Materials Data on SrEu2Fe2O7 by Materials Project
SrEu2Fe2O7 crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. Sr2+ is bonded to twelve O2- atoms to form distorted SrO12 cuboctahedra that share corners with four equivalent SrO12 cuboctahedra, faces with four equivalent SrO12 cuboctahedra, and faces with eight equivalent FeO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.62–3.12 Å. Eu3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Eu–O bond distances ranging from 2.31–2.61 Å. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with five equivalent FeO6 octahedra and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 6–24°. There are a spread of Fe–O bond distances ranging from 1.97–2.14 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to three equivalent Eu3+ and one Fe3+ atom. In the second O2- site, O2- is bonded in a 6-coordinate geometry to two equivalent Sr2+, two equivalent Eu3+, and two equivalent Fe3+ atoms. In the third O2- site, O2- is bonded in a 6-coordinate geometry to four equivalent Sr2+ and two equivalent Fe3+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sr2+, two equivalent Eu3+, and two equivalent Fe3+ atoms. In the fifth O2- site, O2- is bonded to two equivalent Sr2+, two equivalent Eu3+, and two equivalent Fe3+ atoms to form distorted edge-sharing OSr2Eu2Fe2 octahedra.