Measurements of the surface diffusion coefficient in iron-carbon alloys using Focused Ion Beam milling and High Temperature Laser Scanning Confocal Microscopy

The use of high-temperature confocal microscopy, shows a great potential as a means of measuring surface diffusion coefficients in metallic systems[1]. This new experimental approach has an advantage as contaminants entering the system are significantly reduced. Surface diffusion coefficients can be determined at temperatures approaching the melting point. Mullins and King[2-5] have shown that surface undulations can be related to the surface diffusion coefficient of a metal. In this study, focused ion beam (FIB) milling has been used to introduce geometrically well-defined undulations on the surface of iron and iron carbon alloys. High temperature laser scanning confocal microscopy was then used to observe the decay in situ in real time.