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Core-shell structured amorphous FeSiBCr@phosphate/silica powders were prepared by phosphating and sodium silicate treatment. The soft magnetic composites (SMCs) were fabricated based on these powders. The effects of phosphoric acid (H₃PO₄) concentration and annealing temperature on their properties were investigated. During the phosphating process, the powder coated with a low concentration of H₃PO₄-ethanol solution leads to uneven phosphate coating, while the peeling of phosphate coating occurs for the high H₃PO₄ concentration. Using 0.5 wt.% phosphoric solution, a uniform and dense insulation layer can be formed on the surface of the powder, resulting in increased resistivity and the reduced eddy current loss of the amorphous soft magnetic composites (ASMCs). This insulation layer can increase the roughness of the powder surface, which is beneficial to the subsequent coating of sodium silicate. By optimizing sodium silicate treatment, a complete and uniform SiO₂ layer can be formed on the phosphated powders well, leading to double layer core-shell structure and excellent soft magnetic properties. The magnetic properties of amorphous SMCs can be further improved by post annealing due to the effectively released residual stress. The enhanced permeability and greatly reduced core loss can be achieved by annealing at 773 K, but the deterioration of magnetic properties occurs as the annealing temperature over 798 K, mainly due to the increase of α-Fe(Si) and Fe₃B phases, which hinder the domain wall displacement and magnetic moment rotation. The excellent soft magnetic properties with permeability μ_e = 35 and core loss P_s = 368 kW/m³ at 50 mT/200 kHz have been obtained when the SMCs prepared with the powders coated by 0.5 wt.% H₃PO₄ and 2 wt.% sodium silicate were annealed at 773 K. Full article

CsH₂PO₄ is a proton conductor pertaining to the acid salts group and shows a phase transition from monoclinic to cubic phase at 232 ± 2 °C under high-steam atmospheres (>30%). This cubic phase gives rise to the so-called superprotonic conductivity. In this work, the influence of the partial substitution of Cs by Ba and Rb, as well as the partial substitution of P by W, Mo, and S in CsH₂PO₄ on the phase transition temperature and electrochemical properties is studied. Among the tested materials, the partial substitution by Rb led to the highest conductivity at high temperature. Furthermore, Ba and S-substituted salts exhibited the highest conductivity at low temperatures. CsH₂PO₄ was used as electrolyte in a fully-assembled fuel cell demonstrating the applicability of the material at high pressures and the possibility to use other materials (Cu and ZnO) instead of Pt as electrode electrocatalyst. Finally, an electrolyzer cell composed of CsH₂PO₄ as electrolyte, Cu and ZnO as cathode and Pt and Ag as anode was evaluated, obtaining a stable production of H₂ at 250 °C. Full article