Phys.org October 30, 2023 Transition-metal oxides (TMOs) with strong ferrimagnetism provide new platforms for tailoring the anomalous Hall effect (AHE) beyond conventional concepts based on ferromagnets, and particularly TMOs with perpendicular magnetic anisotropy (PMA) are of prime importance for today’s spintronics. In this study researchers in Germany reported on transport phenomena and magnetic characteristics of the ferrimagnetic TMO NiCo2O4 (NCO) exhibiting PMA. The entire electrical and magnetic properties of NCO films were strongly correlated with their conductivities governed by the cation valence states. The AHE exhibited an unusual sign reversal resulting from a competition between intrinsic and extrinsic mechanisms depending […]
Tag Archives: S&T Germany
Novel approach towards nanomaterials developed
Nanowerk September 25, 2023 In a typical approach for creating nanostructures ligands are grafted onto the surfaces of nanoparticles to improve the dispersion stability and control interparticle interactions. Ligands remain secondary and usually are not expected to order significantly during superstructure formation. Researchers in Germany investigated how ligands can play a more decisive role in the formation of anisotropic inorganic–organic hybrid materials. They grafted poly(2-iso-propyl-2-oxazoline) (PiPrOx) as a crystallizable shell onto SiO2 nanoparticles. By varying the PiPrOx grafting density, both solution stability and nanoparticle aggregation behavior could be controlled. Upon prolonged heating, anisotropic nanostructures formed in conjunction with the crystallization […]
A linear path to efficient quantum technologies
Nanowerk September 12, 2023 Bell-state projections serve as a fundamental basis for most quantum communication and computing protocols today. However, with current Bell-state measurement schemes based on linear optics, only two of four Bell states can be identified, which means that the maximum success probability of this vital step cannot exceed 50%. Researchers in Germany experimentally demonstrated a scheme that amended the original measurement with additional modes in the form of ancillary photons, which led to a more complex measurement pattern, and ultimately a higher success probability of 62.5%. Experimentally, they achieved a success probability of (57.9 ± 1.4)%, a […]
Microscopic transformations of electrocatalyst surfaces
Nanowerk August 18, 2023 Potentiodynamic methods that induce structural changes in Cu catalysts for the electrochemical reduction of CO2 (CO2RR) have been identified as a promising strategy for steering the catalyst selectivity towards the generation of multi-carbon products. In the current approaches, active species are created via a sequential Cu oxidation–reduction process. Researchers in Germany have shown that low-coordinated Cu surface species form spontaneously near the onset of CO2 electrocatalytic reduction. This process started by CO-induced Cu nanocluster formation in the initial stages of the reaction, led to irreversible surface restructuring that persisted over a wide potential range. On subsequent […]
New property of hydrogen predicted
Phys.org August 7, 2023 Recently it was predicted based on ab initio quantum Monte Carlo simulations that, in a uniform electron gas, the peak ω0 of the dynamic structure factor S(q,ω) exhibits an unusual nonmonotonic wave number dependence, where dω0/dq<0, at intermediate q, under strong coupling conditions. Researchers in Germany predicted that this nonmonotonic dispersion resembling the roton-type behavior known from superfluids should be observable in a dense, partially ionized hydrogen plasma. Based on a combination of path integral Monte Carlo simulations and linear response results for the density response function, they presented the approximate range of densities, temperatures and […]
Self-healing plastic becomes biodegradable
Science Daily July 27, 2023 Mineral plastics are a promising class of bio-inspired materials that have properties, like self-heal ability, stretchability, hardness, and non-flammability, they can be reshaped easily. However, current mineral plastics are hardly biodegradable, and thus persistent in nature. Researchers in Germany have developed the next generation of mineral plastics, which are bio-based and biodegradable. Physically cross-linked (poly)glutamic-acid (PGlu)-based mineral plastics using various alcohol-water mixtures, metal ion ratios and molecular weights. The rheological properties were easily adjusted using these parameters. The general procedure involved addition of equimolar solution of CaCl2 to PGlu in equal volumes followed by addition […]
Intelligent rubber materials
Nanowerk July 18, 2023 Researchers in Germany have developed intelligent humidity-programmed hydrogel patches with high stretchability and tunable water-uptake and -release by copolymerization and crosslinking of N-isopropylacrylamide and oligo(ethylene glycol) comonomers. The intelligent elastomeric patches strongly responded to different humidities and temperatures in terms of mechanical properties which made them applicable for soft robotics and smart skin applications where autonomous adaption to environmental conditions was a key requirement. Beyond using the hydrogel in the conventional state in aqueous media, the new patches could be controlled by relative humidity. The humidity programming of the patches allowed to tune drug release kinetics, […]
Satellite security lags decades behind the state of the art
Science Daily July 11, 2023 Despite its critical importance, little academic research has been conducted on satellite security and the security of onboard firmware. This lack likely stems from by now outdated assumptions on achieving security by obscurity, effectively preventing meaningful research on satellite firmware. Researchers in Germany have provided a taxonomy of threats against satellite firmware and conducted an experimental security analysis of three real-world satellite firmware images. They based their analysis on a set of real-world attacker models and found several security-critical vulnerabilities in all analyzed firmware images. The results showed that modern in-orbit satellites suffer from different […]
Fear of being exploited is stagnating our progress in science, say researchers
Phys.org June 27, 2023 Knowledge hiding in academia—the reluctance to share one’s ideas, materials, or knowledge with other researchers—is detrimental to scientific collaboration and harms scientific progress. In three studies, researchers in Germany tested whether (a) knowledge hiding could be predicted by researchers’ latent fear of being exploited (i.e., victim sensitivity), whether (b) this effect was mediated by researchers’ suspiciousness about their peers, and whether (c) activating researchers’ social identity alleviated or rather amplified this effect. Study 1 showed that victim-sensitive researchers whose social identity as a “researcher” had been made salient were particularly prone to knowledge hiding. Study 2 […]
Nanophotonics: Coupling light and matter
Science Daily June 23, 2023 Photonic bound states in the continuum (BICs) provide a platform for strong light-matter coupling with transition metal dichalcogenides (TMDCs) but have so far mostly been implemented as traditional all-dielectric metasurfaces with adjacent TMDC layers, incurring limitations related to strain, mode overlap and material integration. Researchers in Germany demonstrated intrinsic strong coupling in BIC-driven metasurfaces composed of nanostructured bulk tungsten disulfide (WS2) and exhibiting resonances with sharp, tailored linewidths and selective enhancement of light-matter interactions. Tuning of the BIC resonances across the exciton resonance in bulk WS2 was achieved by varying the metasurface unit cells, enabling […]