Solvothermal synthesis of nano-to-submicrometer sized BiFeO3 and Bi-Fe-oxides with various morphologies

We elaborate an ethanol-water mixture solvent mediated synthesis of Bi-Fe-oxides (including Bi2Fe4O9 and BiFeO3) having different morphological attributes. NaOH was used to make the solvent basic. We systematically unfold required conditions to obtain pure phase as well as structured multiferrous BiFeO3. The starting materials in each attempt were bismuth nitrate and ferric nitrate (1:1 molar ratio). The nano-and micrometer-sized BiFeO3 was obtained when the synthesis temperature and duration were around 200 degrees - 230 degrees C and three hours, respectively. This duration is very small compared to those reported earlier. It is observed that for higher amount of NaOH (4.0-10.0 gm), for same synthesis time and duration, the product is neither pure BiFeO3 nor Bi2Fe4O9, but a mixed phases of Bi-Fe oxides. Pure phase BiFeO3 was also obtained at 150 degrees C for a synthesis time of 12 hr which is three times shorter than those reported earlier. Similar experiment in ethylenedimene-water mixture solvent yielded mixed phases of Bi12.5Fe0.5O19.5 and Bi2Fe4O9.