The conductivity of the entire solid solution La1-xSrxFeO3-δ, where x = 0.2, 0.4, 0.5, 0.7 or 0.9, in the O partial pressure range 10-19 to 0.5atm and at between 750C and 950C was reported. The partial contributions from different charge carriers and the energetic parameters governing transport of charged species reveal that the lanthanum–strontium ferrites could be characterized as mixed, ion–electron conductors in the low O pressure/high O deficiency limit. The partial contributions to conductivity from O ions, electrons and holes increase with Sr content and attain maximal values at x = 0.5. Further increase in doping resulted in development of O vacancy ordering phenomena and deterioration of conducting properties.

Electron/Hole and Ion Transport in La1-xSrxFeO3-δ. M.V.Patrakeev, J.A.Bahteeva, E.B.Mitberg, I.A.Leonidov, V.L.Kozhevnikov, K.R.Poeppelmeier: Journal of Solid State Chemistry, 2003, 172[1], 219-31