On the Possibility of Synthesizing Bimno₃ at Ambient Pressure Using Low-Temperature Methods

BiMnO₃ exhibit multiferroic properties, which attract much attention due to numerous potential applications. The most well-investigated and traditional techniques for synthesizing this material include high-pressure and high-temperature treatment. In this way, soft chemistry synthesis of BiMnO₃ is desirable. Even though the formation of BiMnO₃ at ambient pressure is not possible according to the phase diagram, many scientific groups are focused on solving this problem. In the present work, we have tested four soft chemistry routes, namely hydrothermal route, two gel methods, and coprecipitation for synthesizing BiMnO₃ from Cl^– and NO₃ ^–-containing solutions at ambient pressure in the temperature range of 200–800°C, and none resulted in the formation of BiMnO₃. The experiment showed that under hydrothermal conditions manganese and bismuth oxides remain unreacted, and the other tested methods produce Bi₂Mn₄O₁₀ and Bi₁₂MnO₂₀ instead. The formation of Bi₂Mn₄O₁₀ and Bi₁₂MnO₂₀ from Cl^–-containing solutions occurs with BiOCl being formed as an intermediate phase.