Modifying grain boundary ionic/electronic transport in nano-Sr- And Mg- Doped LaGAO3-δ by sintering variations

Ting Chen, George F. Harrington, Junko Matsuda, Kazunari Sasaki, David Pham, Erica L. Corral, Nicola H. Perry

研究成果: Contribution to journalArticle査読

4 被引用数 (Scopus)

抄録

Perovskite La0.9Sr0.1Ga0.9Mg0.1O3-δ (LSGM) is one of the fastest known oxide ion conductors, with reported enhanced p-type electronic transference numbers at grain boundaries, attributed to space charge effects. As this material is applied as a solid oxide fuel/electrolysis cell electrolyte, it is of interest to learn how its mixed conductivity may be tailored. Field assisted sintering technique/spark plasma sintering (FAST/SPS) and conventional sintering without field or pressure were employed to prepare pellets with various grain sizes, in order to systematically assess the influence of processing route on the mixed conductivity. AC-impedance spectroscopy and the brick layer model were applied to determine local conductivities as a function of temperature, oxygen partial pressure, and dc bias. With increasing sintering temperature and grain size, the following trends were observed: larger electrical grain boundary (GB) widths, higher GB potentials, lower specific GB conductivity, greater dc-bias dependence of GB conductivity, higher pO2-dependence of GB conductivity indicating higher electronic transference numbers, and lower pre-exponential factor for specific GB conductivity. These results suggest an increasing GB space charge effect with increasing sintering temperature/grain size, which coincided with increasing compositional uniformity by TEM and EDS. The results confirm that sintering route is an important variable for tailoring mixed conduction.

本文言語英語
ページ(範囲)F569-F580
ジャーナルJournal of the Electrochemical Society
166
10
DOI
出版ステータス出版済み - 2019

All Science Journal Classification (ASJC) codes

  • 電子材料、光学材料、および磁性材料
  • 再生可能エネルギー、持続可能性、環境
  • 表面、皮膜および薄膜
  • 電気化学
  • 材料化学

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