An Ellipsometric-Electrochemical Cell: Initial Films on Titanium in Water and Methanol Solutions

Abstract

An ellipsometric‐electrochemical cell is described for simultaneous ellipsometric and electrochemical measurements of metal samples. The unique feature of this cell is the ability to prepare in one cavity with an appropriate etch‐polishing solution surfaces which within the experimental error of ellipsometric measurements approach an atomically clean state. The reaction product and etchant are washed away in a second cavity and in situ measurements of changes on the surface are made in a third cavity without exposing the sample to the atmosphere. It is demonstrated that Ti surfaces, which have the same optical constants as observed after ion bombardment cleaning and annealing in an ultra high vacuum system , can be prepared in the cell. Results are reported for the initial film growth on clean Ti in aqueous , aqueous , aqueous , and anhydrous solutions as a function of applied electrochemical potential.