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At least 307 records · Page 17
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on SbPH4(O2F3)2 by Materials Project

P(HO)4SbF6 crystallizes in the monoclinic C2/c space group. The structure is zero-dimensional and consists of four tetrahydroxyphosphanium molecules and four SbF6 clusters. In each SbF6 cluster, Sb5+ is bonded in an octahedral geometry to six F1- atoms. There are a spread of Sb–F bond distances ranging from 1.91–1.94 Å. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Sb5+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one Sb5+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to one Sb5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(H9O5)2 by Materials Project

Ba(HO)10(H2)4 crystallizes in the monoclinic P2_1/c space group. The structure is one-dimensional and consists of sixteen hydrogen molecules and two Ba(HO)10 ribbons oriented in the (0, 1, 0) direction. In each Ba(HO)10 ribbon, Ba2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ba–O bond distances ranging from 2.49–2.97 Å. There are ten inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a distorted single-bond geometry to two O2- atoms. There is one shorter (1.02 Å) and one longer (1.59 Å) H–O bond length. In the third H1+ site, H1+ is bonded in a distorted single-bond geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.66 Å) H–O bond length. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.01 Å. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to two H1+ atoms. In the second O2- site, O2- is bonded in a single-bond geometry to one Ba2+, one H1+, and one O2- atom. The O–O bond length is 1.49 Å. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+ and one O2- atom. The O–O bond length is 1.30 Å. In the fourth O2- site, O2- is bonded in a single-bond geometry to one Ba2+, one H1+, and one O2- atom. The O–O bond length is 1.42 Å. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one O2- atom. In the sixth O2- site, O2- is bonded in a water-like geometry to one Ba2+ and two H1+ atoms. In the seventh O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three H1+ atoms. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+ and one O2- atom. In the ninth O2- site, O2- is bonded in a water-like geometry to one Ba2+ and two H1+ atoms. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+, one H1+, and one O2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho7(TeAu)2 by Materials Project

Ho7(AuTe)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are eight inequivalent Ho sites. In the first Ho site, Ho is bonded in a 5-coordinate geometry to two equivalent Au and three Te atoms. Both Ho–Au bond lengths are 2.95 Å. There are one shorter (3.07 Å) and two longer (3.19 Å) Ho–Te bond lengths. In the second Ho site, Ho is bonded in a 4-coordinate geometry to two equivalent Au and two equivalent Te atoms. Both Ho–Au bond lengths are 3.00 Å. Both Ho–Te bond lengths are 3.23 Å. In the third Ho site, Ho is bonded in a 2-coordinate geometry to three Au and one Te atom. There are two shorter (2.92 Å) and one longer (3.50 Å) Ho–Au bond lengths. The Ho–Te bond length is 3.12 Å. In the fourth Ho site, Ho is bonded in a 4-coordinate geometry to three equivalent Au and two equivalent Te atoms. There are two shorter (2.97 Å) and one longer (3.77 Å) Ho–Au bond lengths. Both Ho–Te bond lengths are 3.18 Å. In the fifth Ho site, Ho is bonded in a 4-coordinate geometry to two equivalent Au and two equivalent Te atoms. Both Ho–Au bond lengths are 3.00 Å. Both Ho–Te bond lengths are 3.19 Å. In the sixth Ho site, Ho is bonded in a 5-coordinate geometry to two equivalent Au and three Te atoms. Both Ho–Au bond lengths are 2.94 Å. There are one shorter (3.09 Å) and two longer (3.25 Å) Ho–Te bond lengths. In the seventh Ho site, Ho is bonded in a square co-planar geometry to two equivalent Au and two equivalent Te atoms. Both Ho–Au bond lengths are 3.08 Å. Both Ho–Te bond lengths are 3.22 Å. In the eighth Ho site, Ho is bonded in a square co-planar geometry to two equivalent Au and two equivalent Te atoms. Both Ho–Au bond lengths are 3.22 Å. Both Ho–Te bond lengths are 3.08 Å. There are two inequivalent Au sites. In the first Au site, Au is bonded in a 9-coordinate geometry to nine Ho atoms. In the second Au site, Au is bonded in a 7-coordinate geometry to seven Ho atoms. There are two inequivalent Te sites. In the first Te site, Te is bonded in a 8-coordinate geometry to eight Ho atoms. In the second Te site, Te is bonded in a 7-coordinate geometry to seven Ho atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaB(H4O3)2 by Materials Project

NaB(HO)6H2 crystallizes in the triclinic P-1 space group. The structure is one-dimensional and consists of two hydrogen molecules and one NaB(HO)6 ribbon oriented in the (1, 0, 0) direction. In the NaB(HO)6 ribbon, Na1+ is bonded to six O2- atoms to form edge-sharing NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.38–2.58 Å. B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.33–1.42 Å. There are six inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. In the fourth H1+ site, H1+ is bonded in a distorted single-bond geometry to two O2- atoms. There is one shorter (1.02 Å) and one longer (1.63 Å) H–O bond length. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Na1+, one B3+, and one H1+ atom. In the second O2- site, O2- is bonded in a water-like geometry to one B3+ and one H1+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to one Na1+ and one H1+ atom. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to one Na1+, one B3+, and one H1+ atom. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to two equivalent Na1+ and two H1+ atoms. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to one Na1+ and one H1+ atom.

36 MATERIALS SCIENCE↗
NASA NTRS2000

A High Energy 2-microns Laser for Multiple Lidar Applications

Solid-state 2-microns laser has been receiving considerable interest because of its eye-safe property and efficient diode pump operation, It has potential for multiple lidar applications to detect water vapor. carbon dioxide and winds. In this paper, we describe a 2-microns double pulsed Ho:Tm:YLF laser and end-pumped amplifier system. A comprehensive theoretical model has been developed to aid the design and optimization of the laser performance. In a single Q-switched pulse operation the residual energy stored in the Tm atoms will be wasted. However, in a double pulses operation mode, the residual energy stored in the Tm atoms will repopulate the Ho atoms that were depleted by the extraction of the first Q-switched pulse. Thus. the Tin sensitized Ho:YLF laser provides a unique advantage in applications that require double pulse operation, such as Differential Absorption Lidar (DIAL). A total output energy of 146 mJ per pulse pair under Q-switch operation is achieved with as high as 4.8% optical to optical efficiency. Compared to a single pulse laser, 70% higher laser efficiency is realized. To obtain high energy while maintaining the high beam quality, a master-oscillator-power-amplifier 2-microns system is designed. We developed an end-pumped Ho:Tm:YLF disk amplifier. This amplifier uses two diode arrays as pump source. A non-imaging lens duct is used to couple the radiation from the laser diode arrays to the laser disk. Preliminary result shows that the efficiency of this laser can be as high as 3%, a factor of three increases over side-pump configuration. This high energy, highly efficient and high beam quality laser is a promising candidate for use in an efficient, multiple lidar applications.

Yu, Jirong↗
DOE OSTI2020

Materials Data on Mg4Al2H12CO18 by Materials Project

(Mg2Al(HO)6)4(CO3)2(O2)3 crystallizes in the trigonal P31m space group. The structure is two-dimensional and consists of one carbonic acid molecule; three water molecules; and two Mg2Al(HO)6 sheets oriented in the (0, 0, 1) direction. In each Mg2Al(HO)6 sheet, Mg is bonded to six O atoms to form MgO6 octahedra that share edges with three equivalent MgO6 octahedra and edges with three equivalent AlO6 octahedra. There are three shorter (2.09 Å) and three longer (2.10 Å) Mg–O bond lengths. Al is bonded to six O atoms to form AlO6 octahedra that share edges with six equivalent MgO6 octahedra. All Al–O bond lengths are 1.93 Å. There are two inequivalent H sites. In the first H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.99 Å. In the second H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. There are two inequivalent O sites. In the first O site, O is bonded in a 1-coordinate geometry to two equivalent Mg, one Al, and one H atom. In the second O site, O is bonded in a 1-coordinate geometry to two equivalent Mg, one Al, and one H atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho6N8O33 by Materials Project

Ho6N4O21(NO3)4 crystallizes in the triclinic P-1 space group. The structure is one-dimensional and consists of four nitric acid molecules and one Ho6N4O21 ribbon oriented in the (1, 0, 0) direction. In the Ho6N4O21 ribbon, there are three inequivalent Ho sites. In the first Ho site, Ho is bonded in a 2-coordinate geometry to three O atoms. There are a spread of Ho–O bond distances ranging from 1.90–2.37 Å. In the second Ho site, Ho is bonded in a 4-coordinate geometry to four O atoms. There are a spread of Ho–O bond distances ranging from 1.88–2.34 Å. In the third Ho site, Ho is bonded in a distorted single-bond geometry to three O atoms. There are a spread of Ho–O bond distances ranging from 1.63–2.64 Å. There are two inequivalent N sites. In the first N site, N is bonded in a trigonal planar geometry to three O atoms. There are a spread of N–O bond distances ranging from 1.18–1.43 Å. In the second N site, N is bonded in a distorted trigonal planar geometry to three O atoms. There are a spread of N–O bond distances ranging from 1.28–1.80 Å. There are eleven inequivalent O sites. In the first O site, O is bonded in a water-like geometry to one Ho and one N atom. In the second O site, O is bonded in a distorted linear geometry to two equivalent Ho atoms. In the third O site, O is bonded in a water-like geometry to one Ho and one N atom. In the fourth O site, O is bonded in a 1-coordinate geometry to one Ho atom. In the fifth O site, O is bonded in a distorted bent 150 degrees geometry to one Ho and one N atom. In the sixth O site, O is bonded in a single-bond geometry to one N atom. In the seventh O site, O is bonded in a distorted bent 120 degrees geometry to two Ho atoms. In the eighth O site, O is bonded in a bent 120 degrees geometry to two Ho atoms. In the ninth O site, O is bonded in a single-bond geometry to one N atom. In the tenth O site, O is bonded in a single-bond geometry to one N atom. In the eleventh O site, O is bonded in a distorted single-bond geometry to one Ho atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoAl by Materials Project

HoAl crystallizes in the orthorhombic Pbcm space group. The structure is three-dimensional. there are two inequivalent Ho sites. In the first Ho site, Ho is bonded in a 2-coordinate geometry to eight Al atoms. There are a spread of Ho–Al bond distances ranging from 3.05–3.38 Å. In the second Ho site, Ho is bonded in a 6-coordinate geometry to eight Al atoms. There are a spread of Ho–Al bond distances ranging from 3.05–3.53 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded to eight Ho and four Al atoms to form a mixture of distorted corner, edge, and face-sharing AlHo8Al4 cuboctahedra. There are two shorter (2.72 Å) and two longer (2.81 Å) Al–Al bond lengths. In the second Al site, Al is bonded in a 10-coordinate geometry to eight Ho and two equivalent Al atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho11Sn10 by Materials Project

Ho11Sn10 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are four inequivalent Ho sites. In the first Ho site, Ho is bonded to seven Sn atoms to form a mixture of distorted edge, face, and corner-sharing HoSn7 pentagonal bipyramids. There are a spread of Ho–Sn bond distances ranging from 3.06–3.45 Å. In the second Ho site, Ho is bonded in a 7-coordinate geometry to seven Sn atoms. There are a spread of Ho–Sn bond distances ranging from 2.93–3.57 Å. In the third Ho site, Ho is bonded in a 9-coordinate geometry to nine Sn atoms. There are a spread of Ho–Sn bond distances ranging from 3.40–3.80 Å. In the fourth Ho site, Ho is bonded in a 7-coordinate geometry to seven Sn atoms. There are a spread of Ho–Sn bond distances ranging from 3.06–3.27 Å. There are five inequivalent Sn sites. In the first Sn site, Sn is bonded in a 8-coordinate geometry to eight Ho atoms. In the second Sn site, Sn is bonded in a 9-coordinate geometry to nine Ho atoms. In the third Sn site, Sn is bonded in a 11-coordinate geometry to seven Ho and four Sn atoms. There are two shorter (3.00 Å) and two longer (3.25 Å) Sn–Sn bond lengths. In the fourth Sn site, Sn is bonded in a 8-coordinate geometry to eight Ho atoms. In the fifth Sn site, Sn is bonded in a 2-coordinate geometry to eight Ho and two Sn atoms. The Sn–Sn bond length is 2.90 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoCd6 by Materials Project

HoCd6 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. there are three inequivalent Ho sites. In the first Ho site, Ho is bonded in a 11-coordinate geometry to seventeen Cd atoms. There are a spread of Ho–Cd bond distances ranging from 3.29–3.66 Å. In the second Ho site, Ho is bonded in a 2-coordinate geometry to sixteen Cd atoms. There are a spread of Ho–Cd bond distances ranging from 3.28–3.67 Å. In the third Ho site, Ho is bonded in a 3-coordinate geometry to sixteen Cd atoms. There are a spread of Ho–Cd bond distances ranging from 3.27–3.63 Å. There are seventeen inequivalent Cd sites. In the first Cd site, Cd is bonded in a 10-coordinate geometry to three Ho and seven Cd atoms. There are a spread of Cd–Cd bond distances ranging from 2.93–3.13 Å. In the second Cd site, Cd is bonded to three Ho and nine Cd atoms to form a mixture of face and edge-sharing CdHo3Cd9 cuboctahedra. There are a spread of Cd–Cd bond distances ranging from 2.83–3.22 Å. In the third Cd site, Cd is bonded in a 10-coordinate geometry to three Ho and seven Cd atoms. There are a spread of Cd–Cd bond distances ranging from 2.87–3.11 Å. In the fourth Cd site, Cd is bonded to three Ho and nine Cd atoms to form a mixture of face and edge-sharing CdHo3Cd9 cuboctahedra. There are a spread of Cd–Cd bond distances ranging from 2.85–3.21 Å. In the fifth Cd site, Cd is bonded to two equivalent Ho and ten Cd atoms to form distorted CdHo2Cd10 cuboctahedra that share corners with two equivalent CdHo2Cd10 cuboctahedra, an edgeedge with one CdHo2Cd10 cuboctahedra, and faces with six CdHo3Cd9 cuboctahedra. There are two shorter (2.89 Å) and two longer (3.36 Å) Cd–Cd bond lengths. In the sixth Cd site, Cd is bonded in a 12-coordinate geometry to two equivalent Ho and ten Cd atoms. There are a spread of Cd–Cd bond distances ranging from 2.82–3.44 Å. In the seventh Cd site, Cd is bonded to two equivalent Ho and ten Cd atoms to form distorted CdHo2Cd10 cuboctahedra that share corners with two equivalent CdHo2Cd10 cuboctahedra, an edgeedge with one CdHo2Cd10 cuboctahedra, and faces with six CdHo3Cd9 cuboctahedra. Both Cd–Cd bond lengths are 3.34 Å. In the eighth Cd site, Cd is bonded in a 10-coordinate geometry to three Ho and seven Cd atoms. There are a spread of Cd–Cd bond distances ranging from 2.99–3.06 Å. In the ninth Cd site, Cd is bonded in a 10-coordinate geometry to three Ho and seven Cd atoms. There are a spread of Cd–Cd bond distances ranging from 2.97–3.10 Å. In the tenth Cd site, Cd is bonded in a 8-coordinate geometry to one Ho and seven Cd atoms. There are a spread of Cd–Cd bond distances ranging from 2.69–3.07 Å. In the eleventh Cd site, Cd is bonded in a 11-coordinate geometry to three Ho and eight Cd atoms. There are one shorter (2.97 Å) and one longer (3.00 Å) Cd–Cd bond lengths. In the twelfth Cd site, Cd is bonded in a 10-coordinate geometry to three Ho and seven Cd atoms. There are one shorter (2.84 Å) and one longer (2.96 Å) Cd–Cd bond lengths. In the thirteenth Cd site, Cd is bonded in a 11-coordinate geometry to two equivalent Ho and nine Cd atoms. The Cd–Cd bond length is 2.96 Å. In the fourteenth Cd site, Cd is bonded in a 11-coordinate geometry to two equivalent Ho and nine Cd atoms. There are a spread of Cd–Cd bond distances ranging from 3.04–3.22 Å. In the fifteenth Cd site, Cd is bonded in a distorted q6 geometry to three Ho and six Cd atoms. The Cd–Cd bond length is 2.90 Å. In the sixteenth Cd site, Cd is bonded in a 11-coordinate geometry to two equivalent Ho and nine Cd atoms. The Cd–Cd bond length is 3.02 Å. In the seventeenth Cd site, Cd is bonded to three Ho and nine Cd atoms to form a mixture of face and edge-sharing CdHo3Cd9 cuboctahedra. The Cd–Cd bond length is 3.11 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho3Fe29 by Materials Project

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.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Novel complex ceramic oxides, Ln 2 TiO 5 (Ln = La, Sm, Gd, Tb, Dy, Ho, Er, and Yb), for polyphase nuclear waste‐forms

Abstract As part of a broader study of ceramic nuclear waste‐forms, four different lanthanide titanates were fabricated; La 0.1 Sm 0.1 Gd 0.1 Tb 0.1 Dy 0.3 Ho 0.1 Er 0.2 YbTiO 5 , Sm 0.3 Gd 0.3 Dy 0.3 Yb 1.1 TiO 5 , Sm 0.1 Gd 0.4 Dy 0.4 Yb 1.1 TiO 5 , and Sm 0.2 Gd 0.2 Dy 0.2 Yb 1.4 TiO 5 . The aim was to produce single‐phase novel materials with cubic symmetry, capable of incorporating a wide variety of cations and with acceptable radiation tolerance. The chemistry flexibility and radiation tolerance are some of the major desirable properties for nuclear waste‐form materials. By using multiple lanthanides the average lanthanide radius can be controlled and consequently the structure, along with properties such as radiation tolerance. The radiation tolerance was assessed using in situ 1 MeV krypton irradiation and transmission electron microscopy characterization. Those materials for which cubic symmetry was achieved displayed better radiation tolerance; a greater critical fluence of ions ( F c ) was required for the crystalline to amorphous transition, and a lower temperature was required to maintain crystallinity ( T c ) during irradiation.

Aughterson, Robert D.↗
DOE OSTI2020

Materials Data on Ho3Pt by Materials Project

Ho3Pt is Cementite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Ho sites. In the first Ho site, Ho is bonded in a 2-coordinate geometry to three equivalent Pt atoms. There are a spread of Ho–Pt bond distances ranging from 2.84–3.35 Å. In the second Ho site, Ho is bonded in a distorted bent 150 degrees geometry to two equivalent Pt atoms. There are one shorter (2.80 Å) and one longer (2.91 Å) Ho–Pt bond lengths. Pt is bonded in a 6-coordinate geometry to eight Ho atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho3Ir by Materials Project

Ho3Ir is Cementite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Ho sites. In the first Ho site, Ho is bonded in a 2-coordinate geometry to three equivalent Ir atoms. There are a spread of Ho–Ir bond distances ranging from 2.86–3.23 Å. In the second Ho site, Ho is bonded in a distorted bent 150 degrees geometry to two equivalent Ir atoms. There are one shorter (2.77 Å) and one longer (2.85 Å) Ho–Ir bond lengths. Ir is bonded in a 6-coordinate geometry to eight Ho atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Preliminary Evidence of Gas-Phase Water Splitting on Holmium Nitrogen Oxide Clusters

Preliminary Evidence of Gas-Phase Water Splitting on Holmium Nitrogen Oxide Clusters Christopher A. Zarzana1, Makayla R. Baxter , Introduction: Molecular hydrogen is a potential energy carrier that could be used to help implement a clean energy economy if it is generated from splitting of water. Improvements in the efficiencies of water-splitting electrolyzers relies on development of novel materials with enhanced performance. However, research in this area is slowed due to underdeveloped understanding of the mechanisms of device performance due to challenges interrogating the fundamental chemical reactions at play in bulk materials. Studies of the intrinsic reactivity of clusters that are representative of the reactive sites of these materials can increase understanding of the fundamental reaction mechanisms involved in hydrogen production, allowing for more efficient development of new water-splitting materials. Methods: Holmium tetranitrato ([Ho(NO3)4]-) clusters were generated in gas-phase using the electrospray ionization source of a Bruker (Billerica, MA, USA) micrOTOF-Q II quadrupole time-of-flight mass spectrometer. Spray solutions consisted of aqueous holmium (Ho) nitrate solutions (at nominally 3 mM) diluted to 30 µM in acetonitrile. The holmium (Ho) tetranitrato clusters were isolated using the quadrupole and were subsequently activated and allowed to react with background water in the collision cell. High resolution, high mass accuracy spectra were recorded using the time-of-flight. Mass accuracy was ensured using external calibration with Agilent (Santa Clara, CA, USA) ESI-L Low Concentration tuning mix. Preliminary data: Collisional activation of the holmium tetranitrato complexes ([Ln(NO3)4]-) resulted in an expected series of ions resulting from the loss of ·NO and ·NO2. This included an ion at m/z = 382.885 assigned as [HoO2(NO3)3]- (theoretical m/z=382.884, error=-1.2 ppm), resulting from loss of ·NO, and an ion at m/z=366.890 assigned as [HoO(NO3)3]- (theorical m/z=366.889, error=-1.8 ppm), resulting from loss of ·NO2. Additional ions were detected that would result from more complicated losses from [Ho(NO3)4]-, including ions at m/z=320.898 assigned as [HoO2(NO3)2]- (theoretical m/z=320.896, error=-4.9 ppm), at m/z=304.904 assigned as [HoO(NO3)2]- (theoretical m/z=304.901, error=-8.1 ppm, very low signal), and at m/z=288.908 assigned as [Ho(NO3)2]- (theoretical m/z=288.907, error=-3.4 ppm). This ion series would arise from loss of some combination of ·NO, ·NO2, and ·NO3, although it is not known whether these losses occur sequentially (e.g. loss of ·NO and ·NO3 to yield [HoO2(NO3)2]-) or as a single species (e.g. direct loss of N2O4). These ions were accompanied by a complementary series representing addition of a single water molecule. This included an ion at m/z=338.908 assigned as [HoO2(NO3)2H2O]- (theoretical m/z=338.907, error=-4.1 ppm), an ion at m/z=322.912 assigned as [HoO(NO3)2H2O]- (theoretical m/z=322.912, error=1.2 ppm), and an ion at m/z=306.918 assigned as [Ho(NO3)2H2O]-, (theoretical m/z=306.918, error=-3.7 ppm). An additional hydrated ion was observed at m/z=276.921 assigned as [HoO2(NO3) H2O]- (theoretical m/z=276.919, error=-7.3 ppm), although corresponding dehydrated ion was not observed. An additional ion was observed at m/z=367.898 that has been assigned as [Ho(NO3)3OH]- (theoretical m/z=367.897, error=-2.5 ppm). It is hypothesized that this ion arises from addition of water to [Ho(NO3)3]- followed by elimination of a hydrogen radical. Neither [Ho(NO3)3]- nor [Ho(NO3)3H2O]- were detected, suggesting that, if the hypothesis is correct, addition of water to [Ho(NO3)3]- and its subsequent splitting is rapid. Elimination of HNO3 from [Ho(NO3)4H2O]- could also yield [Ho(NO3)3OH]-; however, no [Ho(NO3)4H2O]- ions were observed. Novelty: Potential evidence of water splitting on gas-phase lanthanide clusters offers a way to study the intrinsic reactivity of hydrogen-generation materials.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS2000

High Energy Directly Pumped Ho:YLF Laser

The most commonly used crystal architecture to produce 2 micrometer laser is co-doping Ho and Tm into a single host crystal. In this method, the stored energy transfer from the Tm (3)F4 to the Ho (5)I7 manifold is not fast enough to warrant high efficiency for short pulse applications. By separating the Ho and the Tm ions and doping the Tm in YALO3 and the Ho in YLF, we were able to directly pump the Ho (5)I7 manifold with 1.94 micrometers. The Ho:YLF laser has produced 33 mJ at 2.062 micrometers with a quantum efficiency of 0.88. The performance of each laser will be presented.

Petros, Mulugeta↗
DOE OSTI2025

Heterobimetallic multi-site concerted proton electron transfer (MS-CPET) promotes coordination-induced O–H bond weakening

Coordination-induced bond weakening of X–H bonds (X = O, N, C) has been observed in a number of low-valent transition metal compounds. However, the impact of an appended electron reservoir on the bond dissociation free energy of the O–H bond (BDFE O–H ) of a substrate bound to a d 0 metal is poorly understood. To gain insight into the ability of separated deprotonation and oxidation sites to decrease the BDFE O–H during proton-coupled electron transfer (PCET) reactions, a bimetallic system in which the sites of proton and electron loss are two distinct metal sites is described. Herein, the interconversion of tris(phosphinoamide) Zr/Co complexes HO–Zr(MesNP i Pr 2 ) 3 CoCN t Bu and O$≡$Zr(MesNP i Pr 2 ) 3 CoCN t Bu via hydrogen atom addition/abstraction was studied. Since the Zr center remains in the d 0 Zr IV state throughout these transformations, the electron transfer process is mediated by the appended redox-active Co 0/I center. A series of open-circuit potential (OCP) measurements on the HO–Zr(MesNP i Pr 2 ) 3 CoCN t Bu and O$≡$Zr(MesNP i Pr 2 ) 3 CoCN t Bu complexes was performed, from which the BDFE O–H was found to be 64 ± 1 kcal mol −1 . The BDFE O–H value was further verified through a series of stoichiometric H atom transfer reactions, stoichiometric protonation/deprotonation reactions, and computational studies.

Chemistry↗