D. Gharailou, A. Abbasi,
Volume 12, Issue 3 (9-2015)
Abstract
Effect of electro migration on crystal structures of platinum nanowire (Nano bridge) during Nano-gap
formation is investigated by means of Transmission Electron Microscopy (TEM). Selected area diffraction patterns as
well as bright field images are used for this investigation. There were severely recessions in the polycrystalline Nano
bridge and crystal structures around the nanogap changed completely during electro migration. Due to Joule heating,
original small crystal with random orientation disappeared and newly crystals with a preferred orientation grew. They
have [111] orientations (respect to beam direction) with slight misorientations. α and θ was defined to calculate the
misorientation and used to represent Nano-gap formation mechanism. The calculation gives the breaking of Nano
bridge occurred along grain boundaries in most of Nano bridges. The controlling system during eletromigration may
affect on the shapes of tips so that the shape of tips in Nano bridges, in which feedback control is applied, is more
symmetric than others. The effect of temperature on atomic diffusivity might be the reason of the behaviour. {422}
could be a preferred surface plane for mass transport in platinum Nano bridge in which atoms move along it
