The objective of this renewal grant is to exploit the microscopic techniques developed in a previously funded effort for high resolution, topographic imaging with concurrent optical, electrochemical, photoelectrochemical, and fluorescence mapping. The techniques are based on novel modifications of the Near Field Optical Scanning Microscope (NSOM, Topometrix) to obtain shear force feedback control with a piezoelectric tuning fork. In the past work resolutions were achieved for the above functional microscopies at or just below 100 nm. This effort extends the resolution to 10 nm or below. The precursor sites leading to pitting corrosion are explored on high purity titanium and on aluminum alloys. This should facilitate in situ and ex situ evaluation of surface treatments to mitigate pitting corrosion. A second objective uses the high-resolution capabilities of the instrumentation to identify corrosion of microstructured microelectronic and magnetic storage assemblies. %%% As the dimension of these materials decrease, corrosion becomes increasingly important, and techniques to explore heterogeneous surfaces are needed. Scanning electrochemical microscopy with concurrent topographic mapping is an excellent technique being developed for these studies. ***
