Dimensional stability and defect chemistry of doped lanthanum chromites

Acceptor doped lanthanum chromites are potential interconnect materials to be used in high temperature Solid Oxide Fuel Cells (SOFC). However, instability of these materials when exposed to low oxygen partial pressure causes a volume expansion that can be detrimental to the SOFC performance. The stability of L0.8Sr0.2Cr0.97V0.03O3 determined as function of pO(2) and temperature by isothermal thermogravimetry and dilatometry. The experimental data are analysed using a simple model fbr the defect chemistry. The relation between expansion behaviour and change in defect chemistry is discussed using a simple structural model.