Dynamic Observation of the Thinnest Gold Nano-Bridge by Newly Developed UHVTEM

Abstract The nano-structure science have become popular as the nano-fabrication technology has progress recently. Among the nano-structures, the nano-wires have been attracted attention because they show quantized conductance which would be used in quantum devices[l]. The quantized conductance has been observed even at room temperature with the nano-wires prepared by tip-indentation in scanning tunneling microscope [2-4]. However, the direct observation of the nano-wires has not been examined because of lack of their stability and difficulty of specimen preparation. We have generated a gold thin wire with the thickness ranged 0.8-2 nm, referred to as a nano bridge (NB)[5], in an ultrahigh vacuum transmission electron microscope (UHVTEM) [6]. The NB is stable at room temperature and shows good reproducibility. The shape of NB is surprisingly uniform (see Fig. 2). The structure is stabilized by stable hexagonally-closed-pack (hcp) planes for the NB of 2 nm in thickness [5]. The well-defined structure provide a good opportunities for applied and theoretical studies.