PHYSICAL PROPERTIES OF La0.9Sr0.1Cr1-XNiXO3-δ (X = 0-0.6) SYNTHESIZED VIA CITRATE GEL COMBUSTION
Keywords:
Solid oxide fuel cell, LaCrO3, citrate gel, interconnectAbstract
La0.9Sr0.1CrO3-δ has been selected as base material for fuel cell interconnect. The effects of Nisubstitution on the B site of lanthanum strontium chromite (La0.9Sr0.1CrO3) have been investigatedon phase, microstructure and electrical conductivity. All compositions were synthesized by citrate gelcombustion method. The suitable calcination temperature of these compositions to obtain a perovskitephase was 1100°C with a soaking period for 4 h. The sample bars were formed by cold isostaticpress 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 afunction of temperature. For the compositions with x ≤ 0.5, the results show a single phase aftersintering and the conductivity of Ni-doped composition increases as Ni content increases. Themaximum conductivity of 72.76 S cm-1 at 800°C in air was obtained from La0.9Sr0.1Cr0.5Ni0.5O3-δ andits activation energy in the range of 100-800°C was 0.15 eV. The thermal expansion coefficient in atemperature range of 200 - 800°C for this composition was 12.5 × 10-6 K-1.
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