EXPERIMENTAL-STUDY ON POINT-CONTACT TRANSPORT PHENOMENA USING THE ATOMIC-FORCE MICROSCOPE

Point contact transport phenomena have been studied thermally and elec trically in order to realize submicrometer-scale thermal measurement u sing the atomic force microscope (AFM). A small thermocouple cantileve r probe made by depositing gold film on sharpened nickel wire was used to investigate point contact heat transfer. Although it was impossibl e to detect the point contact heat transfer because of thermal conduct ion through air, the thermocouple probe combined with the AFM yielded thermal images of a small heater of 20 x 20 mu m. On the other hand, t he electric conductive cantilever was made to probe the electron trans port through metallic point contact. The experimental correlation betw een the point contact resistance and force applied on the cantilever s hows a different tendency compared to the conventional model, where el astic or plastic deformation, and continuum or mesoscopic electron tra nsport, are assumed. Also, clear contrast in electrical conductivity w as visualized on the composite material by measuring electric conducta nce at the point contact.