Mechanochemical synthesis of LaMnO₃ from La₂O₃ and Mn₂O₃ powders

Perovskite-type lanthanum manganite (LaMnO₃) powder was synthesized by room temperature milling of La₂O₃ and Mn₂O₃ powders using a planetary ball mill. The synthesis reaction proceeds with increase in milling time and is finished by about 180 min. The reaction process was quantitatively evaluated by measuring the percentage of free (unreacted) La₂O₃ in the milled samples. The product powder (LaMnO₃) has large specific surface area of about 10 m²/g, which is comparable to the data obtained by the complex chemical synthesis methods. The mechanochemical process can also be applied to synthesis of manganese complex oxides with other rare earth elements such as Pr, Nd and Sm.