Transition metal attenuated mechanism for protective alumina formation from first principles.

ABSTRACT: A mechanistic perspective on the growth of protective oxides on high temperature alloys at elevated temperatures is provided. Early, defect rich transient alumina is understood to form by outwards diffusion of oxygen vacancies and electrons. The impact of transition metal (TM) ions (Sc, Ti, V, Cr, Mn, Fe, Co, Ni) on the oxygen vacancy diffusion and electron transport in α-alumina was studied by employing density functional theory. Activation energies for electron transfer E _A(ET) between oxygen vacancies in pure as well as TM doped α-alumina were subject to analysis, and similarly so for the TM and charge dependent activation energy for oxygen vacancy diffusion E _A(V _O). E _A ^Q (ET) were found to be ∼0

SUBMITTER: Babic V 

PROVIDER: S-EPMC9091954 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature