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High-temperature polymer-electrolyte membrane fuel cells (HT-PEMFCs) are a very important type of fuel cells since they operate at 150–200 °C, making it possible to use hydrogen contaminated with CO. However, the need to improve the stability and other properties of gas-diffusion electrodes still impedes their distribution. Self-supporting anodes based on carbon nanofibers (CNF) are prepared using the electrospinning method from a polyacrylonitrile solution containing zirconium salt, followed by pyrolysis. After the deposition of Pt nanoparticles on the CNF surface, the composite anodes are obtained. A new self-phosphorylating polybenzimidazole of the 6F family is applied to the Pt/CNF surface to improve the triple-phase boundary, gas transport, and proton conductivity of the anode. This polymer coating ensures a continuous interface between the anode and proton-conducting membrane. The polymer is investigated using CO2 adsorption, TGA, DTA, FTIR, GPC, and gas permeability measurements. The anodes are studied using SEM, HAADF STEM, and CV. The operation of the membrane–electrode assembly in the H2/air HT-PEMFC shows that the application of the new PBI of the 6F family with good gas permeability as a coating for the CNF anodes results in an enhancement of HT-PEMFC performance, reaching 500 mW/cm2 at 1.3 A/cm2 (at 180 °C), compared with the previously studied PBI-O-PhT-P polymer. [ABSTRACT FROM AUTHOR]

An effect of Cu powder dispersion and morphology on the surface structure and the physical–chemical and catalytic properties of Cu–CeO2 catalysts prepared by mechanochemical synthesis was studied in the preferential CO oxidation in a H2-rich stream (CO-PROX). Two catalysts, produced by 30 min ball-milling from CeO2 and 8 mass% of copper powders and with particle sizes of several tens (dendrite-like Cu) and 50–200 nm (spherical Cu obtained with levitation-jet method), respectively, were characterized by X-ray diffraction and electron microscopy methods, a temperature-programmed reduction with CO and H2, and with Fourier-transform infrared spectroscopy. The catalyst synthesized from the "large-scale" dendrite-like Cu powder, whose surface consisted of CuxO (Cu+) agglomerates located directly on the surface of facetted CeO2 crystals with a CeO2(111) and CeO2(100) crystal planes exposition, was approximately two times less active at 120–160 °C than the catalyst synthesized from the fine Cu powder, whose surface consisted of CuxO (Cu2+) clusters of 4–6 nm in size located on the steps of facetted CeO2 nanocrystals. Although a large part of CO2 reacted with a ceria surface to give carbonate-like species, no blockage of CO-activating centers was observed due to the surface architecture. The surface structure formed by the use of highly dispersed Cu powder is found to be a key factor responsible for the catalytic activity. [ABSTRACT FROM AUTHOR]

Conductive LaNiO3 (LNO) films with an ABO3 perovskite structure deposited on silicon wafers are a promising material for various electronics applications. The creation of a well-defined columnar grain structure in CSD (Chemical Solution Deposition) LNO films is challenging to achieve on an amorphous substrate. Here, we report the formation of columnar grain structure in LNO films deposited on the Si-SiO2 substrate via layer-by-layer deposition with the control of soft-baking temperature and high temperature annealing time of each deposited layer. The columnar structure is controlled not by typical heterogeneous nucleation on the film/substrate interface, but by the crystallites' coalescence during the successive layers' deposition and annealing. The columnar structure of LNO film provides the low resistivity value ρ~700 µOhm·cm and is well suited to lead zirconate-titanate (PZT) film growth with perfect crystalline structure and ferroelectric performance. These results extend the understanding of columnar grain growth via CSD techniques and may enable the development of new materials and devices for distinct applications. [ABSTRACT FROM AUTHOR]

The microstructure and local structural analysis of undoped and strontium‐doped lanthanum scandates are performed by means of electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) on dense ceramic specimens. LaScO3 is found to be homogeneous: there are no impurities and all the grains in the polycrystalline sample are structurally uniform and described in the framework of the same structural model of orthorhombic perovskite (space group Pnma). However, the existence of structural inhomogeneity in a polycrystalline sample of the La0.91Sr0.09ScO3–δ oxide is revealed and described. Possible reasons for the structural inhomogeneities are considered. [ABSTRACT FROM AUTHOR]

Porous ferroelectric lead zirconate–titanate (PZT) films with different internal structures are synthesized using a sol–gel technique and spin‐on deposition on platinized silicon substrates. The films' porosity is engineered using various structure‐directing agents: polyvinylpyrrolidone with a molecular weight of 360 000 (1–6.6 wt.%) and block copolymer surfactants Brij 30 and Brij 76 (30–60 wt.%). The films' structures are characterized by transmission electron microscopy. The PVP‐based films contain large, elongated pores with diameters as large as 100 nm. By contrast, the films prepared from solutions with block copolymers exhibit a small pore size depending on the surfactant molecular weight (10–19 nm for Brij 30 and 20–27 nm for Brij 76), with a mostly uniform distribution of channel‐like pores within the film volume. Despite their highly porous structures, all of the films show a columnar‐grain perovskite structure with grains as large as several micrometers and curved grain boundaries. The films demonstrate ferroelectric behavior with dielectric hysteresis, and their permittivity decreases with increasing porosity. Thus, the Brij 30 and Brij 76 copolymer surfactants can be used to engineer fine porous structures in PZT films for various applications in electronics. [ABSTRACT FROM AUTHOR]

The paper presents results of investigation of Fe65.3–100Zr34.7–0N7.5–0 films prepared by dc magnetron deposition on glass substrates and subsequent 1-hour annealing at temperatures of 300–600 °C. The influence of the chemical and phase compositions and structure of the films, which were studied by TEM, SEM, XRD, and GDOES, on their mechanical properties determined by nanoindentation and static magnetic properties measured by VSM method is analyzed. The studied films exhibit the hardness within a range of 14–21 GPa, low elastic modulus (the value can reach 156 Gpa), and an elastic recovery of 55–83%. It was shown that the films are strong ferromagnets with the high saturation induction Bs (up to 2.1 T) and low coercive field Hc (as low as 40 A/m). The correlations between the magnetic and mechanical properties, on one hand, and the chemical composition of the films, their phase, and structural states as well, on the other hand, are discussed. [ABSTRACT FROM AUTHOR]