Conductance and series resistance measurements of polyaniline/p-Si and polypyrrole/InP junction devices

This paper reports on the structural and electrical characteristics of Joule heat welds in ultrathin Pt wires with diameters of 600–800 nm. The wires have a bamboo structure where the crystal grains are aligned only in the axial direction. They were welded together in a self-completed manner in air by Joule heating. The electrical resistance of the welded wire system was measured using a potential drop technique. It was found by transmission electron microscope observations that the region affected by welding was very narrow and it appeared that a new grain boundary had been created in this region. Moreover, the welds were found to have good electrical characteristics and the electrical resistance at the weld depended on its cross-sectional area.