La-doped BiFeO₃：Synthesis and multiferroic property study

A new sol-foam-gel method was developed to fabricate La-doped BiFeO₃ multiferroic materials. It was demonstrated that a gradual increase in the content of La-doped into BiFeO₃ results in its structure changing from rhombohedral to orthorhombic. A study of other property changes indicates that La-doping in BiFeO₃ enhances its ferromagnetism and ferroelectricity. A temperature-dependent magnetization study suggests that the magnetic property of La-doped BiFeO₃ samples varied from antiferromagnetic to ferromagnetic as the content of La-doped into BiFeO₃ increased from 0 to 20%. Unique temperature-dependent zero field cooling (ZFC) and field cooling (FC) magnetization behaviors were observed in 15% La-doped BiFeO₃ – its ZFC temperature-dependent magnetization being ferromagnetic and its FC temperature-dependent magnetization being antiferromagnetic. A possible mechanism of such an interesting M-T behavior is discussed.