Powder samples of LaCoO3, LC, and La1-xBaxCoO3, with LBC, x = 0.0 to 1.0, were prepared by using the polymerized complex technique at relatively low temperatures. The complex solution was heated at 130C to produce a gel. Pyrolysis of the gel at 350C then yielded a powder precursor. Thermal analysis, X-ray diffraction and IR spectra indicated the formation of cubic material when the precursors were heated above 500C in air for 2h. Traces of the parent oxides appeared in samples prepared via solid-state reaction; even at sintering temperatures of 900C. The lattice vibrations, as a function of Ba addition, revealed structural changes with temperature or Ba content. The amounts of metal in the samples after annealing confirmed that the composition was LaCoO3 at 900C. The electrical conductivity of La1-xBaxCoO3 (formed at 900C for 2h), as a function of x, was measured at those temperatures where the conductivity increased with temperature. The substitution of La for Ba enhanced the oxide-ion conductivity for 0 = 0 to 0.5. It decreased with further increases in x.

Synthesis, X-Ray, Infrared Spectra and Electrical Conductivity of La/Ba–CoO3 Systems. M.S.Khalil: Materials Science and Engineering A, 2003, 352[1-2], 64-70