scholarly journals Oxygen surface exchange kinetics and stability of (La,Sr)2CoO4±δ/La1−xSrxMO3−δ (M = Co and Fe) hetero-interfaces at intermediate temperatures

2015 ◽  
Vol 3 (5) ◽  
pp. 2144-2157 ◽  
Author(s):  
Dongkyu Lee ◽  
Yueh-Lin Lee ◽  
Wesley T. Hong ◽  
Michael D. Biegalski ◽  
Dane Morgan ◽  
...  

The effect of (La0.5Sr0.5)CoO4±δ decoration on the time-dependent surface exchange coefficient (kq) of epitaxial La0.8Sr0.2CoO3−δ and La0.6Sr0.4Co0.2Fe0.8O3−δ thin films.

2021 ◽  
Vol 11 (9) ◽  
pp. 3778
Author(s):  
Gene Yang ◽  
So-Yeun Kim ◽  
Changhee Sohn ◽  
Jong K. Keum ◽  
Dongkyu Lee

Considerable attention has been directed to understanding the influence of heterointerfaces between Ruddlesden–Popper (RP) phases and ABO3 perovskites on the kinetics of oxygen electrocatalysis at elevated temperatures. Here, we report the effect of heterointerfaces on the oxygen surface exchange kinetics by employing heteroepitaxial oxide thin films formed by decorating LaNiO3 (LNO) on La1.85Sr0.15CuO4 (LSCO) thin films. Regardless of LNO decoration, tensile in-plane strain on LSCO films does not change. The oxygen surface exchange coefficients (kchem) of LSCO films extracted from electrical conductivity relaxation curves significantly increase with partial decorations of LNO, whereas full LNO coverage leads to the reduction in the kchem of LSCO films. The activation energy for oxygen exchange in LSCO films significantly decreases with partial LNO decorations in contrast with the full coverage of LNO. Optical spectroscopy reveals the increased oxygen vacancies in the partially covered LSCO films relative to the undecorated LSCO film. We attribute the enhanced oxygen surface exchange kinetics of LSCO to the increased oxygen vacancies by creating the heterointerface between LSCO and LNO.


1999 ◽  
Vol 606 ◽  
Author(s):  
X. Chen ◽  
S. Wang ◽  
Y.L. Yang ◽  
L. Smith ◽  
N.J. Wu ◽  
...  

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.


2014 ◽  
Vol 2 (18) ◽  
pp. 6480-6487 ◽  
Author(s):  
Dongkyu Lee ◽  
Yueh-Lin Lee ◽  
Alexis Grimaud ◽  
Wesley T. Hong ◽  
Michael D. Biegalski ◽  
...  

Strong Sr dependence of the oxygen surface exchange kinetics for the La2−xSrxNiO4±δ (LSNO) thin films.


2015 ◽  
Vol 3 (45) ◽  
pp. 22759-22769 ◽  
Author(s):  
Ghislain M. Rupp ◽  
Helena Téllez ◽  
John Druce ◽  
Andreas Limbeck ◽  
Tatsumi Ishihara ◽  
...  

Correlation between the surface chemistry of LSC thin films analyzed by LEIS and ICP-MS and the oxygen exchange kinetics.


2019 ◽  
Vol 11 (35) ◽  
pp. 31786-31792 ◽  
Author(s):  
Doyeub Kim ◽  
Jin Wan Park ◽  
Byung-Hyun Yun ◽  
Jeong Hwa Park ◽  
Kang Taek Lee

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