Oxygen surface exchange kinetics and electronic conductivity of the third-order Ruddlesden-Popper phase Pr4Ni2.7Co0.3O10-δ

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Authors

  • Judith Lammer
  • Christian Gspan
  • Rotraut Merkle
  • Werner Grogger
  • Joachim Maier

Organisational units

External Organisational units

  • FELMI-ZFE Institut für Elektronenmikroskopie und Nanoanalytik - Zentrum für Elektronenmikroskopie
  • Institut für Elektronenmikroskopie und Nanoanalytik (FELMI), Technische Universität Graz
  • Technische Universität Graz
  • Max‐Planck‐Institut für Festkörperforschung, 70569 Stuttgart
  • Max Planck Institut für Festkörperforschung

Abstract

The third-order Ruddlesden-Popper phase Pr 4Ni 2.7Co 0.3O 10-δ (PNCO43) was synthesized by a freeze drying process. Phase purity and crystal structure were determined by X-ray diffraction and Rietveld analysis. The electronic conductivity of a bulk sample obtained by a two-step sintering process was measured by the four-point dc van der Pauw method as a function of temperature (50 ≤ T/°C ≤ 800) and oxygen partial pressure (1 × 10 3 ≤ pO 2/bar ≤1). Dense thin-film PNCO43 microelectrodes were prepared by pulsed laser deposition and photolithography on yttria-stabilised zirconia substrates. The thin-films were characterized by X-ray diffraction, scanning electron microscopy, scanning transmission electron microscopy, and inductively coupled plasma optical emission spectroscopy. Individual resistive and capacitive processes were investigated with electrochemical impedance spectroscopy as a function of the oxygen partial pressure (1 × 10 3 ≤ pO 2/bar ≤1) and temperature (600 ≤ T/°C ≤ 850). Oxygen surface exchange coefficients k q, calculated from the resistance of the electrode, show relatively high values (e.g. k q = 1.5 × 10 6 cm s −1 at 800 °C and 2 × 10 1 bar pO 2). Chemical surface exchange coefficients k chem of oxygen were obtained from the peak frequency or the chemical capacitance as determined by impedance spectroscopy.

Details

Original languageEnglish
Article number115282
JournalSolid State Ionics
Volume2020
Issue number348
DOIs
Publication statusPublished - 1 May 2020