Electronic properties and oxygen nonstoichiometry of mixed-conducting oxide La1-xSrxCoO3-δ thin films at high temperature

D. Hemmi, K. Iwamoto, N. Hirai, M. Sase, A. Unemoto, T. Nakamura, F. Horikiri, Y. Mori, K. Sato, K. Yashiro, T. Kawada, J. Mizusaki

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Citations (Scopus)

Abstract

Thin films of the perovskite-type oxide La1-xSr xCoO3-δ were deposited onto Ce0.9Gd 0.1O1.95, SiO2 and single crystal MgO (100) substrates surface by a pulsed laser deposition (PLD) using a XeC1 excimer laser to study the difference of the electronic properties and nonstoichiometry. It was shown that the oxygen nonstoichiometry of thin film is smaller than that of bulk for Lai. xSrxCoO3-δ. The conductivity of the films were measured by a DC four probe method in 10 -4-1 bar O2 gas at temperatures of 25-800°C. The activation energy of the conductivity for thin films strongly depends on substrates due to the mismatch of the thermal expansion coefficient between the thin film and the substrate. Although the temperature coefficient of conductivity of La1. xSrxCoO 3-δ bulk was negative for x>0.4 and was positive for 0<x<0.3, that of thin film was positive irrespective of x. At the condition with the Co mean valence of 3.0 for x=0.4, 0.5, the conductivity shows large values for bulk, on the other hand, the conductivity is close to 0 for thin film. These facts suggest the electron hole in bulk is delocalized and metal like, while that in thin film is localized on cobalt ion.

Original languageEnglish
Title of host publicationECS Transactions - Solid State Ionic Devices 6 - Nanoionics - 214th ECS Meeting
Pages311-316
Number of pages6
Edition51
DOIs
Publication statusPublished - 2008 Dec 1
EventSolid State Ionic Devices 6 - Nanoionics - 214th ECS Meeting - Honolulu, HI, United States
Duration: 2008 Oct 122008 Oct 17

Publication series

NameECS Transactions
Number51
Volume16
ISSN (Print)1938-5862
ISSN (Electronic)1938-6737

Other

OtherSolid State Ionic Devices 6 - Nanoionics - 214th ECS Meeting
CountryUnited States
CityHonolulu, HI
Period08/10/1208/10/17

ASJC Scopus subject areas

  • Engineering(all)

Fingerprint Dive into the research topics of 'Electronic properties and oxygen nonstoichiometry of mixed-conducting oxide La<sub>1-x</sub>Sr<sub>x</sub>CoO<sub>3-δ</sub> thin films at high temperature'. Together they form a unique fingerprint.

Cite this