Growth of the Nanostructured Titanium Oxide by Anodization of Ti/Cu/Ti System

Abstract

The study investigates the impact of the electrolyte composition and anodization conditions on titanium oxide microstructures, analyzing their influence on a trilayer titanium/copper/titanium system. The electrolytes used for anodization had different concentrations of ammonium fluoride and water. The quality and stability of the oxide growth were controlled by monitoring changes in the current density curves during anodization. In water-rich electrolytes, the titanium oxide layer exhibits improved structural quality but reduced layer conductivity, leading to electrical breakdown and destruction of the layer through rapid electrical discharge. Under equilibrium conditions between fluoride ions and water, scanning electron microscope images demonstrate nanoporous structures with inner pore diameters exhibiting a log-normal distribution, with median sizes ranging from 15 to 70 nm across voltage ranges. Linear correlations between the inner pore diameters and the applied voltage are observed, notably in certain electrolytes, indicating stable processes and high quality of the nanopatterned oxide.