Role of oxygen in materials properties of yttrium trihydride

• The mechanism of oxygen-caused stabilization of fcc YH3 compound is presented.
• The structural and electronic properties are reported.
• The possibility for band gap engineering by varying oxygen content is proposed.

Numerous experiments have shown that the oxygen-free films of YH3 possess the face-centered cubic (fcc) structure only at high pressures whereas oxygen-containing YH3 films crystallize into the fcc lattice at ambient conditions. In this report, by means of first-principles simulations, we provide a detail understanding of the role of oxygen in stabilization of the fcc YH3 under normal pressure. We performed the oxygen position preferences screening within the fcc unit cell along with geometrical optimization series and verified the major stability conditions. The main aggregate and electronic characteristics have been calculated in order to gain an insight into how the Y–O bond activation and coordination in the metallic matrix create new materials properties. The possibility of the compositional architecture on the base of fcc crystalline silicon and oxygen-containing YH3 compounds has been suggested.