Hydrothermal synthesis and the structural, morphologic and magnetic characteristics of Mn doped bismuth ferrite crystallites

Well-crystallized bismuth ferrite (BiFeO₃) and Mn-doped BiFeO₃ particles (BiFe_1−xMn_xO₃: x = 0, 0.02, 0.06, 0.10, 0.15, 0.20) were successfully prepared using a hydrothermal method with the mineralizer of KOH. The phase structure, morphology, optical and magnetic properties of the as-prepared samples were investigated by X-ray diffraction (XRD), scanning electron microscope, Raman spectroscopy, and physical properties measurements system, respectively. Phase purity of all samples was confirmed from XRD measurements. Spherical aggregated structure of all samples was observed at low magnification and the spherical particles consist of large amounts of small particles. The size of these small particles decrease with the increasing Mn content. It was found that with the increasing of Mn content, within the range of x = 0.06–0.20, a structural phase transition from rhombohedral to orthorhombic system occurs. Maximum magnetization at 20 K Oe was obtained in BiFe_0.9Mn_0.1O₃ and weak ferromagnetic properties were observed as the Mn concentration exceeds 0.1.