Materials Data on Y2Hf2O7 by Materials Project

Abstract

Y2Hf2O7 crystallizes in the tetragonal P4_12_12 space group. The structure is three-dimensional. Y3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Y–O bond distances ranging from 2.21–2.58 Å. Hf4+ is bonded to five O2- atoms to form a mixture of distorted edge and corner-sharing HfO5 trigonal bipyramids. There are a spread of Hf–O bond distances ranging from 1.98–2.27 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Y3+ and two equivalent Hf4+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Y3+ and one Hf4+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Y3+ and one Hf4+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Hf4+ atoms.