Hydrogen solubility in zirconium intermetallic second phase particles

TL;DR

This study uses density functional theory to predict hydrogen solubility in various zirconium intermetallic phases, revealing which phases are more stable for hydrogen trapping and implications for nuclear materials.

Contribution

It provides the first computational comparison of hydrogen solution enthalpies across multiple Zr intermetallic compounds, highlighting phases with lower energy sites for hydrogen.

Findings

Zr-rich phases with Cu, Fe, Ni, Sn are more stable for H.

Mo and Cr phases do not favor hydrogen solution.

Most stable H sites involve high Zr coordination, often four Zr tetrahedra.

Abstract

The enthalpies of solution of H in Zr binary intermetallic compounds formed with Cu, Cr, Fe, Mo, Ni, Nb, Sn and V were calculated by means of density functional theory simulations and compared to that of H in {\alpha}-Zr. It is predicted that all Zr-rich phases (formed with Cu, Fe, Ni and Sn), and those phases formed with Nb and V, offer lower energy, more stable sites for H than {\alpha}-Zr. Conversely, Mo and Cr containing phases do not provide preferential solution sites for H. In all cases the most stable site for H are those that offer the highest coordination fraction of Zr atoms. Often these are four Zr tetrahedra but not always. Implications with respect to H-trapping properties of commonly observed ternary phases such as Zr(Cr,Fe)2, Zr2(Fe,Ni) and Zr(Nb,Fe)2 are also discussed.