Materials Data on TmAlO3 by Materials Project

Abstract

TmAlO3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Tm3+ is bonded to six equivalent O2- atoms to form distorted TmO6 octahedra that share corners with six equivalent AlO5 trigonal bipyramids and edges with six equivalent TmO6 octahedra. All Tm–O bond lengths are 2.23 Å. Al3+ is bonded to five O2- atoms to form AlO5 trigonal bipyramids that share corners with six equivalent TmO6 octahedra and corners with six equivalent AlO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 62°. There is two shorter (1.83 Å) and three longer (1.98 Å) Al–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to three equivalent Tm3+ and one Al3+ atom to form a mixture of distorted edge and corner-sharing OTm3Al tetrahedra. In the second O2- site, O2- is bonded in a trigonal planar geometry to three equivalent Al3+ atoms.