Search NASA⌕ Search

SEARCH · Search NASA

Results for “RbHfMg6O7”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

3 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Materials Data on RbHfMg6O7 by Materials Project

RbMg6HfO7 crystallizes in the tetragonal P4mm space group. The structure is two-dimensional and consists of one RbMg6HfO7 sheet oriented in the (0, 0, 1) direction. Rb is bonded in a 4-coordinate geometry to four equivalent O atoms. All Rb–O bond lengths are 2.71 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share a cornercorner with one MgO6 octahedra and corners with four equivalent MgO5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.12 Å) and one longer (2.51 Å) Mg–O bond lengths. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four equivalent MgO6 octahedra, a cornercorner with one MgO5 square pyramid, and edges with four equivalent HfO5 square pyramids. The corner-sharing octahedral tilt angles are 6°. There are a spread of Mg–O bond distances ranging from 2.12–2.16 Å. In the third Mg site, Mg is bonded in a distorted T-shaped geometry to three O atoms. There are two shorter (2.14 Å) and one longer (2.42 Å) Mg–O bond lengths. In the fourth Mg site, Mg is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Mg–O bond distances ranging from 1.91–2.21 Å. Hf is bonded to five O atoms to form HfO5 square pyramids that share corners with four equivalent HfO5 square pyramids and edges with four equivalent MgO6 octahedra. There are one shorter (1.97 Å) and four longer (2.12 Å) Hf–O bond lengths. There are five inequivalent O sites. In the first O site, O is bonded to four equivalent Mg and one Hf atom to form distorted OHfMg4 trigonal bipyramids that share corners with four equivalent OHf2Mg3 square pyramids and corners with eight OHfMg4 trigonal bipyramids. In the second O site, O is bonded to five Mg atoms to form OMg5 square pyramids that share corners with four equivalent OMg5 square pyramids and edges with four equivalent OHf2Mg3 square pyramids. In the third O site, O is bonded in a 6-coordinate geometry to six Mg atoms. In the fourth O site, O is bonded to two equivalent Rb and three Mg atoms to form distorted ORb2Mg3 trigonal bipyramids that share corners with six OHfMg4 trigonal bipyramids and edges with four equivalent ORb2Mg3 trigonal bipyramids. In the fifth O site, O is bonded to three Mg and two equivalent Hf atoms to form distorted OHf2Mg3 square pyramids that share corners with four equivalent OHf2Mg3 square pyramids, corners with two equivalent OHfMg4 trigonal bipyramids, and edges with six OMg5 square pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbHfMg6O7 by Materials Project

RbMg6HfO7 crystallizes in the tetragonal P4mm space group. The structure is two-dimensional and consists of one RbMg6HfO7 sheet oriented in the (0, 0, 1) direction. Rb is bonded in a 4-coordinate geometry to four equivalent O atoms. All Rb–O bond lengths are 2.91 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded to five O atoms to form a mixture of distorted corner and edge-sharing MgO5 square pyramids. There are one shorter (1.97 Å) and four longer (2.11 Å) Mg–O bond lengths. In the second Mg site, Mg is bonded to five O atoms to form a mixture of distorted corner and edge-sharing MgO5 trigonal bipyramids. There are one shorter (2.05 Å) and four longer (2.12 Å) Mg–O bond lengths. In the third Mg site, Mg is bonded in a single-bond geometry to one O atom. The Mg–O bond length is 2.04 Å. In the fourth Mg site, Mg is bonded to five O atoms to form a mixture of distorted corner and edge-sharing MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 1.99–2.13 Å. Hf is bonded in a 5-coordinate geometry to five O atoms. There are one shorter (1.89 Å) and four longer (2.11 Å) Hf–O bond lengths. There are five inequivalent O sites. In the first O site, O is bonded to five Mg atoms to form distorted corner-sharing OMg5 trigonal bipyramids. In the second O site, O is bonded to four equivalent Rb and one Hf atom to form a mixture of distorted corner and edge-sharing ORb4Hf square pyramids. In the third O site, O is bonded in a 5-coordinate geometry to five Mg atoms. In the fourth O site, O is bonded in a 3-coordinate geometry to one Mg and two equivalent Hf atoms. In the fifth O site, O is bonded to five Mg atoms to form a mixture of distorted corner and edge-sharing OMg5 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbHfMg6O7 by Materials Project

RbMg6HfO7 crystallizes in the tetragonal P4mm space group. The structure is two-dimensional and consists of one RbMg6HfO7 sheet oriented in the (0, 0, 1) direction. Rb is bonded in a 4-coordinate geometry to four equivalent O atoms. All Rb–O bond lengths are 2.70 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded to five O atoms to form a mixture of edge and corner-sharing MgO5 square pyramids. There are four shorter (2.12 Å) and one longer (2.43 Å) Mg–O bond lengths. In the second Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with five MgO5 square pyramids, corners with four equivalent MgO5 trigonal bipyramids, and edges with four equivalent HfO6 octahedra. There are one shorter (2.01 Å) and four longer (2.15 Å) Mg–O bond lengths. In the third Mg site, Mg is bonded in a 2-coordinate geometry to three O atoms. There are two shorter (2.18 Å) and one longer (2.64 Å) Mg–O bond lengths. In the fourth Mg site, Mg is bonded to five O atoms to form distorted MgO5 trigonal bipyramids that share corners with two equivalent HfO6 octahedra, corners with two equivalent MgO5 square pyramids, corners with four equivalent MgO5 trigonal bipyramids, edges with two equivalent MgO5 square pyramids, and edges with four equivalent MgO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 71°. There are a spread of Mg–O bond distances ranging from 1.92–2.24 Å. Hf is bonded to six O atoms to form HfO6 octahedra that share corners with four equivalent HfO6 octahedra, corners with four equivalent MgO5 trigonal bipyramids, and edges with four equivalent MgO5 square pyramids. The corner-sharing octahedral tilt angles are 2°. There are a spread of Hf–O bond distances ranging from 2.03–2.15 Å. There are five inequivalent O sites. In the first O site, O is bonded to four equivalent Mg and one Hf atom to form distorted corner-sharing OHfMg4 trigonal bipyramids. In the second O site, O is bonded in a 5-coordinate geometry to four equivalent Mg and one Hf atom. In the third O site, O is bonded in a 6-coordinate geometry to six Mg atoms. In the fourth O site, O is bonded to two equivalent Rb and three Mg atoms to form a mixture of distorted edge and corner-sharing ORb2Mg3 trigonal bipyramids. In the fifth O site, O is bonded in a 4-coordinate geometry to three Mg and two equivalent Hf atoms.

36 MATERIALS SCIENCE↗