Untangling surface oxygen exchange effects in YBa2Cu3O6+x thin films by electrical conductivity relaxation

The kinetics of oxygen incorporation and excorporation in YBCO epitaxial thin films was investigated by electrical conductivity relaxation measurements showing that the oxygenation kinetics of YBCO films is limited by the surface exchange process of oxygen molecules prior to bulk diffusion into the films.

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Electrical Conductivity Relaxation Study of Solid Oxide Fuel Cell Cathodes using Epitaxial (001)-Oriented Strontium-Doped Lanthanum Manganite Thin Films

MRS Proceedings ◽

10.1557/proc-1255-m02-02 ◽

2010 ◽

Vol 1255 ◽

Cited By ~ 2

Author(s):

Lu Yan ◽

Balasubramaniam Kavaipatti ◽

Shanling Wang ◽

Hui Du ◽

Paul Salvador

Keyword(s):

Thin Films ◽

Electrical Conductivity ◽

Elevated Temperatures ◽

Reduction Process ◽

Lanthanum Manganite ◽

Conductivity Relaxation ◽

Surface Exchange ◽

Electrical Conductivity Relaxation ◽

Crystal Films ◽

Surface Exchange Coefficient

AbstractEpitaxial single-crystal films of La0.7Sr0.3MnO3 (100) having smooth surface morphology were deposited on SrTiO3 (100) substrates by pulsed laser deposition (PLD). Electrical conductivity relaxation (ECR) measurements were carried out at elevated temperatures over a range of absolute oxygen pressures to determine the oxygen surface exchange coefficient. Steady-state conductivity data of the thin films show good agreement with the bulk material's properties. The values of the oxygen exchange coefficients (Kchem) are found to be similar for both oxidation and reduction process between 50 and 500 mTorr O2. The activation energy (Ea) of Kchem is 1.00±0.27 eV at temperatures above 600 °C and Kchem (T=612°C)≈1.2×10-6 cm/s.

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Simultaneous Optical Transmission Relaxation and Electrical Conductivity Relaxation Measurements of Oxygen Surface Exchange Kinetics during Crystallization

ECS Meeting Abstracts ◽

10.1149/ma2019-02/40/1887 ◽

2019 ◽

Keyword(s):

Electrical Conductivity ◽

Optical Transmission ◽

Conductivity Relaxation ◽

Surface Exchange ◽

Electrical Conductivity Relaxation ◽

Relaxation Measurements ◽

Exchange Kinetics ◽

Oxygen Surface Exchange ◽

Oxygen Surface

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Influence of Heterointerfaces on the Kinetics of Oxygen Surface Exchange on Epitaxial La1.85Sr0.15CuO4 Thin Films

Applied Sciences ◽

10.3390/app11093778 ◽

2021 ◽

Vol 11 (9) ◽

pp. 3778

Author(s):

Gene Yang ◽

So-Yeun Kim ◽

Changhee Sohn ◽

Jong K. Keum ◽

Dongkyu Lee

Keyword(s):

Thin Films ◽

Oxygen Vacancies ◽

Elevated Temperatures ◽

Surface Exchange ◽

Electrical Conductivity Relaxation ◽

Exchange Kinetics ◽

Relaxation Curves ◽

Kinetics Of ◽

Oxygen Surface Exchange ◽

Oxygen Surface

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.

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