Magnetic field controlled particle-mediated growth inducing icker-like silver architectures

Abstract

An unusually anisotropic growth or quasi-one-dimension growth of silver architectures can be achieved when an external magnetic field is applied to a simple replacement reaction. The external magnetic field greatly promotes the growth of trunks along 〈111〉 directions but weakens the growth of branches along 〈311〉 directions, resulting in a silver icker-like architectures. The influences of the external magnetic field, solution concentration and reaction time have been investigated in detail. The formation of silver icker-like architectures could be attributed to shape magnetic anisotropy and fast complex micro-magnetohydrodynamic (MHD) convection effects induced by the external magnetic field of the nanoparticles possessing a truncated octahedron structure. Moreover, the magnetic field effect on the crystal growth of nanostructures generally involves the ion-mediated growth process or the aggregations of numerous nanoparticles along the magnetic field directions because of dipolar interactions. Our experiments and discussions, however, indicate that metal crystals are grown through a multistep particle-mediated growth process with the nanoparticles as basic building blocks.