High‐Temperature Electrical Conductivity of LaCr1−xCoxO3 Ceramics. Issue 3 (13th December 2015)

• Record Type: Journal Article
• Authors: Bonet, Alexander; to Baben, Moritz; Travitzky, Nahum; Greil, Peter
• Editors: Feteira, A.
• Is Part Of: Journal of the American Ceramic Society. Volume 99:Issue 3(2016)
• Page Start: 917
• Page End: 921
• Publication Date: 2015-12-13
• Subjects: Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.14038
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract : LaCr1− x Co x O3 solid‐solution ceramics ( x = 0.0–0.3) were prepared by pressureless sintering of a submicrometer powder. The powder was synthesized by a modified glycine nitrate process at 800°C. The electrical conductivity of the material sintered at 1600°C was measured by AC four‐wire method from room temperature to 1200°C. While undoped ( x = 0) LaCrO3 revealed semiconductivity dominated by thermally activated mobility of small polarons over a vast temperature range, substitution of Co for Cr gave rise for a pronounced enhancement of conductivity at temperatures >200°C. XPS analysis showed that the concentration of Cr 4+ on the Cr‐site and Co 2+ at the Co‐site increased with Co substitution suggesting a thermally activated redox reaction Cr 3+ + Co 3+ →Cr 4+ + Co 2+ to create additional charge carriers. Thus, Co doping offers a high potential for designing the electrical conductivity making LaCr1− x Co x O3 an interesting resistivity material for high temperature applications.