Template‐free synthesis of novel urchin‐like nickel microstructures with enhanced ferromagnetic properties

Novel urchin‐like nickel microstructures were prepared at 150°C via a facile hydrothermal method. Such urchin‐like particle is constructed by a spherical core and many spear‐shaped branches with length of 200–300 nm radiated from the centre. The synthetic process involved the chemical reduction of nickel ions by hydrazine hydrate and the oriented growth of nickel nanostructures under kinetic control independent of surfactant or external magnetic field. The magnetic properties were investigated at room temperature and the results demonstrated that the sample presented ferromagnetic properties with saturation magnetisation and coercivity values of ca . 44.6 emu/g and 257.7 Oe, respectively. These urchin‐like nickel microstructures are expected to bring new opportunities in application of magnetic storage and catalysis.