| Abstract: | Preparation of Ceramic Powders. IX. NiMn2O4 and ZnMn2O4 Formation by Decomposition of Ni(H2O)6] (MnO4)2 and Zn(H2O)6] (MnO4)2 Improved preparation of Ba(MnO4)2 from BaMnO4 is reported. Thermal or hydrothermal decomposition of Ni(H2O)6] (MnO4)2 yields intermediately an amorphous manganate(IV) which forms crystalline NiMnO3 and α-Mn2O3 in the range T > 400°C. NiMn2O4 is formed above 730°C in accordance with the phase diagram. On the other hand, ZnMn2O4 is already at 300°C obtained from Zn(H2O)6](MnO4)2 at hydrothermal conditions. |
