▎ 摘 要
We present evidence of moderate current density, when accompanied with high temperature, promoting migration of foreign atoms on the surface of multi-layer graphene. Our in situ transmission electron microscope experiments show migration of silicon atoms at temperatures above 800 degrees C and current density around 4.2 x 10(7) A/cm(2). Originating from the micro-machined silicon structures that clamp the freestanding specimen, the atoms are observed to react with the carbon atoms in the multi-layer graphene to produce silicon carbide at temperatures of 900-1000 degrees C. In the absence of electrical current, there is no migration of silicon and only pyrolysis of polymeric residue is observed. (C) 2015 AIP Publishing LLC.