NiFe_2O_4-BiFeO_3纳米管的制备与磁电特性研究

Synthesis and Magnetoelectric Properties of NiFe_2O_4-BiFeO_3 Nanotubes

采用溶胶–凝胶法在多孔氧化铝模板的纳米孔洞中成功地合成了x Ni Fe2O4-(1–x)Bi Fe O3(NFO-BFO)复合纳米管阵列。扫描电镜照片显示纳米管的外径约为70 nm,内径约为50 nm,长度约为80?m。X射线衍射图谱显示,通过自组装形成了钙钛矿结构的铁电相BFO和尖晶石结构的铁磁相NFO。磁性和铁电性的测试结果表明,复合纳米管具有明显的室温铁磁性和电极化性能,且易磁化方向沿着纳米管的长轴方向。随着NFO复合比例的增加,纳米管阵列的磁性和电极化性能逐渐增强。NFO对复合纳米管阵列铁磁贡献的计算结果表明,NFO-BFO纳米管阵列中存在着磁电耦合效应。

x NFO-（1–x）BFO（NFO-BFO） nanotube arrays were fabricated by means of Sol-Gel method utilizing nanochannel alumina as templates. Scanning electron microscopy study revealed that the outer diameter of nanotube was about 70 nm, and the internal diameter was about 50 nm, the length was about 80 ？m. Meanwhile, ferroelectric phase BFO of perovskite structure and ferromagnetic phase NFO of spinel structure were formed through self-assembly growth in X-ray diffraction patterns. Significant ferromagnetic and polarized characteristics of nanotube arrays were demonstrated by means of magnetic and ferroelectric measurement at room temperature, and the direction of easy magnetization was along the long axis. With increasing ratio of NFO, the magnetic and polarized properties of nanotube arrays increased gradually. The calculation results of NFO＇s ferromagnetic contribution indicated that magnetoelectric coupling effect existed in the NFO-BFO composite nanotube arrays.