Perovskite structure chromites are one of the most important family of functional materials, especially useful as interconnect materials in solid oxide fuel cells (SOFCs). In this paper, the relationship of the structure, valence states of Cr, and electrical conductivity of La0.8Ca0.2CrO3 and La0.7Ca0.2Sr0.1CrO3 were studied. The samples were synthesized by solid state reaction under air or nitrogen condition, respectively. It is found that the relationship of AC conductivity with frequency is in consistent with Jonscher power law when the frequency is between 2 x 10(2)-2 x 10(6) Hz. The electrical resistivity is in line with temperature change, which means that the conduction mechanism is small polaron theory and meets Arrhenius formula. Binding energy of the Cr-2p in the compounds synthesized in air corresponded to 576.4 eV, 577.6 eV and 579.7 eV, which means the valence states of Cr are +3, +5 and +6. But for the compounds synthesized in N-2 atmosphere the valence states of Cr are +3 and +6. (C) 2016 Elsevier B.V. All rights reserved.
[1]Jilin Univ, Clin Hosp 2, Changchun 130041, Peoples R China.
[2]Jilin Univ, Clin Hosp 1, Changchun 130021, Peoples R China.
[3]Jilin Univ, Coll Chem, State Key Lab Inorgan Synth & Preparat Chem, Changchun 130012, Peoples R China.
(8.0+极速模式)