A new intermediate temperature mixed conducting material was fabricated which was based upon acceptor doping of this ferrite. Acceptor doping to levels of 5mol%, with Ca or Sr, was found to increase the maximum operating temperature more than 100C and eliminate secondary phase formation. Mixed ionic and electronic conductivity was confirmed by measuring the O permeation properties of doped ceramics which exhibited fluxes of the order of 0.018µmol/cm2s at 800C over an O partial pressure range of 0.21atm (air) to 10-6atm(He). Ceramic membranes exhibited an increase in O flux with decreasing sample thickness; thus indicating good surface catalysis properties of the system.

Acceptor Doped BiFeO3 Ceramics - a New Material for Oxygen Permeation Membranes. K.Brinkman, T.Iijima, H.Takamura: Japanese Journal of Applied Physics, 2007, 46[4], L93-6