Fabrication and magnetic properties of NiFe 2 O 4 nanorods

NiFe 2 O 4 nanorods have been successfully synthesized via thermal treatment of the rod‐like precursor fabricated by Ni‐doped α‐FeOOH, which was enwrapped by the complex of citric acid and Ni 2+ . The morphology evolution during the calcination of the precursor nanorods was investigated with transmission electron microscopy (TEM), and the phase and the magnetic properties of samples were analyzed through X‐ray diffraction (XRD) and vibrating sample magnetometer (VSM). The results indicated that the diameter of the NiFe 2 O 4 nanorods obtained ranged between 30 and 50 nm, and the length ranged between 2 and 3 μm. As the calcination temperature was up to 600°C, the coercivity, saturation magnetization, and remanent magnetization of the samples were 36.1 kA·m −1 , 27.2 A·m 2 ·kg −1 , and 5.3 A·m 2 ·kg −1 , respectively. The NiFe 2 O 4 nanorods prepared have higher shape anisotropy and superior magnetic properties than those with irregular shapes.