Synthesis and characterization of submicron single-crystalline Bi2Fe4O9 cubes

Single-crystalline, submicron-sized Bi2Fe4O9 cubes of reproducible shape have been successfully prepared using a facile, large-scale solid-state reaction employing a molten salt technique in the presence of a nonionic surfactant. The role of surfactant as well as alterations in the molar ratio of Bi3+ to Fe3+ precursors have been examined under otherwise identical reaction conditions and correlated with the predictive formation of different shapes of Bi2Fe4O9 products. Extensive structural characterization of as-prepared samples has been performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), energy-dispersive X-ray spectroscopy (EDS), selected area electron diffraction (SAED), Mossbauer spectroscopy, and X-ray diffraction (XRD). Magnetic measurements were obtained using a superconducting quantum interference device (SQUID).