Synthesis of Various LaMO 3 Perovskites in Molten Carbonates

Lanthanum‐containing perovskites, LaMO 3 (M=Al, Sc, Cr, Mn, Fe, Co, Ni, Ga, and In), have been synthesized in molten carbonates from a mixture of lanthanum carbonate and an M‐containing oxide or an acetate, or from a co‐precipitation mixture of metal (M) and lanthanum. Metal aluminum, chromium, and iron, immersed in a mixture of molten (Li 0.52 Na 0.48 ) 2 CO 3 and lanthanum carbonate at 923 K, were covered, respectively, with LaAlO 3 , LaCrO 3 , and LaFeO 3 . Ceramic and single‐crystal α‐Al 2 O 3 , immersed in molten (Li 0.52 Na 0.48 ) 2 CO 3 mixed with lanthanum carbonate, were also covered with LaAlO 3 . In situ X‐ray diffractometry revealed that La 2 O 2 CO 3 reacted with α‐LiAlO 2 to yield LaAlO 3 ; the reaction proceeded faster under N 2 than under a CO 2 atmosphere.