Thickness-dependent stabilization of tetragonal ZrO2 in oxidized zirconium

Raman study of oxide layers on zirconium alloys using 18O tracers

“…Raman spectroscopy was used to analyse distribution of 18 O isotope in corrosion layers of the alloys. Layered distribution of 18 O was observed in case of Zr1Nb samples; Zircaloy-4W had 18 O present only at metal/oxide interface. This observation is attributed to differing kinetic transitions, which influence transport of oxygen through oxide layer.…”

“…However, the diffusion of oxygen towards metal/oxide interface is not yet completely clarified [4,10,11,[13][14][15]17]. One possible way to investigate this phenomenon is a two-stage oxidation, when an alloy with previously prepared oxide layer (containing a natural proportion of 16 O isotope) is further oxidised in isotopically pure medium in which 18 O isotopes are present in water molecules.…”

Untangling competition between epitaxial strain and growth stress through examination of variations in local oxidation

“…Alternatively, transmission electron microscopy (TEM) investigations 19,28,46,47 only focus on a few oxide grains formed on a single randomly selected substrate grain, making a statistical analysis of possible orientation relationships very difficult. By definition, these techniques also require the production of electron transparent samples, which is known to alter the microstructure of such stress-stabilised oxide films 48,49 .…”

Untangling competition between epitaxial strain and growth stress through examination of variations in local oxidation

“…Alternatively, transmission electron microscopy (TEM) investigations [7][8][9] only focus on a few oxide grains formed on a single randomly selected substrate grain, making a statistical analysis of possible orientation relationships time-consuming and difficult. By definition, these techniques also require the production of electron transparent samples, which is known to alter the microstructure of such stress-stabilised oxide films 10,11 .…”

“…This leads to the rapid growth of a fresh protective oxide layer and the process repeats in a cyclic manner. The build-up and subsequent release of the high compressive stresses, as the oxide grains move away from the metal-oxide interface, is proposed to lead to the breakdown of the columnar microstructure and the occurrence of phase transformations between the metastable and stable oxide phases 10,[42][43][44][49][50][51] . The role of these oxide phase transformations in the corrosion process is still unclear-the majority of studies suggest they have detrimental effects by causing cracking of the oxide film 39,42,44 , although a few report beneficial effects 51 .…”