부산대학교 도서관

La0.9Sr0.1CrO3-δ has been selected as base material for fuel cell interconnect. The effects of Ni substitution on the B site of lanthanum strontium chromite (La0.9Sr0.1CrO3) have been investigated on phase, microstructure and electrical conductivity. All compositions were synthesized by citrate gel combustion method. The suitable calcination temperature of these compositions to obtain a perovskite phase was 1100°C with a soaking period for 4 h. The sample bars were formed by cold isostatic press and sintered at 1,400°C for 5 h in air. The phase, microstructure, thermal expansion coefficient (TEC) and electrical conductivity were determined by XRD, SEM, Dilatometer and dc four-probe as a function of temperature. For the compositions with x ≤ 0.5, the results show a single phase after sintering and the conductivity of Ni-doped composition increases as Ni content increases. The maximum conductivity of 72.76 S cm-1 at 800°C in air was obtained from La0.9Sr0.1Cr0.5Ni0.5O3-δ and its activation energy in the range of 100-800°C was 0.15 eV. The thermal expansion coefficient in a temperature range of 200 - 800°C for this composition was 12.5 × 10-6 K-1. [ABSTRACT FROM AUTHOR]