From Hot‐Injection Synthesis to Heating‐Up Synthesis of Cobalt Nanoparticles: Observation of Kinetically Controllable Nucleation

Almost equal: Particle nucleation in the widely studied hot-injection synthesis of magnetic cobalt nanoparticles (see TEM image) was found to take place well after the injection and to be temperature-controlled. This insight into particle nucleation led to a technologically relevant heating-up synthesis of nearly monodisperse cobalt nanoparticles on a multigram scale. The particle size could be tuned simply by adjusting the heating rate.