Chemical Compatibility between Strontium‐Doped Lanthanum Manganite and Yttria‐Stabilized Zirconia

Abstract

Equimolar powder mixtures and multilayer pellets of single‐phase Sr‐doped lanthanum manganite perovskite materials La y‐x Sr x MnO 3 with La content y = 1 and 0.95 and Sr content 0 ≤ x ≤ 0.5 were annealed in air with 8 mol% Y 2 O 3 ‐ZrO 2 at 1470 K, up to 400 h and at 1670 K. up to 200 h. X‐ray diffraction and electron probe microanalysis confirmed the formation of La 2 Zr 2 O 7 or SrZrO 3 depending on the composition of the perovskites. No reaction products could be detected for La 0.95‐x Sr x MnO 3 with 0.2 ≤ x ≤ 0.4 after annealing for 400 h at 1470 K, and for the perovskite La 0.65 Sr 0.3 MnO 3 even after annealing for 200 h at 1670 K. The results demonstrate the improved chemical compatibility of La‐deficient perovskites against reaction with zirconia and can provide a basis for the selection of a sufficiently chemically stable material for the air electrode of solid oxide fuel cells.