Tailoring Nonstoichiometry and Mixed Ionic Electronic Conductivity in Pr0.1Ce0.9O2-δ/SrTiO3 Heterostructures

George F. Harrington, Dmitri Kalaev, Bilge Yildiz, Kazunari Sasaki, Nicola H. Perry, Harry L. Tuller

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The oxygen deficiency or excess, as reflected in the nonstoichiometry of oxide films, plays a crucial role in their functional properties for applications such as micro solid oxide fuel cells, catalysis, sensors, ferroelectrics, and memristors. High concentrations of oxygen vacancies may be beneficial or detrimental according to the application, and hence there is interest in controlling the oxygen content of films without resorting to compositional changes. Here, we demonstrate that substantial changes in the nonstoichiometry of Pr0.1Ce0.9O2-δ (PCO), a model mixed ionic electronic conductor, can be achieved by fabricating multilayers with an inert material, SrTiO3 (STO). We fabricated heterostructures using pulsed laser deposition, keeping the total thickness of PCO and STO constant while varying the number of layers and thickness of each individual layer, to probe the effects of the PCO/STO interfaces. Conductivity measurements as a function of oxygen partial pressure (PO2 ) and temperature showed a significant weakening of the PO2 dependence compared to bulk PCO, which scaled with the density of interfaces. We confirmed that this change was due to variations in nonstoichiometry, by optical transmission measurements, and show that the lower oxygen content is consistent with a decrease in the effective oxygen reduction enthalpy of PCO. These results exemplify the dramatic differences in properties between films and their bulk counterparts, achievable by interface engineering, and provide generalized insight into tailoring the properties of mixed ionic electronic conductors at the nanoscale.

元の言語英語
ページ(範囲)34841-34853
ページ数13
ジャーナルACS Applied Materials and Interfaces
11
発行部数38
DOI
出版物ステータス出版済み - 9 25 2019

All Science Journal Classification (ASJC) codes

  • Materials Science(all)

フィンガープリント Tailoring Nonstoichiometry and Mixed Ionic Electronic Conductivity in Pr<sub>0.1</sub>Ce<sub>0.9</sub>O<sub>2-δ</sub>/SrTiO<sub>3</sub> Heterostructures' の研究トピックを掘り下げます。これらはともに一意のフィンガープリントを構成します。

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