Multiferroic bismuth manganite prepared by mechanochemical synthesis

Multiferroic bismuth manganite (BiMnO3) is known as a material that exhibits both ferromagnetic and ferroelectric properties making it interesting for various technological applications. Unfortunately, preparation of BiMnO3 is not possible by a conventional solid-state reaction and it can form only from mixture of oxides at high pressures (>40 kbar).In this work single-phased BiMnO3 was prepared for the first time by mechanochemical synthesis in a planetary ball mill. A mixture of Bi2O3 and Mn2O3 was intensively milled in air atmosphere, using stainless steel vials and balls. According to analysis of XPRD results BiMnO3 obtained after milling for 240 min has a tetragonal structure with lattice parameters a = 3.9230 Å, c = 3.920 Å and a crystallite size of 16.8 nm. The cumulative energy introduced into the system during milling for 240 min was 401 kJ/g. It was found that the obtained powders were agglomerated. Corresponding agglomeration factors were calculated from the results of BET and particle size distribution analysis.