Institute of Industrial Science, University of Tokyo, Tokyo, Japan.
Sci Rep. 2012;2:623. doi: 10.1038/srep00623. Epub 2012 Sep 3.
Dislocation is a lattice imperfection of crystalline materials. Dislocation movement is induced during plastic deformation and influences the mechanical properties. Although the role of dislocation in mechanical properties has been well understood, the role of dislocation in electrical properties is completely lacking. Only Matthiessen's rule addresses the electrical influence of dislocations at the macroscale. Here, we show that the electrical conductance change due to dislocations and show their movements through in situ observation of a gold nanocontact. The density of the dislocations in the gold nanocontact did not affect the electrical conductance. The repeated and discrete dislocation movements resulted in an electrical conductance oscillation. Our results demonstrate how dislocations and their movements affect electric conductance at the nanoscale. This instability issue will cause a big problem for future electric devices such as ultra low power electric devices and nanowire photovoltaic devices.
位错是晶体材料的晶格缺陷。位错运动是在塑性变形过程中产生的，并影响材料的力学性能。尽管位错在力学性能中的作用已经得到很好的理解，但位错在电学性能中的作用却完全缺失。只有 Matthiessen 定律在宏观尺度上讨论了位错对电学性能的影响。在这里，我们通过对金纳米触点的原位观察，展示了由于位错引起的电导变化及其运动。金纳米触点中位错的密度并不影响电导。重复的和离散的位错运动导致电导的振荡。我们的结果展示了位错及其运动如何影响纳米尺度的电导。这个不稳定性问题将对未来的电子设备，如超低功耗电子设备和纳米线光伏器件，造成很大的问题。
