Double-interface growth mode of fractal silver trees within replacement reaction

Crystals are generally considered to grow by attachment of atoms to the surface of growing grains. In this letter the authors present experimental results which demonstrate that silver amorphous phase deposits continuously and rapidly on the surface of formed nanocrystals in a replacement reaction on zinc plate. The amorphous phase interrupts the growth of nanocrystals by atom-by-atom attachment, instead, a fractal or dendritic growth still goes on by the deposition and crystallization of amorphous phase, and self-assembling of the crystallized nanograins. A double-interface mode is proposed to interpret the growth of fractal silver trees in AgNO3 solution. (c) 2006 American Institute of Physics.