Porous Alumina Assisted Anodizing of Ti/Nb Layers

The three-layer Al/Ti/Nb system onto Si substrates was magnetron sputter-deposited. The titanium/niobium layers in 0.2 M oxalic, orthophosphoric and tartaric solutions were alumina assisted 100 and 200 V potentiostatically anodized and galvanostatically reanodized in 0.5 M boric solution. Titanium oxide (Ti0
2
), niobium oxide (Nb
2
0
s
) and their mixture were obtained. The current-time and voltage-time response, morphology and composition were investigated.