TY - JOUR

T1 - Diffusion in doped and undoped amorphous zirconia

AU - Owen, Megan

AU - Rushton, Michael

AU - Evitts, Lee J.

AU - Claisse, Antoine

AU - Puide, Mattias

AU - Lee, Bill

AU - Middleburgh, Simon

PY - 2021/11

Y1 - 2021/11

N2 - Grain boundaries in ZrO₂ may act as favourable pathways for species, such as oxygen and hydrogen, which play an important role in corrosion when compared with volume diffusion through the bulk of the crystalline material. It is known that segregation of impurity and alloying elements can lead to highly-doped grain boundaries with amorphous structure. Here, these amorphous structures are compared to crystalline materials of equivalent composition. Atomic scale modelling methods have been used to analyse diffusion in undoped systems and zirconia cells doped with 5.3 at. % and 11.0 at. % of trivalent lanthanide species. Diffusion coefficients, pre-exponential factors and activation energies are reported. Oxygen diffusivity was markedly increased in amorphous doped and undoped ZrO₂ systems compared to equivalent undoped crystalline systems. Similar diffusivities are reported between amorphous and crystalline doped systems at the concentrations considered.

AB - Grain boundaries in ZrO₂ may act as favourable pathways for species, such as oxygen and hydrogen, which play an important role in corrosion when compared with volume diffusion through the bulk of the crystalline material. It is known that segregation of impurity and alloying elements can lead to highly-doped grain boundaries with amorphous structure. Here, these amorphous structures are compared to crystalline materials of equivalent composition. Atomic scale modelling methods have been used to analyse diffusion in undoped systems and zirconia cells doped with 5.3 at. % and 11.0 at. % of trivalent lanthanide species. Diffusion coefficients, pre-exponential factors and activation energies are reported. Oxygen diffusivity was markedly increased in amorphous doped and undoped ZrO₂ systems compared to equivalent undoped crystalline systems. Similar diffusivities are reported between amorphous and crystalline doped systems at the concentrations considered.

KW - ZrO₂

KW - Amorphous

KW - Grain boundaries

KW - Diffusion

KW - Lanthanides

U2 - 10.1016/j.jnucmat.2021.153108

DO - 10.1016/j.jnucmat.2021.153108

M3 - Article

VL - 555

JO - Journal of Nuclear Materials

JF - Journal of Nuclear Materials

SN - 0022-3115

M1 - 153108

ER -