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Molten Na2CO3–K2CO3 (NKC, 56–44 mol%) eutectic compositions were vacuum‐impregnated, at the eutectic temperature, into two porous ZrO2:8.6 mol% MgO (magnesium‐partially stabilized zirconia, MgPSZ) and ZrO2:8 mol% Y2O2 (yttria‐fully stabilized zirconia, 8YSZ) ceramics. Thermogravimetric analyses were performed in mixtures of that composition with MgPSZ and 8YSZ ceramic powders. Before impregnation, porosity was achieved in the two compounds by addition and thermal removal of 30 vol.% NKC. To ascertain the carbonates had filled up through the ceramic body, both sides of the parallel and fracture surfaces of the disk‐shaped impregnated compositions were observed in a scanning electron microscope and analyzed by energy‐dispersive X‐ray spectroscopy. The electrical conductivity of the two ceramics, before and after impregnation, was evaluated by electrochemical impedance spectroscopy in the 5 Hz–13 MHz frequency range from approximately 530 to 740°C. The permeation of the carbonate ions through the membranes via the eutectic composition was assessed by the threshold temperatures of the onset of the carbonate ion percolation. The objectives were to prepare dual‐phase membranes for the separation of carbon dioxide and for the development of carbon dioxide sensors. [ABSTRACT FROM AUTHOR]

Cosintering (La0.84Sr0.16MnO3 thin‐film cathode/ZrO2: 8 mol% Y2O3 thin‐film solid electrolyte/55 vol.% ZrO2:8 mol% Y2O3 + 45 vol.% NiO anode, ϕ = 12 × 1.5 mm thick pellet) was achieved by applying an electric field for 5 min at 1200°C. Impedance spectroscopy measurements of the anode‐supported three‐layer cell show an improvement of the electrical conductivity in comparison to that of a conventionally sintered cell. The scanning electron microscopy images of the cross‐sections of electric field‐assisted pressureless sintered cells show a fairly dense electrolyte and porous anode and cathode. Joule heating, resulting from the electric current due to the application of the AC electric field, is suggested as responsible for sintering. Dilatometric shrinkage curves, electric voltage and current profiles, impedance spectroscopy diagrams, and scanning electron microscopy micrographs show how anode‐electrolyte‐cathode ceramic cells can be cosintered at temperatures lower than the usually required. [ABSTRACT FROM AUTHOR]

Electric field-assisted (flash) pressureless sintering experiments were carried out in ZrO ceramics doped with 10 mol% ScO and 1 mol% CeO (10Sc1CeSZ). All experiments were conducted isothermally at 1050 °C for 2-5 min with the application of a 100-150 V cm AC electric field at 1 kHz with 1-4 A limiting current in green compacts and in samples pre-sintered at different temperatures. Shrinkage level, structural phases and grain morphology data were collected by dilatometry, X-ray diffraction and scanning electron microscopy analyses, respectively. The results showed that for the same delivered electric power, the final shrinkage was higher for higher temperature applications of the electric field and for higher electric current pulses. Moreover, the higher the porosity, the higher the final densification of the flash-sintered 10Sc1CeSZ samples, showing that pores play a role as a preferential path in the flash sintering mechanism. [ABSTRACT FROM AUTHOR]