High hydrogen isotopes permeation resistance in (TiVAlCrZr)O multi-component metal oxide glass coating

Developing ceramic coating with high hydrogen isotopes permeation resistance is an urgent task in many fields such as fusion reactor systems, hydrogen storage/transportation, and fuel cell. In this work, a (TiVAlCrZr)O multi-component metal oxide glass (MCMOG) coating is developed as a new type of hydrogen isotopes permeation barrier (HIPB), and the diffusion behavior of deuterium in MCMOG is studied for the first time. Compared with the deuterium permeation reduction factor (DPRF) of 51 for amorphous alumina coating (at 587 °C in 0.65 µm), the 29 nm dense MCMOG coating has around 27 times enhancement with DPRF of 1420 at 550 °C. Based on first-principles calculations, we show that the significantly suppressed deuterium permeation in MCMOGs is attributed to the sluggish diffusion of deuterium arising from the highly rugged energy landscape, which is induced by the diversity of electronic band structures near the Fermi level. In addition, oxygen vacancies strongly affect PRF, where the PRF of the fully oxidized MCMOG layer (29 nm) is around 200 times compared to that of MCMOG with the same thickness containing oxygen vacancies. Therefore, dense MCMOG is a new promising HIPB material.