Materials Data on Ti3Al5 by Materials Project

Abstract

Al5Ti3 is beta Cu3Ti-like structured and crystallizes in the orthorhombic Pmmm space group. The structure is three-dimensional. there are two inequivalent Ti sites. In the first Ti site, Ti is bonded to two equivalent Ti and ten Al atoms to form distorted TiTi2Al10 cuboctahedra that share corners with twelve equivalent TiTi2Al10 cuboctahedra, edges with four equivalent TiTi4Al8 cuboctahedra, edges with twenty AlTi8Al4 cuboctahedra, faces with eight TiTi2Al10 cuboctahedra, and faces with ten AlTi8Al4 cuboctahedra. Both Ti–Ti bond lengths are 2.91 Å. There are a spread of Ti–Al bond distances ranging from 2.73–2.95 Å. In the second Ti site, Ti is bonded to four equivalent Ti and eight Al atoms to form TiTi4Al8 cuboctahedra that share corners with four equivalent TiTi4Al8 cuboctahedra, corners with eight equivalent AlTi4Al8 cuboctahedra, edges with eight equivalent TiTi2Al10 cuboctahedra, edges with sixteen AlTi4Al8 cuboctahedra, faces with eight TiTi2Al10 cuboctahedra, and faces with ten AlTi8Al4 cuboctahedra. There are four shorter (2.81 Å) and four longer (2.82 Å) Ti–Al bond lengths. There are four inequivalent Al sites. In the first Al site, Al is bonded to eight Ti and four equivalent Al atoms to form AlTi8Al4 cuboctahedra that share corners with twelve AlTi8Al4 cuboctahedra, edges with eight equivalent TiTi2Al10 cuboctahedra, edges with sixteen AlTi4Al8 cuboctahedra, faces with eight TiTi2Al10 cuboctahedra, and faces with ten AlTi8Al4 cuboctahedra. All Al–Al bond lengths are 2.78 Å. In the second Al site, Al is bonded to four equivalent Ti and eight Al atoms to form AlTi4Al8 cuboctahedra that share corners with twelve AlTi8Al4 cuboctahedra, edges with eight equivalent AlTi6Al6 cuboctahedra, edges with sixteen TiTi2Al10 cuboctahedra, faces with four equivalent TiTi2Al10 cuboctahedra, and faces with fourteen AlTi8Al4 cuboctahedra. There are four shorter (2.81 Å) and four longer (2.87 Å) Al–Al bond lengths. In the third Al site, Al is bonded to four equivalent Ti and eight Al atoms to form AlTi4Al8 cuboctahedra that share corners with four equivalent AlTi4Al8 cuboctahedra, corners with eight equivalent TiTi4Al8 cuboctahedra, edges with eight equivalent TiTi2Al10 cuboctahedra, edges with sixteen AlTi8Al4 cuboctahedra, faces with six TiTi2Al10 cuboctahedra, and faces with twelve AlTi4Al8 cuboctahedra. All Al–Al bond lengths are 2.90 Å. In the fourth Al site, Al is bonded to six Ti and six Al atoms to form AlTi6Al6 cuboctahedra that share corners with twelve equivalent AlTi6Al6 cuboctahedra, edges with twelve TiTi2Al10 cuboctahedra, edges with twelve AlTi8Al4 cuboctahedra, faces with six TiTi2Al10 cuboctahedra, and faces with twelve AlTi8Al4 cuboctahedra.