CHEMISTRY OF INTERACTIONS IN THE LA2O3-MO(MCO3)-MN2O3, M=CA, SR, BA, CD SYSTEMS

The sequence of phase transitions in the system La2O3-MO(MCO3)Mn2O3, ( M=Ca, Sr, Ba, Cd) and the span range of La1-xMxMnO3+delta solid soluti ons formed were studied. It is demonstrated that interaction begins at 650 degrees C due to formation of divalent metal manganites. Just sim ultaneously as a result of oxidation-reduction processes and structura l transformations the synthesis of small quantities of solid solutions takes place, which is kinetically favoured in the case of smaller div alent metal cations. The chemical transformation finishes at 1200 degr ees C. The values of x at all systems are near 0,35. The absence of Cd MnO3 composition in the system CdO-MnO is proved.