Abstract
A series of CoNi based hierarchical microspheres with different surface morphologies, including litchi‐like, seed of plane tree‐like and waxberry‐like shapes, are obtained via surface nucleation of carbon quantum dots (CQDs). Taking both the synergistic benefits of paramagnetic CoNi microspheres and surface architecture, the resulting CoNi microspheres exhibit enhanced interparticle friction for enhancing their MR effects compared with smooth surface microspheres. This work is reported by Wen Ling Zhang, Jingquan Liu and co‐workers in article number 1800164.