Synthesis and Magnetic Properties of Single‐Crystals of MnFe₂O₄ Nanorods

Abstract

Abstract Single‐crystals of MnFe 2 O 4 nanorods with an average diameter of 20 nm and length of 250 nm were synthesized by a hydrothermal process at 180 °C after 12 h. High‐resolution transmission electron microscopy (HRTEM) and electron diffraction (ED) analysis revealed that the nanorods grow along the [110] axis, which is one of the easy magnetization axes of the material MnFe 2 O 4 . It was found that the nanorods exhibited a saturation magnetization ( Ms ) of 68.02 emu/g, which is much higher than that of quasi‐spherical particles of MnFe 2 O 4 , prepared by other approaches such as solid‐state reaction methods ( Ms = 36.7 emu/g), and coprecipitation processes followed by annealing in vacuo at 400 °C ( Ms = 24.4 emu/g). The oriented growth along the easy magnetization axis of MnFe 2 O 4 was suggested to be responsible for the improvement of magnetic properties of MnFe 2 O 4 nanorods. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)