Preparation and Properties of (YCa)(TiMn)O_3-d Ceramics Interconnect of Solid Oxide Fuel Cells

(YCa)(TiMn)O_3-d ceramics prepared using a reaction-sintering process were investigated. Without any calcination involved, the mixture of raw materials was pressed and sintered directly. Y₂Ti₂O₇ instead of YTiO₃ formed when a mixture of Y₂O₃ and TiO₂ with Y/Ti ratio 1/1 were sintered in air. Y₂Ti₂O₇, YTiO_2.085 and some unknown phases were detected in Y_0.6Ca_0.4Ti_0.6Mn_0.4O_3-d. Monophasic Y_0.6Ca_0.4Ti_0.4Mn_0.6O_3-d ceramics were obtained after 1400-1500 °C sintering. Dense Y_0.6Ca_0.4Ti_0.4Mn_0.6O_3-d with a density 4.69 g/cm³ was observed after 1500 °C/4 h sintering. Log σ for Y_0.6Ca_0.4Ti_0.6Mn_0.4O_3-d increased from -3.73 Scm^-1 at 350 °C to -2.14 Scm^-1 at 700 °C. Log σ for Y_0.6Ca_0.4Ti_0.4Mn_0.6O_3-d increased from -2.1 Scm^-1 at 350 °C to -1.36 Scm^-1 at 700 °C. Increasing Mn content decreased activation energy E_a and increased electrical conductivity. Reaction-sintering process is proved to be a simple and effective method to obtain (YCa)(TiMn)O_3-d ceramics for interconnects in solid oxide fuel cells.