Chemical stability of Ca or Sr doped lanthanum chromites under high temperature reduced atmosphere
Zhou Hua Bing; Taira Hiroaki; Takagi Hiroshi; Tomono Kunisaburo
Abstract:Lanthanum chromites ((La, A)(Cr, M)O3; A =Ca, Sr, M =Co, Ni, Cu, Zn) were synthesized and characterized from their density, thermal expansion coefficient and chemical stability. Cobalt doped lanthanum calcium chromites with La-site/Cr-site ratio greater than 1 were densely sintered at 1400 degree, and it is possible to adjust the thermal expansion coefficient to that of YSZ by controlling the amount of dopants. Lanthanum strontium chromites with La-site/Cr-site ratio =1 were not densely sintered at lower temperature than Ca-doped, but kept enough strength after reduction treatment, difference of strength change after the reduction treatment between Sr-doped and Ca-doped ones is related to the difference in lattice expansion after the treatment. Key Words:lanthanum chromite, SOFC, interconnect, sinterability, thermal expansion coefficient, stability under reduced atmosphere