Scheelite type Sr1−xBaxWO4 (x = 0.1, 0.2, 0.3) for possible application in Solid Oxide Fuel Cell electrolytes

Abstract

Polycrystalline scheelite type Sr 1−x Ba x WO 4 (x = 0.1, 0.2 & 0.3) materials were synthesized by the solid state sintering method and studied with respect to phase stability and ionic conductivity under condition of technological relevance for SOFC applications. All compounds crystallized in the single phase of tetragonal scheelite structure with the space group of I4 1 /a. Room temperature X-ray diffraction and subsequent Rietveld analysis confirms its symmetry, space group and structural parameters. SEM illustrates the highly dense compounds. Significant mass change was observed to prove the proton uptake at higher temperature by TG-DSC. All compound shows lower conductivity compared to the traditional BCZY perovskite structured materials. SBW with x = 0.3 exhibit the highest ionic conductivity among all compounds under wet argon condition which is 1.9 × 10 −6 S cm −1 at 1000 °C. Since this scheelite type compounds show significant conductivity, the new series of SBW could serve in IT-SOFC as proton conducting electrolyte.

Tetrahedral Displacive Disorder in the Scheelite-Type Oxide RbReO4

“…Scheelite-structured oxides have been identified as versatile functional materials due to their diverse range of physical and electronic properties, such as photocatalysis, luminescence, unusual magnetism, and ferroelasticity. − The scheelite structure has been identified as a means to develop electronically insulating solid electrolytes with competitive ionic conductivity for use in solid-oxide fuel cells. , Scheelites have also found application in nuclear waste management. , …”

“…1−4 The scheelite structure has been identified as a means to develop electronically insulating solid electrolytes with competitive ionic conductivity for use in solid-oxide fuel cells. 5,6 Scheelites have also found application in nuclear waste management. 7,8 The scheelites are a family of compounds with the chemical formula ABO 4 .…”

High-Pressure Properties of Wolframite-Type ScNbO4

“…During the past decade, ternary MTO 4 oxides have attracted great interest from both fundamental and applied research. − However, understanding of their responses to the application of pressure and other external fields is not fully known. Fundamental research is motivated by the need to systematically understand the properties of these compounds and their relationship with chemical bonding. − On the other hand, from the application point of view, many studies are driven by the multiple technological applications of MTO 4 oxides, which range from photocatalytic applications to uses as laser host and scintillating materials. − Among MTO 4 oxides, one of the most interesting groups is formed by wolframite-type compounds . These ternary oxides are isomorphic to natural iron manganese tungstate, the mineral wolframite.…”

Ruddlesden–Popper-Structured (Pr0.9La0.1)2(Ni0.8Cu0.2)O4+δ: An Effective Oxygen Electrode Material for Proton-Conducting Solid Oxide Electrolysis Cells

“…Proton defects can be formed in the oxide through the Wagner hydration mechanism, as shown in eq Water molecules combine with oxygen vacancies to produce two movable protons in the anion sublattice, and the protons combine with oxygen ions to form hydroxide defects . In a hydrated environment, the mass increases due to the absorption of water molecules, which leads to a significant increase in the proton concentration . The O 1s XPS spectrum of PLNCu is presented in Figure c.…”

“…23 In a hydrated environment, the mass increases due to the absorption of water molecules, which leads to a significant increase in the proton concentration. 24 The O 1s XPS spectrum of PLNCu is presented in Figure 3c. The peak at 529.2 eV is attributed to the lattice oxygen (O α ), while the peak at 532 eV is related to the surface oxygen (O β ).…”