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Indexed by:期刊论文

Date of Publication:2014-07-28

Journal:JOURNAL OF MATERIALS CHEMISTRY C

Included Journals:SCIE、EI、Scopus

Volume:2

Issue:28

Page Number:5660-5666

ISSN No.:2050-7526

Abstract:The redox reactions of highly epitaxial LaBaCo2O5+delta (LBCO) thin films exposed to the switching flow of reducing (H-2) and oxidizing (O-2) gases were examined at various temperatures between 260 and 700 degrees C. Their electrical resistance was measured using a precise ac bridge measurement system. The as-grown LBCO films have very good electrical conductivity at low and medium temperatures between 400 and 700 degrees C, and are extremely sensitive to reducing and oxidizing environments with superfast redox dynamics. The LBCO thin films show more complex redox reactions at low temperatures (300-350 degrees C), suggesting the occurrence of conducting-to-insulating-to-conducting transitions during the redox reactions. In particular, the insulating-to-conducting transition under an oxidation process is superfast, with the largest resistance change of up to 3 x 10(7) Omega s(-1), occurring even at a low temperature of 300 degrees C. The extremely short response time, the giant resistance change, and the excellent chemical stability in a broad temperature range from 260 to 700 degrees C suggests that the highly epitaxial LBCO thin-films can be excellent candidates for low-temperature solid oxide fuel cells, chemical sensors, and catalyst applications.