Novel magnetic vortex nanorings/nanodiscs: Synthesis and theranostic applications

Liu Xiao-Li^a),^b), Yang Yong^a), Wu Jian-Peng^b), Zhang Yi-Fan^b), Fan Hai-Ming^b), Ding Jun†^a)

(a) A typical hysteresis loop of a ferromagnetic/ferrimagnetic material. (b) Schematic illustration of the dependence of coercivity on particle size. (c) and (d) Typical hysteresis loops of a superparamagnetic nanomaterial and a ferromagnetic/ferrimagnetic nanomaterial. Under a magnetic field, the magnetic moments of the domains of ferromagnetic particles and single-domain superparamagnetic particles are aligned. After removal of the magnetic field, ferromagnetic particles maintain a net magnetization.