Synthesis and Magnetic Properties of Maghemite (γ-Fe2O3) Short-Nanotubes

We report a rational synthesis of maghemite (gamma-Fe2O3) short-nanotubes (SNTs) by a convenient hydrothermal method and subsequent annealing process. The structure, shape, and magnetic properties of the SNTs were investigated. Room-temperature and low-temperature magnetic measurements show that the as-fabricated gamma-Fe2O3 SNTs are ferromagnetic, and its coercivity is nonzero when the temperature above blocking temperature (T (B)). The hysteresis loop was operated to show that the magnetic properties of gamma-Fe2O3 SNTs are strongly influenced by the morphology of the crystal. The unique magnetic behaviors were interpreted by the competition of the demagnetization energy of quasi-one-dimensional nanostructures and the magnetocrystalline anisotropy energy of particles in SNTs.