Chemistry of Interactions in the La2O3—MO (MCO3)—Mn2O3, M: Ca, Sr, Ba, Cd Systems.

Abstract The sequence of phase transitions in the system La 2 O 3 -MO(MCO 3 )Mn 2 O 3 , (M=Ca, Sr, Ba, Cd) and the span range of La 1−x M x MnO 3±δ solid solutions formed were studied. It is demonstrated that interaction begins at 650°C due to formation of divalent metal manganites. Just simultaneously as a result of oxidation-reduction processes and structural transformations the synthesis of small quantities of solid solutions takes place, which is kinetically favoured in the case of smaller divalent metal cations. The chemical transformation finishes at 1200°C. The values of x at all systems are near 0,35. The absence of CdMnO 3 composition in the system CdO-MnO is proved.