DOE OSTI2020
ErGdO3 is Spinel-like structured and crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are five inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded to six O2- atoms to form distorted ErO6 octahedra that share corners with three ErO6 octahedra, corners with three GdO6 octahedra, an edgeedge with one ErO6 octahedra, and edges with five GdO6 octahedra. The corner-sharing octahedra tilt angles range from 52–59°. There are a spread of Er–O bond distances ranging from 2.24–2.35 Å. In the second Er3+ site, Er3+ is bonded to six O2- atoms to form distorted ErO6 octahedra that share a cornercorner with one ErO6 octahedra, corners with five GdO6 octahedra, edges with three ErO6 octahedra, and edges with three GdO6 octahedra. The corner-sharing octahedra tilt angles range from 53–56°. There are a spread of Er–O bond distances ranging from 2.24–2.35 Å. In the third Er3+ site, Er3+ is bonded to six O2- atoms to form distorted ErO6 octahedra that share corners with two equivalent ErO6 octahedra, corners with four GdO6 octahedra, edges with two equivalent GdO6 octahedra, and edges with four ErO6 octahedra. The corner-sharing octahedra tilt angles range from 53–57°. There are four shorter (2.25 Å) and two longer (2.35 Å) Er–O bond lengths. In the fourth Er3+ site, Er3+ is bonded to six O2- atoms to form distorted ErO6 octahedra that share corners with two equivalent GdO6 octahedra, corners with four ErO6 octahedra, edges with two equivalent ErO6 octahedra, and edges with four GdO6 octahedra. The corner-sharing octahedra tilt angles range from 53–57°. There are a spread of Er–O bond distances ranging from 2.25–2.33 Å. In the fifth Er3+ site, Er3+ is bonded to six O2- atoms to form distorted ErO6 octahedra that share corners with three ErO6 octahedra, corners with three GdO6 octahedra, edges with three ErO6 octahedra, and edges with three GdO6 octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There are a spread of Er–O bond distances ranging from 2.23–2.35 Å. There are five inequivalent Gd3+ sites. In the first Gd3+ site, Gd3+ is bonded to six O2- atoms to form GdO6 octahedra that share corners with two GdO6 octahedra, corners with four ErO6 octahedra, edges with two GdO6 octahedra, and edges with four ErO6 octahedra. The corner-sharing octahedra tilt angles range from 56–58°. There are a spread of Gd–O bond distances ranging from 2.32–2.34 Å. In the second Gd3+ site, Gd3+ is bonded to six O2- atoms to form distorted GdO6 octahedra that share corners with three ErO6 octahedra, corners with three GdO6 octahedra, edges with three ErO6 octahedra, and edges with three GdO6 octahedra. The corner-sharing octahedra tilt angles range from 54–58°. There are a spread of Gd–O bond distances ranging from 2.27–2.39 Å. In the third Gd3+ site, Gd3+ is bonded to six O2- atoms to form distorted GdO6 octahedra that share corners with two equivalent ErO6 octahedra, corners with four GdO6 octahedra, edges with two equivalent GdO6 octahedra, and edges with four ErO6 octahedra. The corner-sharing octahedra tilt angles range from 54–58°. There are four shorter (2.29 Å) and two longer (2.40 Å) Gd–O bond lengths. In the fourth Gd3+ site, Gd3+ is bonded to six O2- atoms to form distorted GdO6 octahedra that share corners with two equivalent GdO6 octahedra, corners with four ErO6 octahedra, edges with two equivalent ErO6 octahedra, and edges with four GdO6 octahedra. The corner-sharing octahedra tilt angles range from 54–58°. There are a spread of Gd–O bond distances ranging from 2.29–2.38 Å. In the fifth Gd3+ site, Gd3+ is bonded to six O2- atoms to form GdO6 octahedra that share corners with two GdO6 octahedra, corners with four ErO6 octahedra, edges with two GdO6 octahedra, and edges with four ErO6 octahedra. The corner-sharing octahedra tilt angles range from 54–59°. There are a spread of Gd–O bond distances ranging from 2.32–2.34 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded to one Er3+ and three Gd3+ atoms to form a mixture of distorted edge and corner-sharing OGd3Er trigonal pyramids. In the second O2- site, O2- is bonded to three Er3+ and one Gd3+ atom to form distorted OGdEr3 trigonal pyramids that share a cornercorner with one OGd3Er tetrahedra, corners with eleven OGd3Er trigonal pyramids, and edges with four OGd2Er2 trigonal pyramids. In the third O2- site, O2- is bonded to two Er3+ and two Gd3+ atoms to form distorted OGd2Er2 trigonal pyramids that share corners with two equivalent OGd3Er tetrahedra, corners with ten OGd2Er2 trigonal pyramids, and edges with four OGd3Er trigonal pyramids. In the fourth O2- site, O2- is bonded to two Er3+ and two Gd3+ atoms to form a mixture of distorted edge and corner-sharing OGd2Er2 trigonal pyramids. In the fifth O2- site, O2- is bonded to one Er3+ and three Gd3+ atoms to form a mixture of distorted edge and corner-sharing OGd3Er tetrahedra. In the sixth O2- site, O2- is bonded to two Er3+ and two Gd3+ atoms to form a mixture of distorted edge and corner-sharing OGd2Er2 trigonal pyramids. In the seventh O2- site, O2- is bonded to one Er3+ and three Gd3+ atoms to form a mixture of distorted edge and corner-sharing OGd3Er trigonal pyramids. In the eighth O2- site, O2- is bonded to two Er3+ and two Gd3+ atoms to form distorted OGd2Er2 trigonal pyramids that share corners with twelve OGd3Er trigonal pyramids, edges with two equivalent OGd3Er tetrahedra, and edges with two OGd2Er2 trigonal pyramids. In the ninth O2- site, O2- is bonded to three Er3+ and one Gd3+ atom to form distorted OGdEr3 trigonal pyramids that share a cornercorner with one OGd3Er tetrahedra, corners with eleven OGd3Er trigonal pyramids, and edges with four OGd2Er2 trigonal pyramids. In the tenth O2- site, O2- is bonded to two Er3+ and two Gd3+ atoms to form distorted OGd2Er2 trigonal pyramids that share corners with two equivalent OGd3Er tetrahedra, corners with ten OGd2Er2 trigonal pyramids, and edges with four OGd3Er trigonal pyramids. In the eleventh O2- site, O2- is bonded to two Er3+ and two Gd3+ atoms to form distorted OGd2Er2 trigonal pyramids that share corners with two equivalent OGd3Er tetrahedra, corners with ten OGd2Er2 trigonal pyramids, and edges with four OGd2Er2 trigonal pyramids. In the twelfth O2- site, O2- is bonded to three Er3+ and one Gd3+ atom to form distorted OGdEr3 trigonal pyramids that share a cornercorner with one OGd3Er tetrahedra, corners with eleven OGd3Er trigonal pyramids, and edges with four OGd2Er2 trigonal pyramids.