Materials Data on Sm2Zr2O7 by Materials Project

Abstract

Sm2Zr2O7 crystallizes in the orthorhombic Pmma space group. The structure is three-dimensional. there are two inequivalent Sm3+ sites. In the first Sm3+ site, Sm3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are four shorter (2.24 Å) and two longer (2.39 Å) Sm–O bond lengths. In the second Sm3+ site, Sm3+ is bonded to six O2- atoms to form a mixture of distorted corner and edge-sharing SmO6 octahedra. The corner-sharing octahedral tilt angles are 72°. There are four shorter (2.34 Å) and two longer (2.35 Å) Sm–O bond lengths. There are two inequivalent Zr4+ sites. In the first Zr4+ site, Zr4+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Zr–O bond distances ranging from 2.17–2.60 Å. In the second Zr4+ site, Zr4+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Zr–O bond distances ranging from 2.22–2.39 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to four Zr4+ atoms to form OZr4 tetrahedra that share corners with sixteen OZr4 tetrahedra and edges with six OSmZr3 tetrahedra. In the second O2- site, O2- is bonded to one Sm3+ and three Zr4+ atoms to form a mixture of corner and edge-sharing OSmZr3 tetrahedra. In the third O2- site, O2- is bonded to two equivalent Sm3+ and two equivalent Zr4+ atoms to form a mixture of corner and edge-sharing OSm2Zr2 tetrahedra. In the fourth O2- site, O2- is bonded to two equivalent Sm3+ and two equivalent Zr4+ atoms to form a mixture of corner and edge-sharing OSm2Zr2 tetrahedra. In the fifth O2- site, O2- is bonded to three Sm3+ and one Zr4+ atom to form distorted OSm3Zr tetrahedra that share corners with fourteen OZr4 tetrahedra and edges with four OSmZr3 tetrahedra.