Bi_(1-x)La_xFeO_3 ceramics with x=0, 0.1, 0.2, and 0.3 have been synthesized by solid state reaction, starting from metal oxides. A series of structure transformations is found to depend upon the doping level. Below 10 percent La doping, Bi_(1-x)La_xFeO_3 maintains the rhombohedral structure of BiFeO_3. However, for Bi_(0.8)La_(0.2)FeO_3 and Bi_(0.7)La_(0.3)FeO_3, the structures change to the orthorhombic and tetragonal, respectively. La doping significantly reduces electric leakage and leads to successful observation of electrical polarization hysteresis loops. Doping with La also enhances the ferromagnetic moment, due to the broken cycloid spin structure caused by the changes in the crystalline structure.
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