Y_(0.8)Sr_(0.2)CrO_(3-δ)超细粉体制备及其低温致密化烧结

Synthesis and Low-temperature Sintering of Y_(0.8)Sr_(0.2)CrO_(3-δ) Ultrafine Powder

铬酸钇与铬酸镧基固体氧化物燃料电池陶瓷连接材料相比具有更高的化学稳定性,但是却难以在空气中致密化烧结。本文利用微波辅助的溶胶-凝胶工艺制备Y0.8Sr0.2CrO3-δ超细粉体(粒径30～50nm),并掺入少量的CaF2作为烧结助剂,在1400℃空气气氛下获得了高致密度的烧结体。当CaF2掺入量达到9%(质量分数)时,样品致密度达到97.6%,仍然遵从小极子导电机理,850℃时电导率为2.7Scm-1,完全能够满足中温燃料电池连接材料的使用要求。

Comparing with LaCrO_3-based interconnect materials of solid oxide fuel cells（SOFCs）,YCrO_3 has a higher chemical stability under SOFCs fabrication conditions.However,there are few reports on the dense samples sintered at the cell co-firing temperature in air.In this work,the ultrafine precursor powder of Y_（0.8）Sr_（0.2）CrO_（3-δ） was prepared by microwave aided solgel process,and then sintered in air at 1400℃ for 4h using a small amount of CaF_2 as sintering aid.Results indicate the sintered specimens have a high relative density of 97.6% and still obey the small polaronic conduction mechanism when 9wt% CaF_2 was added.The electrical conductivity of the dense sintered samples reaches to 2.7Scm～（-1） at 850℃ in air,indicating this material is suitable for IT-SOFCs as an interconnect material.