Journal Article
ECS Transactions, vol. 28, iss. 23, pp. 137-146, 2010
Authors
Lincoln Miara, Kyung Joong Yoon, Stephen G. Topping, Lax Saraf, Uday Pal, Srikanth Gopalan
Abstract
Patterned cathodes of calcium-doped lanthanum manganite (LCM) were fabricated on polycrystalline yttria-stabilized zirconia (YSZ) substrates by RF magnetron sputtering and photolithographic techniques. Samples were generated with a constant electrode/electrolyte contact area but different three phase boundary (TPB) lengths (lTPB's). Electrochemical impedance spectroscopy (EIS) was performed in the oxygen partial pressure (pO2) and temperature range of 10-3 atm to 1.00 atm and 600-800{degree sign}C respectively. The area specific polarization resistance, Rp, was found to scale linearly with the inverse of lTPB, suggesting that the TPB is the active region for oxygen reduction. The resistivity decreased with increased temperature and pO2 and showed an activation energy of 1.17+/-0.03 eV.
