Materials Data on AlCoO3 by Materials Project

Abstract

CoAlO3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Co3+ is bonded to five O2- atoms to form CoO5 trigonal bipyramids that share corners with six equivalent AlO6 octahedra and corners with six equivalent CoO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 64°. There is three shorter (1.82 Å) and two longer (1.94 Å) Co–O bond length. Al3+ is bonded to six equivalent O2- atoms to form distorted AlO6 octahedra that share corners with six equivalent CoO5 trigonal bipyramids and edges with six equivalent AlO6 octahedra. All Al–O bond lengths are 2.02 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to three equivalent Co3+ atoms. In the second O2- site, O2- is bonded to one Co3+ and three equivalent Al3+ atoms to form a mixture of edge and corner-sharing OAl3Co tetrahedra.