Photoelectrochemical study of the semiconductive properties of anodic oxide films on titanium-aluminum alloys

The properties (a band gap E-g and a flat band potential E-fb) of anodic ox ide films, which were formed on several titanium-aluminum alloys (10-50 at. % Al) in solutions of various composition, are studied by photoelectrochem ical method. It is found that E-g is virtually independent of alloy composi tion and only slightly depends on the solution composition. At an Increase in the pH value in a domain of 3 to 13, a linear decrease in E-fb is observ ed on pure titanium and on the alloy with 10 at. % Al; for the alloy with 5 0 at. % Al, the linearity is broken.