Effect of Ti substitution for Nb in double perovskite-type Ba3CaNb2O9 on chemical stability and electrical conductivity

Ordering effect on the electrical properties of stoichiometric Ba3CaNb2O9-based perovskite ceramics

“…In this system, a percolation path of NbO 6 octahedra accounts the increase in the proton conductivity until x = 0.18. For x > 0.18, it is observed an increased activation energy, and then a decrease in the dc conductivity despite the high concentration of oxygen vacancies [17,64]. From our results above, we can conclude that the 1:1 ordering enhances the dc conductivity, but not enough to account the excellent performance reported for the nonstoichiometric barium calcium niobate ceramics.…”

“…]. The Thangadurai group has studied the partial replacement of Ba by K on A-site and Ti substitution for Nb in the stoichiometric Ba 3 CaNb 2 O 9 [16,17]; The Fanglin Chen group has reported the effects of Ce and Y doping on the Ca and Nb ions in complex perovskite Ba 3 Ca 1.18 Nb 1.82 O 9-δ proton conductor [9,18]. In all cases, the nonstoichiometry leads to a formation of oxygen vacancies and a modification in the B-site ordering from 1:2 to 1:1 type [19].…”

Challenges and prospects of anodes for solid oxide fuel cells (SOFCs)

“…To improve the electrochemical activity of BCN, partial substitution transition metal ions (Ti, Mn, Fe, Co) for Ca and/ or Nb ions were tested [76][77][78]. The detailed structural analysis and electrical properties of Ba 2 (Ca,Nb) 2-x M x O 6-δ (M = Mn, Fe, Co) was recently reported by Kan et al [76].…”

Novel Methods of Tritium Sequestration: High Temperature Gettering and Separation Membrane Materials Discovery for Nuclear Energy Systems

“…FTIR spectrum study also confirmed the water adsorption on boiled Ba 3 CaNb 1.75 Ti 0.25 O 9-δ samples as reported by Thangadurai. 44 The stability tests were also conducted in CO 2 atmosphere at 700 o C for 4 h as well as in wet 3 vol% CO 2 (air as the balance gas, 3 vol% H 2 O) at 700 o C for 24 h, both with a flow rate of 50 mL min -1 to evaluate the stability in carbon dioxide environments. XRD patterns of the samples after exposures are presented in Fig.…”

“…However, differences in brightness of the spots are indicative of a superlattice reflection due to the ordering of the structure. 37,38 The reconstruction of the reciprocal space from the SAED pattern leads to a superstructure of the cell, with a'=√2/2a as shown in Fig. 2.35(A).…”