High oxide-ion conductivity in acceptor-doped Bi-based perovskites at modest doping levels

Abstract

A combination of Impedance Spectroscopy, Time-of-Flight Secondary Ion Mass Spectrometry and literature data are used to show that, (i) the bulk oxide ion conductivity of A-site, alkaline earth-doped BiFeO3 (BF)...

Re-entrant relaxor ferroelectric behaviour in Nb-doped BiFeO3–BaTiO3 ceramics

“…According to recent research on BiFeO 3 -based ceramics, the low- and high-temperature regions may correspond to predominantly electronic and ionic conduction regimes respectively. 43 In summary, the substitution of Nb 5+ for Ti 4+ as a donor dopant in BF–BT ceramics suppresses the extrinsic p-type conductivity, which facilitates the poling procedure and induces piezoelectric properties that remain relatively stable for temperatures up to ∼400 °C.…”

“…The origin of the high conductivity in BF-BT is commonly attributed to the presence of oxygen vacancies introduced due to volatilisation of bismuth oxide during sintering and the subsequent reoxidation on cooling, with associated formation of free electron holes. 6,7 To address this issue, use of sintering additives and donor dopants or annealing in a reducing atmosphere have been reported to suppress the p-type electronic conductivity of BF-BT ceramics. 8,9 Enhanced piezoelectric properties can also be achieved through quenching processes, during which the sintered ceramic pellets are cooled rapidly from elevated temperatures (700-1000 1C) to room temperature in air or water.…”

Temperature-Dependent Ferroelectric Properties and Aging Behavior of Freeze-Cast Bismuth Ferrite–Barium Titanate Ceramics

“…The loss of bismuth oxide creates V Bi ‴ and V O •• charged defects during sintering. The oxygen vacancies, V O •• , mainly originate from bismuth loss and the conversion of Fe 3+ into Fe 2+ . Presence of V Bi ‴ and V O •• defects leads formation to defect dipoles that are aligned with the P s direction and likely pinned to the domain wall boundaries.…”

“…The oxygen vacancies, V O •• , mainly originate from bismuth loss and the conversion of Fe 3+ into Fe 2+ . 60 Presence of V Bi ‴ and V O •• defects leads formation to defect dipoles that are aligned with the P s direction and likely pinned to the domain wall boundaries. Oxygen vacancies are evident in both porous and dense samples, as shown in Figure 4 .…”

The effect of Sr substitution on the structural and physical properties of manganite perovskites Ca1−xSrxMnO3−δ (0 ≤ x ≤ 1)

“…In the last few decades, these materials have attracted great scientific and technological interest due to the possibilities of tuning their physical and chemical properties to meet the technological requirement for different applications on a large scale, e.g. gas sensors, 1 solid oxide fuel cells, [2][3][4][5][6] batteries, [7][8][9][10] photocatalysis, 11-13 catalysis [14][15][16] and photovoltaics. 17 Among these perovskite materials, CaMnO 3 (CMO) has great potential to be used as an anode material for Li-ion batteries owing to its unique features of cost effectiveness, good structural variability and high specific capacity (225.4 mA h g À1 ) after 90 cycles at standard temperature.…”