Structure and transport properties of triple-conducting Ba_xSr_1−xTi_1−yFe_yO_3−δoxides

Abstract

BaxSr1−xTi1−yFeyO3−δ-based perovskite materials with different barium and iron contents are reported as triple conducting oxides (TCOs), which may conduct three charge carriers: oxygen ions, protons and electrons/holes.

Proton-Electron Hole Interactions in Sr(Ti,Fe)O3−δ Mixed-Conducting Perovskites

“…As has been discussed in our previous work, 24 and studies performed by Poetzsch et al 52 in the case of the materials with a high hole concentration the water is incorporated by hydrogenation reaction. In such a reaction, proton absorption can be carried out at the expense of holes.…”

“…16,22 Recent works have presented SrTi 1−x Fe x O 3−δ (STFx) solid solutions of SrTiO 3 and SrFeO 3, as potential candidates for efficient TCO. [23][24][25] It has been shown in our previous work, 23 that SrTi 1−x Fe x O 3−δ with the Fe content below x = 0.5 exhibits high proton concentration, whereas for a higher Fe content the proton concentration significantly decreases. For z E-mail: tadeusz.miruszewski1@pg.edu.pl example, the proton concentration in SrTi 0.9 Fe 0.1 O 2.8−δ at 400 °C was estimated as ∼5 × 10 −2 mol mol −1 , whereas in the samples with 50 mol% iron content the proton concentration was lower.…”

Water uptake kinetics and electrical transport in BaCe0.6Zr0.2Y0.1M0.1O3−δ (M = Tb, Pr, Fe) protonic conductors

“…in double perovskite cobaltite or doped Sr(Ti,Fe)O 3 solid solutions with a higher iron content. 27–29 Fig. 2 and 3 also show that after the switch from humidified to dry air, mass changes are much slower than those that occur after the switch from dry to humidified air.…”

Properties of Oxygen Vacancy and Hydrogen Interstitial Defects in Strontium Titanate: DFT + Ud,p Calculations

“…In recent years, STO has also become the subject of an increased interest in electrochemistry, as it has been demonstrated to be a good base material for the fabrication of the so-called triple-conducting oxides (TCOs). ,, These materials are capable of conducting oxygen (O 2– ) and hydrogen (H + ) ions, and electrons or holes, and are therefore considered promising for use as novel cathodes in proton-conducting fuel cells. , One of the examples of promising STO-based TCO is SrTi x Fe 1– x O 3−δ , which was found to be electrochemically stable, offering high ionic conductivity and good ion surface exchange rates. ,− …”

“…In the last few years, significant advances were made in the experimental studies focusing on the synthesis, testing, and application of various TCOs. − , However, their better understanding still requires considerable theoretical work because even the base materials are still poorly understood in the context of mixed electron-ion transport. This knowledge gap mainly originates from the difficulties encountered in theoretical modeling studies .…”