Materials Data on Ta4AlC3 by Materials Project

Abstract

Ta4AlC3 is MAX Phase structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Ta sites. In the first Ta site, Ta is bonded in a 3-coordinate geometry to three equivalent Al and three equivalent C atoms. All Ta–Al bond lengths are 2.89 Å. All Ta–C bond lengths are 2.17 Å. In the second Ta site, Ta is bonded to six C atoms to form a mixture of edge and corner-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.22 Å) and three longer (2.25 Å) Ta–C bond lengths. Al is bonded in a 12-coordinate geometry to six equivalent Ta atoms. There are two inequivalent C sites. In the first C site, C is bonded to six Ta atoms to form a mixture of edge and corner-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the second C site, C is bonded to six equivalent Ta atoms to form a mixture of edge and corner-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 1°.