Materials Data on Sr2YAlCu2O7 by Materials Project

Abstract

YSr2AlCu2O7 crystallizes in the orthorhombic Ima2 space group. The structure is three-dimensional. Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.43–3.02 Å. Y3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Y–O bond distances ranging from 2.36–2.52 Å. Cu2+ is bonded to five O2- atoms to form distorted CuO5 square pyramids that share corners with four equivalent CuO5 square pyramids and a cornercorner with one AlO4 tetrahedra. There are a spread of Cu–O bond distances ranging from 1.94–2.50 Å. Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with two equivalent CuO5 square pyramids and corners with two equivalent AlO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.76–1.81 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to three equivalent Sr2+, one Cu2+, and one Al3+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sr2+ and two equivalent Al3+ atoms. In the third O2- site, O2- is bonded in a 6-coordinate geometry to two equivalent Sr2+, two equivalent Y3+, and two equivalent Cu2+ atoms. In the fourth O2- site, O2- is bonded to two equivalent Sr2+, two equivalent Y3+, and two equivalent Cu2+ atoms to form a mixture of distorted face and corner-sharing OSr2Y2Cu2 octahedra. The corner-sharing octahedra tilt angles range from 1–67°.