SEARCH · Search NASA
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.
HoFe2 is Cubic Laves structured and crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Ho is bonded in a 12-coordinate geometry to twelve equivalent Fe atoms. All Ho–Fe bond lengths are 3.00 Å. Fe is bonded to six equivalent Ho and six equivalent Fe atoms to form a mixture of corner, edge, and face-sharing FeHo6Fe6 cuboctahedra. All Fe–Fe bond lengths are 2.56 Å.
Ho6Fe23 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Ho is bonded in a 12-coordinate geometry to twelve Fe atoms. There are a spread of Ho–Fe bond distances ranging from 2.89–3.03 Å. There are four inequivalent Fe sites. In the first Fe site, Fe is bonded in a 10-coordinate geometry to three equivalent Ho and ten Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.52–2.91 Å. In the second Fe site, Fe is bonded in a body-centered cubic geometry to eight equivalent Fe atoms. In the third Fe site, Fe is bonded to four equivalent Ho and eight Fe atoms to form a mixture of face and corner-sharing FeHo4Fe8 cuboctahedra. All Fe–Fe bond lengths are 2.45 Å. In the fourth Fe site, Fe is bonded in a distorted q6 geometry to three equivalent Ho and nine Fe atoms. All Fe–Fe bond lengths are 2.53 Å.
HoFe3 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent Ho sites. In the first Ho site, Ho is bonded in a 6-coordinate geometry to eighteen Fe atoms. There are six shorter (2.94 Å) and twelve longer (3.22 Å) Ho–Fe bond lengths. In the second Ho site, Ho is bonded in a 12-coordinate geometry to twelve Fe atoms. There are a spread of Ho–Fe bond distances ranging from 2.94–3.05 Å. There are three inequivalent Fe sites. In the first Fe site, Fe is bonded to six equivalent Ho and six equivalent Fe atoms to form FeHo6Fe6 cuboctahedra that share corners with twelve equivalent FeHo5Fe7 cuboctahedra, edges with six equivalent FeHo6Fe6 cuboctahedra, and faces with eighteen equivalent FeHo5Fe7 cuboctahedra. All Fe–Fe bond lengths are 2.54 Å. In the second Fe site, Fe is bonded in a 12-coordinate geometry to three equivalent Ho and six equivalent Fe atoms. There are three shorter (2.45 Å) and three longer (2.47 Å) Fe–Fe bond lengths. In the third Fe site, Fe is bonded to five Ho and seven Fe atoms to form FeHo5Fe7 cuboctahedra that share corners with seventeen FeHo6Fe6 cuboctahedra, edges with eight equivalent FeHo5Fe7 cuboctahedra, and faces with fourteen FeHo6Fe6 cuboctahedra. There are two shorter (2.54 Å) and two longer (2.55 Å) Fe–Fe bond lengths.
Ho4Fe is Iron carbide-like structured and crystallizes in the cubic Fd-3m space group. The structure is zero-dimensional and consists of eight Ho4Fe clusters. Ho is bonded in a single-bond geometry to one Fe atom. The Ho–Fe bond length is 2.43 Å. Fe is bonded in a tetrahedral geometry to four equivalent Ho atoms.
Ho3Fe29 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Ho sites. In the first Ho site, Ho is bonded in a 12-coordinate geometry to twenty Fe atoms. There are a spread of Ho–Fe bond distances ranging from 2.97–3.20 Å. In the second Ho site, Ho is bonded in a 8-coordinate geometry to nineteen Fe atoms. There are a spread of Ho–Fe bond distances ranging from 2.98–3.27 Å. There are eleven inequivalent Fe sites. In the first Fe site, Fe is bonded to two equivalent Ho and ten Fe atoms to form FeHo2Fe10 cuboctahedra that share corners with eighteen FeHo2Fe10 cuboctahedra, edges with eight FeHo3Fe9 cuboctahedra, and faces with fourteen FeHo2Fe10 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.36–2.55 Å. In the second Fe site, Fe is bonded to two equivalent Ho and ten Fe atoms to form a mixture of distorted face, edge, and corner-sharing FeHo2Fe10 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.35–2.58 Å. In the third Fe site, Fe is bonded in a 2-coordinate geometry to one Ho and thirteen Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.37–2.83 Å. In the fourth Fe site, Fe is bonded in a 12-coordinate geometry to one Ho and thirteen Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.54–2.90 Å. In the fifth Fe site, Fe is bonded to two Ho and ten Fe atoms to form a mixture of distorted face, edge, and corner-sharing FeHo2Fe10 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.38–2.65 Å. In the sixth Fe site, Fe is bonded in a 12-coordinate geometry to two equivalent Ho and ten Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.29–2.63 Å. In the seventh Fe site, Fe is bonded in a 2-coordinate geometry to one Ho and thirteen Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.38–2.59 Å. In the eighth Fe site, Fe is bonded to two Ho and ten Fe atoms to form a mixture of distorted face, edge, and corner-sharing FeHo2Fe10 cuboctahedra. Both Fe–Fe bond lengths are 2.39 Å. In the ninth Fe site, Fe is bonded to two Ho and ten Fe atoms to form a mixture of face, edge, and corner-sharing FeHo2Fe10 cuboctahedra. Both Fe–Fe bond lengths are 2.42 Å. In the tenth Fe site, Fe is bonded to three Ho and nine Fe atoms to form a mixture of face, edge, and corner-sharing FeHo3Fe9 cuboctahedra. Both Fe–Fe bond lengths are 2.45 Å. In the eleventh Fe site, Fe is bonded to three equivalent Ho and nine Fe atoms to form a mixture of face, edge, and corner-sharing FeHo3Fe9 cuboctahedra. The Fe–Fe bond length is 2.45 Å.
Ho2Fe17 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Ho sites. In the first Ho site, Ho is bonded in a 12-coordinate geometry to eighteen Fe atoms. There are a spread of Ho–Fe bond distances ranging from 2.97–3.28 Å. In the second Ho site, Ho is bonded in a 8-coordinate geometry to twenty Fe atoms. There are a spread of Ho–Fe bond distances ranging from 2.94–3.20 Å. There are four inequivalent Fe sites. In the first Fe site, Fe is bonded in a 2-coordinate geometry to one Ho and thirteen Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.37–2.78 Å. In the second Fe site, Fe is bonded to two equivalent Ho and ten Fe atoms to form FeHo2Fe10 cuboctahedra that share corners with fourteen FeHo2Fe10 cuboctahedra, edges with six equivalent FeHo3Fe9 cuboctahedra, and faces with ten FeHo2Fe10 cuboctahedra. There are four shorter (2.45 Å) and four longer (2.46 Å) Fe–Fe bond lengths. In the third Fe site, Fe is bonded in a 12-coordinate geometry to two Ho and ten Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.46–2.59 Å. In the fourth Fe site, Fe is bonded to three Ho and nine Fe atoms to form a mixture of distorted face, edge, and corner-sharing FeHo3Fe9 cuboctahedra. Both Fe–Fe bond lengths are 2.45 Å.