Development of a novel SIMS technique for oxygen self-diffusion and surface exchange coefficient measurements in oxides of high diffusivity

1992 ◽  
Vol 53-56 ◽  
pp. 859-867 ◽  
Author(s):  
R.J. Chater ◽  
S. Carter ◽  
J.A. Kilner ◽  
B.C.H. Steele
Keyword(s):  
Exchange Coefficient ◽  
Surface Exchange ◽  
Self Diffusion ◽  
Surface Exchange Coefficient

Oxygen self-diffusion in cerium oxide doped with Nd

2001 ◽  
Vol 16 (1) ◽  
pp. 179-184 ◽  
Author(s):  
Michiyo Kamiya ◽  
Eriko Shimada ◽  
Yasuro Ikuma ◽  
Manabu Komatsu ◽  
Hajime Haneda ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Oxygen Diffusion ◽  
Secondary Ion Mass Spectrometry ◽  
Diffusion Annealing ◽  
Exchange Coefficient ◽  
Surface Exchange ◽  
Oxygen Diffusion Coefficient ◽  
Self Diffusion ◽  
Surface Exchange Coefficient ◽  
Secondary Ion

Polycrystalline Ce0.77Nd0.23O1.885having a relative density in excess of 98% was prepared. Oxygen diffusion experiments were performed for the temperature range from 750 to 1100 °C, in an oxygen partial pressure of 6.6 kPa. The concentration profile of18O in the specimens following diffusion annealing was measured by secondary ion mass spectroscopy (SIMS). The oxygen self-diffusion coefficient obtained using secondary ion mass spectrometry was expressed by D = 6.31 × 10−9exp(−53 kJ mol−1/RT) m2s−1and was in the extrinsic region. The oxygen diffusion coefficient of Ce0.77Nd0.23O1.885was larger than that of Ce0.8Y0.2O1.90; it was close to those of Ce0.6Y0.4O1.80and Ce0.69Gd0.31O2−δ. The oxygen diffusion coefficient obtained by the tracer method at 700 °C agreed with that calculated from the electrical conductivity in Ce0.77Nd0.23O1.885. The activation energy of the surface exchange coefficient was 94 kJ mol−1, and the values of the surface exchange coefficient were similar to those of stoichiometric CeO2and ThO2.

A Study of the Oxygen Surface Exchange Coefficient on La0.5Sr0.5CoO3−δ Thin Films

1999 ◽  
Vol 606 ◽  
Author(s):  
X. Chen ◽  
S. Wang ◽  
Y.L. Yang ◽  
L. Smith ◽  
N.J. Wu ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Initial Pressure ◽  
Transient Behavior ◽  
Epitaxial Thin Films ◽  
Exchange Coefficient ◽  
Surface Exchange ◽  
Surface Exchange Coefficient ◽  
Pressure Changes ◽  
Oxygen Surface Exchange

AbstractLa0.5Sr0.5CoO3−δ (LSCO) can be used as a cathode material for low temperature solid oxide fuel cell applications. LSCO epitaxial thin films have been deposited on LaAlO3 substrates by pulsed laser deposition (PLD). The transient behavior of the thin film conductivity with the pressure changes was recorded as a function of temperature and partial oxygen pressure. The surface exchange coefficient k of the LSCO thin film was obtained from analysis of the electrical conductivity relaxation data. The measured surface exchange coefficient increases with temperature and with final pressure but is not sensitive to the initial pressure. After prolonged annealing at 900°C, the k value was found to have greatly increased. The mechanism of the dependence of the measured k on pressure is discussed.

scholarly journals Back-exchange: a novel approach to quantifying oxygen diffusion and surface exchange in ambient atmospheres

2017 ◽  
Vol 19 (19) ◽  
pp. 12199-12205 ◽  
Author(s):  
Samuel J. Cooper ◽  
Mathew Niania ◽  
Franca Hoffmann ◽  
John A. Kilner
Keyword(s):  
Isotopic Exchange ◽  
Ambient Air ◽  
Exchange Coefficient ◽  
Effective Surface ◽  
Surface Exchange ◽  
Electronic Conductor ◽  
Novel Approach ◽  
Mixed Ionic Electronic Conductor ◽  
Back Exchange ◽  
Surface Exchange Coefficient

A novel two-step Isotopic Exchange (IE) technique has been developed to investigate the influence of oxygen containing components of ambient air (such as H2O and CO2) on the effective surface exchange coefficient (k*) of a common mixed ionic electronic conductor material.

Oxygen diffusion and surface exchange in the mixed conducting oxides SrTi1−yFeyO3−δ

2016 ◽  
Vol 18 (42) ◽  
pp. 29495-29505 ◽  
Author(s):  
Veronika Metlenko ◽  
WooChul Jung ◽  
Sean R. Bishop ◽  
Harry L. Tuller ◽  
Roger A. De Souza
Keyword(s):  
Oxygen Diffusion ◽  
Oxygen Exchange ◽  
Exchange Coefficient ◽  
Surface Exchange ◽  
Conducting Oxides ◽  
Single Mechanism ◽  
Surface Exchange Coefficient

Variation of the surface exchange coefficient with Fe concentration suggests single mechanism of oxygen exchange for e−-poor and e−-rich SrTi1−yFeyO3−δ oxides.

scholarly journals Oxygen exchange at gas/oxide interfaces: how the apparent activation energy of the surface exchange coefficient depends on the kinetic regime

2016 ◽  
Vol 18 (32) ◽  
pp. 22031-22038 ◽  
Author(s):  
Peter Fielitz ◽  
Günter Borchardt
Keyword(s):  
Activation Energy ◽  
Apparent Activation Energy ◽  
Oxygen Exchange ◽  
Oxide Surfaces ◽  
Kinetic Regime ◽  
Exchange Coefficient ◽  
Surface Exchange ◽  
Oxide Interfaces ◽  
Surface Exchange Coefficient ◽  
Apparent Activation Energies

The model explains the range of apparent activation energies measured in different kinetic regimes of oxygen exchange at oxide surfaces.

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