Patent ID: 8318119

Claim:
A method comprising: dissolving precursor constituent metal salts, which comprise salts of Lanthanum and manganese, and an amount of citric acid into water to form an aqueous liquid medium, the precursor constituent metal salts providing dissolved constituent metal cations that react with citric acid to form citrate complexed mixed metal compounds, the amount of citric acid included in the aqueous liquid medium ranging from about 40 mol % to about 100 mol % in excess of that needed to stoichiometrically complex with the dissolved constituent metal cations; removing water from the aqueous liquid medium to concentrate the citrate complexed mixed metal compounds into an amorphous gel; converting the citrate complexed mixed metal compounds into perovskite oxide particles having a crystal structure represented by the general formula La 1-x A1 x MnO 3 , wherein A1 is a promoter metal cation and x ranges from about 0 to about 0.5.