A novel one-pot metathesis route for the synthesis of double perovskites, Ba3MM′2O9(M = Mg, Ni, Zn; M′ = Nb, Ta) with 1 : 2 ordering of M and M′ atoms

Abstract
Solid state reaction of Li2CO3, MC2O4·2H2O (M = Mg, Ni, Zn), M′2O5 (M′ = Nb, Ta) and BaCl2 in stoichiometric quantities at 900–1100 °C in air provides a convenient one-pot synthesis route for 1 : 2 B-site ordered double perovskite oxides, Ba3MM′2O9, that find application in microwave telecommunications.