6533b859fe1ef96bd12b7689

RESEARCH PRODUCT

Investigation on passivity of titanium under steady-state conditions in acidic solutions

Xin DaiZhonglin JiangZhonglin JiangHugh Middleton

subject

Materials sciencePassivityInorganic chemistryOxidechemistry.chemical_elementEquivalent oxide thicknessElectrolyteCondensed Matter Physicschemistry.chemical_compoundchemistryLattice (order)General Materials SciencePolarization (electrochemistry)Electrode potentialTitanium

description

Abstract The passivity of titanium was studied using potentiostatic polarization combined with Mott–Schottky analysis in acidic solutions. The oxide layer was characterized as an n-type semiconducting, oxygen deficient oxide (TiO1.993–1.996) with a donor density in the range of 1019–1020 cm−3 depending on electrode potential and electrolyte pH. The calculated thickness for the inner oxide layer was in the range of 1–4 nm, increasing linearly with applied potential and exponentially with electrolyte pH. The potential- and pH-dependence of the inner oxide thickness was interpreted by a modified point defect model for the migration-controlled oxide growth, in which the rate-determining step in the passive film growth processes was assumed to be the donor lattice migration.

https://doi.org/10.1016/j.matchemphys.2010.12.028