precocious degeneration of trichohyalin and keratins, increased production of deiminated proteins, elevated apoptosis, and attenuation of transcription regulators (Foxn1, Msx2, Dlx3, and Gata3) known to regulate hair follicle differentiation. These abnormalities occurred in the medial.proximal region of the inner root sheath and the hair shaft, where Trpv3 is highly expressed, and correlated with an impaired formation of the hair canal and the hair shaft. The mutant Trpv3 mice also exhibited increased proliferation in the outer root sheath, accelerated hair cycle, reduction of hair follicle stem cells, and miniaturization of regenerated hair follicles. Findings from this study suggest that precocious maturation of postmitotic follicular keratinocytes drives hair loss in patients with Olmsted syndrome.

A novel nanosecond (ns) laser anneal (multiple laser shots at sub-melting low laser energy) was employed to reduce the blanket sheet resistance of Ru thin films deposited by physical vapor deposition (PVD). The laser anneal was conducted after PVD Ru deposition and then followed up with a standard 400°C anneal in a forming gas environment. Blanket sheet R decreased by 30% for the laser + furnace annealed Ru films, whereas the drop for just 400°C furnace annealed Ru films was only 18%. Multiple laser exposures at an optimized laser fluence was identified as a key factor in enabling this benefit at BEOL compatible thermal budget suitable for scaled-down Ru interconnects.

In situ characterization of the chemical and structural properties of black and white sheep hair was performed with a spatial resolution of 25 nm using infrared nano-spectroscopy. Comparing data sets from two types of hair allowed us to isolate the keratin FTIR fingerprint and so mark off chemical properties of the hair's melanosomes. From a polarization sensitive analysis of the nano-FTIR spectra, we showed that keratin intermediate filaments (IFs) present anisotropic molecular ordering. In stark contrast with white hair which does not contain melanosomes, in black hair, we spatially resolved single melanosomes and achieved unprecedented assignment of the vibrational modes of pheomelanin and eumelanin. The in situ experiment presented here avoids harsh chemical extractive methods used in previous studies. Our findings offer a basis for a better understanding of the keratin chemical and structural packing in different hair phenotypes as well as the involvement of melanosomes in hair color and biological functionality.

The interactions of mixtures of anionic and amphoteric surfactants with sugar amphiphiles were studied via high throughput small angle x-ray scattering (SAXS). The sugar amphiphile was composed of Caprate, Caprylate, and Oleate mixed ester of methyl glucoside, MeGCCO. Optimal surfactant interactions are sought which have desirable physical properties, which must be identified in a cost effective manner that can access the large phase space of possible molecular combinations. X-ray scattering patterns obtained via high throughput SAXS can probe a combinatorial sample space and reveal the incorporation of MeGCCO into the micelles and the molecular associations between surfactant molecules. Such data make it possible to efficiently assess the effects of the new amphiphiles in the formulation. A specific finding of this study is that formulations containing comparatively monodisperse and homogeneous surfactant mixtures can be reliably tuned by addition of NaCl, which swells the surfactant micelles with a monotonic dependence on salt concentration. In contrast, the presence of multiple different surfactants destroys clear correlations with NaCl concentration, even in otherwise similar series of formulations.

We have studied the origin of the exchange bias effect in the Au-Fe3O4 dumbbell nanoparticles in two samples with different sizes of the Au seed nanoparticles (4.1 and 2.7 nm) and same size of Fe3O4 nanoparticles (9.8 nm). The magnetization, small-angle neutron-scattering, synchrotron x-ray diffraction, and scanning transmission electron microscope measurements determined the antiferromagnetic FeO wustite phase within Fe3O4 nanoparticles, originating at the interface with the Au nanoparticles. The interface between antiferromagnetic FeO and ferrimagnetic Fe3O4 is giving rise to the exchange bias effect. The strength of the exchange bias fields depends on the interfacial area and lattice mismatch between both phases. We propose that the charge transfer from the Au nanoparticles is responsible for a partial reduction of the Fe3O4 into the FeO phase at the interface with Au nanoparticles. The Au-O bonds are formed, presumably across the interface to accommodate an excess of oxygen released during the reduction of magnetite

Human hair has three main regions, the medulla, the cortex and the cuticle. An existing model for the cortex suggests that the α-keratin- based intermediate filaments (IFs) align with the hair’s axis, but are orientationally disordered in-plane. We found that there is a new region in the cortex near the cuticle’s boundary in which the IFs are aligned with the hair’s axis, but additionally, they are orientationally ordered in-plane due to the presence of the cuticle/hair boundary. Further into the cortex, the IF arrangement becomes disordered, eventually losing all in-plane orientation. We also find that in the cuticle, a key diffraction feature is absent, indicating the presence of the β-keratin rather than that of the α-keratin phase. This is direct structural evidence that the cuticle contains β-keratin sheets. This work highlights the importance of using a sub-micron x-ray beam to unravel the structures of poorly ordered, multi-phase systems.

Helium implantation from transmutation reactions is a major cause of embrittlement and dimensional instability of structural components in nuclear energy systems. Development of novel materials with improved radiation resistance, which is of the utmost importance for progress in nuclear energy, requires guidelines to arrive at favorable parameters more efficiently. Here, we present a methodology that can be used for the design of radiation tolerant materials. We used synchrotron X-ray reflectivity to nondestructively study radiation effects at buried interfaces and measure swelling induced by He implantation in Cu/Nb multilayers. The results, supported by transmission electron microscopy, show a direct correlation between reduced swelling in nanoscale multilayers and increased interface area per unit volume, consistent with helium storage in Cu/Nb interfaces in forms that minimize dimensional changes. In addition, for Cu/Nb layers, a linear relationship is demonstrated between the measured depth-dependent swelling and implanted He density from simulations, making the reflectivity technique a powerful tool for heuristic material design.

A melange of hydroxyapatite and calcium phosphate hydrate coatings have been deposited on the surfaces of 316L type stainless steel and polyolefin (PP-PE), both components of 316L/PP-PE/316L sandwich, by an auto-catalytic route using an acidic bath. Coatings on 316L are made of spherules size ranged from 100 nm to 1 μm while those observed on PP-PE are smaller in the 50–600 nm range. Cell viability is much higher in samples with novel auto-catalytic layer of Ca–P than in the uncoated ones. Furthermore, our results show that the Ca–P coating produced by an auto-catalytic route act as promoter for osteoblasts proliferation. Osteoblasts morphology investigated by immunofluorescence proves that they are attached and well spread confirming the cytocompatibility.

Multifunctionality and improving the properties of materials make it necessary to use hybrid systems such as combinations of metals with polymers. Their applications can be found in all areas where light weight and improved and adapted mechanical properties as well as high functionality are needed. Moreover, tailored types of hybrids can be interesting for biomedical applications, as under specific conditions they show, e.g., good strength combined with high elasticity. Herein, we present preliminary tests on the biomimetic behavior of AISI SS316L/polypropylene copolymer/AISI SS316L sandwich. Biomimetic coatings were produced by inducing a calcium phosphate layer in a way similar to the process of natural bone formation. Knowledge of the formability of three-layered sandwich sheets and their biomimetic behavior is presented.

IR-806 is a near-infrared cyanine dye that forms assemblies in aqueous solutions which in turn orientationally order into a liquid crystal phase at concentrations as low as 0.5 wt %. Unlike many chromonic liquid crystals, the absorption spectrum of IR-806 changes dramatically with concentration, showing an isodesmic assembly process at lower :concentrations followed by a second process at higher concentration that is not isodesmic. The lower concentration assembly process is characterized by a free energy change per molecule of about 9 k(B)T, not unlike other chromonic systems. However, X-ray scattering measurements suggest that the assemblies that form during the higher concentration process are much larger than what is observed for many chromonic liquid crystals. Although there is a transitional region between the liquid crystal and isotropic phases of 10-15 degrees C, unlike most chromonic liquid crystals, no biphasic region is observed using polarizing microscopy.

We present the phase diagrams of electrostatically self-assembled amphiplexes (ESA) comprised of poly(acrylic acid) (PAA), cetyltrimethylammonium chloride (CTACl), dodecane, pentanol, and water at three different NaCl salt concentrations: 100, 300, and 500 mM. This is the first report of phase diagrams for these quinary complexes. Adding a cosurfactant, we were able to swell the unit cell size of all long-range ordered phases (lamellar, hexagonal, Pm3n, Ia3d) by almost a factor of 2. The added advantage of tuning the unit cell size makes such complexes (especially the bicontinuous phases) attractive for applications in bioseparation, drug delivery, and possibly in oil recovery.

The still undiscovered fluid ferroelectric nematic phase is expected to exhibit a much faster and easier response to an external electric field compared to conventional ferroelectric smectic liquid crystals; therefore, the discovery of such a phase could open new avenues in electro-optic device technology. Here, experimental evidence of a ferroelectric response to a switching electric field in a low molar mass nematic liquid crystal is reported and connected with field-induced biaxiality. The fluid is made of bent-core polar molecules and is nematic over a range of 120 degrees C. Combining repolarization current measurements, electro-optical characterizations, X-ray diffraction and computer simulations, ferroelectric switching is demonstrated and it is concluded that the response is due to field-induced reorganization of polar cybotactic groups within the nematic phase. This work represents significant progress toward the realization of ferroelectric fluids that can be aligned at command with a simple electric field.

In this paper we propose a detailed analysis of structural and morphological properties of two poly-L-lysine (PLL)-based transfection formulations, PLL/DNA and pegylated PLL (PLL-g-PEG)/DNA, by means of atomic force microscopy (AFM) and transmission electron microscopy (TEM). Comparing PLL-g-PEG/DNA with PLL/DNA polyplexes, we demonstrate that, due to the presence of PEG, the particles differ not only in size, shape, and crystalline structure, but also in transfection efficiency. While PLL condensates DNA in large agglomerates, PLL grafted with polyethylene glycol 2000 can condensate DNA in long filaments with diameters of some nanometers (6-20 nm). These structures are dependent on the grafting ratio and are more efficient than compacted ones, showing that DNA uptake and processing by cell is directly related to physicochemical properties of the polyplexes.

This article first defines the conditions a material implanted in a living organism has to fulfil to be considered as a biomaterial. It presents then some examples in which natural or synthetic polymers can be used either to coat the surface of an implant, with the aim to simultaneously reduce non specific protein adsorption and to favour specific cell adhesion, or in the form of a gel in order to induce recolonisation of a tissue in an injured region of a living organism. It finally shows that more efficient polymers for a given purpose can be synthesised with the tools of combinatorial chemistry.

We have carried out a detailed experimental study, by means of x-ray reflectometry (XRR) and half-leaky guided mode (HLGM) optical characterization, of the light-induced molecular adsorption and reorientation at the polyvinylcinnamate-fluorinated (PVCN-F)/liquid-crystal (LC) interface of a LC cell doped with the azo-dye methyl red (MR). The XRR data allowed characterizing the microscopic structure of the adsorbed dye layer both before irradiation (dark adsorption) and after irradiation (light-induced adsorption). The HLGM optical characterization has made possible the experimental determination of the nematic director profile in the LC cell and evaluation of the effects of light-induced adsorption on the LC anchoring conditions. The experimental findings have confirmed the formation of a dark-adsorbed layer and are in agreement with the absorption model previously proposed to account for the complex phenomenology related to light-induced anchoring and reorientation in dye-doped liquid crystals.

In-situ diffraction experiments were performed on SOFC under standard operating conditions, more specifically during successive cycles of reduction and reoxidation at ~ 850 °C.The experiment was performed with the spiral slit set-up at beamline ID15 at the ESRF and an X-ray wavelength of = 0.173 Å.The strain distribution within the three constituent layers of the SOFC was determined from the distortion of the monitored Debye-Scherrer-rings.

Abstract Coating technology is progressing at a steady rate with continuous significant improvements in the coatings performance. In the aerospace field, as well as in the stationary gas turbine field, coatings deposited by different processes (thermal spray, CVD, EBPVD) play an important role in order to increase the performances of the engines. In particular, in order to improve the resistance to oxidation and corrosion at high temperature, aluminium is deposited by several techniques (pack aluminising, above the pack and CVD) in alternative or addition to thermal spray coatings (mainly MCrAlY alloys where M stands for Co, Ni or CoNi). These MCrAlY coatings are generally deposited by Low Pressure Plasma Spray (LPPS) or Vacuum Plasma Spray (VPS), but also by High Velocity Oxygen Fuel (HVOF) and Air Plasma Spray (APS). This paper addresses the study of aluminium coatings deposited by CVD on CoNiCrAlY bond coats deposited by different processes: VPS with F4 gun, LPPS with EPI gun and HVOF. The aim is to verify if and how the different CoNiCrAlY coatings obtained by these three processes with different content of oxides and porosity could affect the deposition rate and quality of the Al coatings. The obtained samples have been characterized from the metallographic point of view in order to determine porosity, thickness and structure of both CoNiCrAlY and Al coatings. Al coating thickness has been taken as parameter in order to define the Al coating deposition rate on the three different CoNiCrAlY coatings. Further tests for the determination of aluminium content and chemical composition of the coatings are in progress.