Transport properties of Ce-doped nickel oxide and relevance on the thermal growth of oxide scales on CeO2-coated nickel

Thermal Oxidation Kinetics of Nickel and Dilute (Ni-Al) Alloys

“…, it was shown that the chemical diffusion coefficient of undoped and Al-doped Ni 1-x O single crystals can be expressed by the relation (Mahiouz, 2019)…”

“…One may then use the anion sublattice as frame of reference for motion of cations and defects. When an oxide (AO-B exposed to an oxygen chemical potential gradient (Eq.1), a flux of vacancies (J V ) occurs in the sample toward the side showing a low oxygen activity (a O = P O2 1/2 ), coupled to an opposite flux of cations (J i ) (Petot-Ervas, 1990;Halem, 2016;Philibert, 1972;Farhi, 1978;Atkinson, 1981;Mahiouz, 2019;Schmalzried, , 1986.…”

“…Therefore, substituting Eq.10 in Eq.8, allows to show that the shift velocity of the oxidation front in an oxide AO-BO exposed to an oxygen chemical potential gradient can be written Petot-Ervas, 1990), (Halem, 2016;(Mahiouz, 2019):…”

“…This study was performed with undoped and Al (0.11 wt%)-doped Ni 1-x O single crystals, machined to obtain parallelepipedic samples (3x2x2mm 3 ). Since the diffusing species are electrically charged, their fluxes may then be due to a gradient of oxygen activity (a O ), with a O =P O2 1/2 (Eq.10), or to an applied electric field (E) (Halem, 2016), (Mahiouz, 2019), (Monceau,1994):…”