Caractéristiques Courant-Tension Des Structures Ti/TiO2/Électrolyte Et Ti/TiO2/Métal: Effet Schottky Et Claquage

Anodic layers of TiO₂ were made with a potentiostatic setting and voltages from 1 to 90 V in 1 N sulphuric acid. The current-applied voltage characteristics of the structures Ti/TiO₂/Au and Ti/TiO₂/electrolyte are compared and analysed with the Schottky mechanism. The barrier heights calculated for the rectifying interfaces TiO₂-Au and TiO₂-electrolyte are respectively 1.2±0.1 eV and 0.88±0.05 eV. Three domains of voltage were distinguished for the anodic oxidation of titanium in the potentiostatic mode as follows: from 1 to 10 V corresponding to a natural oxide thin layer and the beginning of anodic oxidation; from 10 to 90 V corresponding to oxidation with electronic breakdown; beyond 90 V relating to oxidation accompanied by thermal breakdown.