In this study synthesis and sintering properties of lanthanum chromite doped by Sr, Ni and Ca including two main compositions as La 1-x Sr x Cr 1-y Ni y O 3 (0 x 0.3 and 0 y 0.2) and La 1-x-y Sr x Ca y CrO 3 (0 x 0.3 and 0 y 0.3) were investigated. Ultrafine powder of doped lanthanum chromites with average particle size of 150 nm, was successfully synthesized by the simple process of glycine nitrate. The samples were characterized by thermal analysis (DTA-TG), X-ray diffraction, and nitrogen adsorption–desorption, scanning and transmission electron microscopy. The synthesized ultrafine powders had perovskite type crystal structure and some SrCrO 4 or CaCrO 4 phases were detected in high content doping element. The samples were cold isostatically pressed at 200 MPa, and then sintered in air at 1400 and 1500 ?C for several time periods (1–10 h). Relative density measurements were conducted by Archimedes method. The maximum relative density for La 1-x-y Sr x Ca y CrO 3 samples obtained after sintering in air at 1400 ?C for 3 h was 98.2% of the theoretical density and the average grain size of the sintered pellets was about 2 µm. In addition, the effects of composition on phase transition behavior and electrical properties were studied. Base on the sintering mechanism, a simple method was developed to fabricate dense doped LaCrO 3 interconnect membrane on anode substrate for solid oxide fuel cell (SOFC) applications by co-sintering. As conventional lanthanum chromite interconnect is difficult to be co-sintered with green anode, a simple and cost effective screen printing/co-sintering process was employed, and dense La 1-x-y Sr x Ca y CrO 3-? interconnect membrane was successfully prepared on the anode support of NiO-YSZ. In this method a base layer of doped lanthanum chromite (La 1-x Sr x CrO 3-? ) was applied on NiO-YSZ substrate and a top layer of CaCrO 4 was then coated and co-sintered to melt the top layer. By means of this method, not only CaCrO 4 melts and fills the open pores in the base layer, but it also dissolves in base layer forming La 1-x-y Sr x Ca y CrO 3-? as a single layer. In addition, synthesis and characterization of doped lanthanum chromite and CaCrO 4 by glycine nitrate method, sintering characteristics, microstructure and electrical conductivity of interconnect were investigated. Keywords: Solid Oxide Fuel Cell, Interconnect material, Co-sintering, Lanthanum chromite, Electrical properties.
