We describe methodologies for the generation and screening of combinatorial libraries of electrocatalyst materials for fuel cell applications, generated by cosputtering of three elements onto a Si substrate coated with a Ta adhesion underlayer. Screening was carried out via a fluorescence assay as well as by scanning electrochemical microscopy. Whereas the former provided rapid qualitative screening with limited spatial resolution, the latter provided high spatial resolution. The fluorescence screening method was tested on Pt, PtBi, PtPb, and PtRu nanoparticles, while both methods were tested on a film containing a Pt–Bi–Pb ternary composition spread.

Novel-morphological Fe3O4 nanosheets with magnetochromatic property have been prepared by a modified solvothermal method. Such nanosheets could form one-dimension photonic crystal under an external magnetic field. The Fe3O4 nanosheets suspension could strongly diffract visible light and display varied colors with changing the intensity of the magnetic field. The photonic response is rapid, fully reversible and widely tunable in the entire visible spectrum. Excellent magnetic properties of these Fe3O4 nanosheets are exhibited with a high saturation magnetization (82.1 emu/g), low remanence (13.85 emu/g) and low coercive force (75.95 Oe). The amount of the solvent diethylene glycol (DEG) plays a key role in the formation of the sheet-shaped morphology. When the ratio of the DEG reaches 100%, the growing of the crystal plane (111) of Fe3O4 is inhibited and the sheet-like Fe3O4 crystals are formed.

Functional nanoscale coordination polymers are receiving growing scientific interest because of their potential applications in many domains. In this paper, we demonstrated that a nanofibrous networked metal-organic gel (G1-MNPs) was formed by simply mixing 4,4',4''-(1,3,5-triazine-2,4,6-triyl)tris(N-(pyridin-3-ylmethyl)benzamide) (L) and Pd(COD)(NO(3))(2) in CHCl(3)-MeOH with a Pd/L molar ratio of 1:1 in the presence of magnetite nanoparticle (MNPs). The self-assembly behavior of nanofibers was not significantly effected by the introduction of magnetite nanoparticles. The xerogel of G1-MNPs was superparamagnetic and showed catalytic activity in Suzuki-Miyaura C-C coupling reactions. The Pd(II) xerogel could be magnetically isolated and recycled with a permanent magnet. It represents a novel strategy to introduce nanoparticles into functional coordination polymers for multifunctional materials.

New 7xxx aluminum alloys with high alloying contents are being designed, which could induce serious hot tearing defects during direct-chill (DC) casting. Among all factors affecting hot tearing of 7xxx alloys, undoubtedly alloying elements play a significant role. In this study, the effect of main alloying elements (Zn, Mg, and Cu) on hot tearing of grain-refined Al-xZn-yMg-zCu alloys was investigated by a dedicated hot tearing rating apparatus simulating the DC-casting process. It was found that the minimum and maximum hot tearing susceptibilities occur for 4 to 6 and 9 wt pct Zn, respectively, indicating the complicated effect of Zn content. The hot tearing resistance of grain-refined Al-9Zn-yMg-zCu alloys is enhanced with increasing Mg content but is deteriorated with increasing Cu content. This can be attributed to the interaction of the thermal stresses, melt feeding, and final eutectics. The observed tendencies of the main alloying elements on hot tearing were also confirmed for four commercial 7xxx alloys. In addition, both the load value at non-equilibrium solidus and the SKK criterion proposed by Suyitno et al. using measured load developments were found to be good indicators in predicting hot tearing susceptibility. This study can provide a beneficial guide in designing 7xxx alloys considering the potential occurrence of hot cracks beforehand.

Transition metal dichalcogenides (TMDs) are promising for spintronic devices owing to their spin-orbit coupling and loss of inversion symmetry. However, further development was obstructed by their intrinsic nonmagnetic property. Doping TMDs with non-metal light atoms has been predicted to be a good option to induce unexpected magnetic properties which remain rarely explored. Here, we utilize nitrogen doping to introduce magnetic domains into anisotropic ReS 2 , giving rise to a transition from nonmagnetic to tunable magnetic ordering. Both of the experimental and computational results confirmed that the N-doping in ReS 2 prefers to take place at the edge site than in-plane site. With controlled doping concentration, it exhibits a unique ferromagnetic-antiferromagnetic (FM-AFM) coupling. Assisted by theoretical calculations, we demonstrated that FM-AFM coupling presents a strong link to doping contents and doping sites. Wherein, the FM ordering mostly comes from N atoms and the AFM ordering originate from Re atoms. At the N-doping content of 4.24%, the saturated magnetization of N-doped ReS 2 reached the largest value of 2.1 emu g −1 at 2 K. Further altering the content to 6.64%, the saturated magnetization of N-doped ReS 2 decreases, but exhibits a distinct exchange bias (EB) phenomenon of around 200 Oe. With controlled N-doping concentrations, the intrinsic spin in ReS 2 could be well altered and resulted in distinct magnetism, presenting tremendous potential for spintronic devices in information storage.

We report a spin-orbit coupling induced back-action cooling in an optomechanical system, composed of a spin-orbit coupled Bose-Einstein condensate trapped in an optical cavity with one movable end mirror, by suppressing heating effects of quantum noises. The collective density excitations of the spin-orbit coupling mediated hyperfine states -serving as atomic oscillators equally coupled to the cavity field -trigger strongly driven atomic back-action. We find that the back-action not only revamps low-temperature dynamics of its own but also provides an opportunity to cool the mechanical mirror to its quantum mechanical ground state. Further, we demonstrate that the strength of spin-orbit coupling also superintends dynamic structure factor and squeezes nonlinear quantum noises, like thermo-mechanical and photon shot noise, which enhances optomechanical features of hybrid cavity beyond the previous investigations. Our findings are testable in a realistic setup and enhance the functionality of cavity-optomechanics with spin-orbit coupled hyperfine states in the field of quantum optics and quantum computation.

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We presented a method to use SiO2/SiNx:H double layer antireflection coatings (DARC) on acid textures to fabricate colored multicrystalline silicon (mc-Si) solar cells. Firstly, we modeled the perceived colors and short-circuit current density (Jsc) as a function of SiNx:H thickness for single layer SiNx:H, and as a function of SiO2thickness for the case of SiO2/SiNx:H (DARC) with fixed SiNx:H (refractive indexn=2.1at 633 nm, and thickness = 80 nm). The simulation results show that it is possible to achieve various colors by adjusting the thickness of SiO2to avoid significant optical losses. Therefore, we carried out the experiments by using electron beam (e-beam) evaporation to deposit a layer of SiO2over the standard SiNx:H for156×156 mm2mc-Si solar cells which were fabricated by a conventional process. Semisphere reflectivity over 300 nm to 1100 nm andI-Vmeasurements were performed for grey yellow, purple, deep blue, and green cells. The efficiency of colored SiO2/SiNx:H DARC cells is comparable to that of standard SiNx:H light blue cells, which shows the potential of colored cells in industrial applications.