DOE OSTI2020
Yb8GaAl3 is Cubic Laves-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are four inequivalent Yb sites. In the first Yb site, Yb is bonded to six Yb, two equivalent Ga, and four Al atoms to form a mixture of corner, edge, and face-sharing YbYb6Al4Ga2 cuboctahedra. There are a spread of Yb–Yb bond distances ranging from 3.18–3.20 Å. Both Yb–Ga bond lengths are 3.73 Å. There are a spread of Yb–Al bond distances ranging from 3.73–3.76 Å. In the second Yb site, Yb is bonded to six Yb, one Ga, and five Al atoms to form a mixture of corner, edge, and face-sharing YbYb6Al5Ga cuboctahedra. There are four shorter (3.18 Å) and two longer (3.19 Å) Yb–Yb bond lengths. The Yb–Ga bond length is 3.76 Å. There are four shorter (3.73 Å) and one longer (3.75 Å) Yb–Al bond lengths. In the third Yb site, Yb is bonded to six Yb, three equivalent Ga, and three equivalent Al atoms to form YbYb6Al3Ga3 cuboctahedra that share corners with eighteen YbYb6Al4Ga2 cuboctahedra, edges with six equivalent YbYb6Al3Ga3 cuboctahedra, and faces with eighteen YbYb6Al4Ga2 cuboctahedra. All Yb–Ga bond lengths are 3.73 Å. All Yb–Al bond lengths are 3.73 Å. In the fourth Yb site, Yb is bonded to six Yb and six Al atoms to form YbYb6Al6 cuboctahedra that share corners with eighteen YbYb6Al4Ga2 cuboctahedra, edges with six equivalent YbYb6Al6 cuboctahedra, and faces with eighteen YbYb6Al4Ga2 cuboctahedra. All Yb–Al bond lengths are 3.73 Å. Ga is bonded in a 12-coordinate geometry to twelve Yb atoms. There are three inequivalent Al sites. In the first Al site, Al is bonded in a 12-coordinate geometry to twelve Yb atoms. In the second Al site, Al is bonded in a 12-coordinate geometry to twelve Yb atoms. In the third Al site, Al is bonded in a 12-coordinate geometry to twelve Yb atoms.