Material for solid state sintered material.

A solid state sintered material is described that includes a mixed oxide of lanthanum, strontium, cobalt, iron and oxygen, and CaCOinclusions. The solid state sintered material can also include calcium oxide, which can form from thermal composition of calcium carbonate. The solid state sintered material can also include a pore-forming particulate material such as carbon black and/or a doped ceramic metal oxide ionic conductor such as Sm-doped ceria uniformly dispersed in the solid state sintered material. The solid state sintered material can be formed from a two-step process in which a portion of the CaCOis mixed with the mixed oxide materials and heated to form porous agglomerates, and the remaining CaCOis added during the formation of a sintering paste. The solid state sintered material described herein can be used as a cathode material (28) for a solid oxide fuel cell (20).