On the Growth of Copper Whiskers by Halide Reduction and Their Perfection

Defect structures of copper whiskers, grown by hydrogen reduction of copper iodide, whose diameter ranges from several hundreds Å to one micron and from 20 to 100 µ, have been examined under 100, 500 and 1000 kV electron microscopes and a fine focus X-ray diffraction microscope, respectively, in order to study their growth process and peculiar mechanical properties. Observational results show that there is no dislocation in a large number of copper whiskers having not only straight shape but also kinked, curved, spiral and irregular-thickness ones. On a few specimens, dislocations with various forms such as straight, jogy, helical, tangled and of loop are observed. In some whiskers, dot-like defects are observed over the whole of them. At tips of the whiskers, the fragment containing impure crystallites and also the lattice defects are often observed, which may be associated with the growth mechanism of their tip growth.