2 Role of Surface Analysis

Since surface energy γ is related to interaction of molecules, tribological behaviors at small scale are essentially sensitive to the surface chemical structure. Figure 2.1 indicates the characteristics of surface analytical tools as viewed from size, time and resolving power. Since tribology is dynamic phenomenon, the time required for measurement should be short enough to identify state of surface. At present, FTIR and Raman spectroscopy can be operated at the time resolution of nano and picosecond, but in this case the spatial resolution will be lowered. Therefore, the axis of time in Figure 2.1 is hard to describe.

Interpretation of tribological processes can only be made by the precise measurement of surface phenomena. For this purpose, the authors have dealt with HR-TEM, FIM, SPM, XANES, and ToF-SIMS, all of which are powerful tools for the study of micro and nanotribology. Recent progress in some of those studies is described in this chapter.