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At least 865 records · Page 48
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Ho3(SbPd2)4 by Materials Project

Ho3(Pd2Sb)4 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Ho is bonded in a 1-coordinate geometry to eight Pd and five Sb atoms. There are four shorter (3.04 Å) and four longer (3.22 Å) Ho–Pd bond lengths. There are one shorter (2.98 Å) and four longer (3.33 Å) Ho–Sb bond lengths. There are two inequivalent Pd sites. In the first Pd site, Pd is bonded in a 6-coordinate geometry to three equivalent Ho and three equivalent Sb atoms. All Pd–Sb bond lengths are 2.71 Å. In the second Pd site, Pd is bonded in a 7-coordinate geometry to three equivalent Ho and four Sb atoms. There are one shorter (2.73 Å) and three longer (2.92 Å) Pd–Sb bond lengths. There are three inequivalent Sb sites. In the first Sb site, Sb is bonded in a body-centered cubic geometry to eight equivalent Pd atoms. In the second Sb site, Sb is bonded to four equivalent Ho and eight Pd atoms to form SbHo4Pd8 cuboctahedra that share corners with four equivalent SbHo4Pd8 cuboctahedra, edges with two equivalent SbHo6 octahedra, and faces with eight equivalent SbHo4Pd8 cuboctahedra. In the third Sb site, Sb is bonded to six equivalent Ho atoms to form edge-sharing SbHo6 octahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoNiGe3 by Materials Project

HoNiGe3 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. Ho is bonded in a 4-coordinate geometry to four equivalent Ni and ten Ge atoms. All Ho–Ni bond lengths are 3.16 Å. There are a spread of Ho–Ge bond distances ranging from 3.08–3.20 Å. Ni is bonded in a 9-coordinate geometry to four equivalent Ho and five Ge atoms. There are a spread of Ni–Ge bond distances ranging from 2.29–2.35 Å. There are three inequivalent Ge sites. In the first Ge site, Ge is bonded in a 1-coordinate geometry to six equivalent Ho, one Ni, and two equivalent Ge atoms. Both Ge–Ge bond lengths are 2.50 Å. In the second Ge site, Ge is bonded in a 2-coordinate geometry to two equivalent Ho, two equivalent Ni, and five Ge atoms. There are one shorter (2.48 Å) and four longer (2.90 Å) Ge–Ge bond lengths. In the third Ge site, Ge is bonded in a 2-coordinate geometry to two equivalent Ho, two equivalent Ni, and five Ge atoms. The Ge–Ge bond length is 2.48 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoIO9 by Materials Project

HoO9I crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of one HoO9I sheet oriented in the (1, 0, 0) direction. Ho is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Ho–O bond distances ranging from 2.19–2.45 Å. There are nine inequivalent O sites. In the first O site, O is bonded in a water-like geometry to one Ho and one I atom. The O–I bond length is 1.86 Å. In the second O site, O is bonded in a bent 120 degrees geometry to one O and one I atom. The O–O bond length is 1.27 Å. The O–I bond length is 2.27 Å. In the third O site, O is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ho and one I atom. The O–I bond length is 1.95 Å. In the fourth O site, O is bonded in a single-bond geometry to one Ho atom. In the fifth O site, O is bonded in a bent 120 degrees geometry to one O and one I atom. The O–O bond length is 1.27 Å. The O–I bond length is 2.27 Å. In the sixth O site, O is bonded in a water-like geometry to one Ho and one I atom. The O–I bond length is 1.86 Å. In the seventh O site, O is bonded in a single-bond geometry to one O atom. In the eighth O site, O is bonded in a single-bond geometry to one O atom. In the ninth O site, O is bonded in a water-like geometry to one Ho and one I atom. The O–I bond length is 1.86 Å. I is bonded in an octahedral geometry to six O atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho9Sb5CO4 by Materials Project

Ho9CSb5O4 crystallizes in the tetragonal P4/n space group. The structure is three-dimensional. there are three inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded in a distorted single-bond geometry to one C4- and five Sb3- atoms. The Ho–C bond length is 2.26 Å. There are four shorter (3.19 Å) and one longer (3.23 Å) Ho–Sb bond lengths. In the second Ho3+ site, Ho3+ is bonded in a distorted single-bond geometry to five Sb3- and one O2- atom. There are a spread of Ho–Sb bond distances ranging from 3.11–3.18 Å. The Ho–O bond length is 2.21 Å. In the third Ho3+ site, Ho3+ is bonded in a 4-coordinate geometry to one C4-, two equivalent Sb3-, and three equivalent O2- atoms. The Ho–C bond length is 2.42 Å. There are one shorter (3.39 Å) and one longer (3.44 Å) Ho–Sb bond lengths. There are a spread of Ho–O bond distances ranging from 2.21–2.31 Å. C4- is bonded to five Ho3+ atoms to form distorted CHo5 trigonal bipyramids that share a cornercorner with one SbHo5 square pyramid, corners with four equivalent OHo4 tetrahedra, and edges with four equivalent OHo4 tetrahedra. There are two inequivalent Sb3- sites. In the first Sb3- site, Sb3- is bonded to five Ho3+ atoms to form SbHo5 square pyramids that share corners with four equivalent OHo4 tetrahedra and a cornercorner with one CHo5 trigonal bipyramid. In the second Sb3- site, Sb3- is bonded in a 5-coordinate geometry to seven Ho3+ atoms. O2- is bonded to four Ho3+ atoms to form OHo4 tetrahedra that share a cornercorner with one SbHo5 square pyramid, corners with four equivalent OHo4 tetrahedra, a cornercorner with one CHo5 trigonal bipyramid, an edgeedge with one OHo4 tetrahedra, and an edgeedge with one CHo5 trigonal bipyramid.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Effects of Gasoline Composition and Operating Parameters on the Response of End-Gas Autoignition to Nitric Oxide in a Lean-Burn DI-SI Engine

Lean operation of spark-ignition engines can lead to engine thermal efficiency gains and lower NOx emissions due to reduced combustion temperatures. Yet, lean operation could still face challenges in end-gas autoignition and knock generation due to higher intake pressures and trapped NO in the residual gas. Here, this study evaluates the impact of NO on end-gas autoignition for two gasoline fuels with similar octane rating but different composition: high cycloalkane fuel (HCA) and high olefin fuel (HO). Experiments were performed at stoichiometric and lean (λ = 2) conditions and at two engine speeds of 1400 rpm and 2000 rpm. Accompanying chemical kinetics simulations in CHEMKIN revealed that the mechanisms controlling the effect of NO on autoignition are similar λ = 2 and λ = 1, with NO + HO 2 = NO 2 + OH being the main pathway for enhancing reactivity by promoting low-temperature heat release (LTHR). The compositionally different fuels reacted differently to NO seeding and engine speed, and differences were augmented at λ = 2 compared to λ = 1 as the end-gas autoignition shifted to the low temperature regime. HO, which has inherent low temperature chemistry, was strongly impacted by engine speed at low NO seeding levels, with no noticeable peak of LTHR detected at 2000 rpm. On the other hand, LTHR of HCA was marginally affected by shortened residence time at higher engine speed as NO + HO 2 reaction was not greatly affected by shorter time scales, since HO 2 production was sustained even at 2000 rpm to support OH generation from NO + HO 2 . Contrary to HO, HCA exhibited greater sensitivity to NO seeding, as the increased OH production at higher NO concentrations offset the OH-quenching effect of cyclopentane, which accounts for 28.6% of HCA’s composition. Consequently, a sensitivity analysis revealed that fuels with weak inherent low-temperature chemistry, like HCA, are likely to be more sensitive to variations in NO concentration and charge temperature, whereas fuels with strong low temperature chemistry are more sensitive to variations in end-gas λ and intake pressure.

Energy↗
NASA NTRS2007

2.5 MHz Line-Width High-energy, 2 Micrometer Coherent Wind Lidar Transmitter

2 micron solid-state lasers are the primary choice for coherent Doppler wind detection. As wind lidars, they are used for wake vortex and clear air turbulence detection providing air transport safety. In addition, 2 micron lasers are one of the candidates for CO2 detection lidars. The rich CO2 absorption line around 2 micron, combined with the long upper state life of time, has made Ho based 2 micron lasers a viable candidate for CO2 sensing DIAL instrument. The design and fabrication of a compact coherent laser radar transmitter for Troposphere wind sensing is under way. This system is hardened for ground as well as airborne applications. As a transmitter for a coherent wind lidar, this laser has stringent spectral line width and beam quality requirements. Although the absolute wavelength does not have to be fixed for wind detection, to maximize return signal, the output wavelength should avoid atmospheric CO2 and H2O absorption lines. The base line laser material is Ho:Tm:LuLF which is an isomorph of Ho:Tm:YLF. LuLF produces 20% more output power than Ho:Tm:YLF. In these materials the Tm absorption cross-section, the Ho emission cross-section, the Tm to Ho energy transfer parameters and the Ho (sup 5) I (sub 7) radiative life time are all identical. However, the improved performance of the LuLF is attributed to the lower thermal population in the (sup 5) I (sub 8) manifold. It also provides higher normal mode to Q-switch conversion than YLF at high pump energy indicating a lower up-conversion. The laser architecture is composed of a seed laser, a ring oscillator, and a double pass amplifier. The seed laser is a single longitudinal mode with a line width of 13 KHz. The 100mJ class oscillator is stretched to 3 meters to accommodate the line-width requirement without compromising the range resolution of the instrument. The amplifier is double passed to produce greater than 300mJ energy.

Petros, Mulugeta↗
DOE OSTI2020

Materials Data on HoInRh by Materials Project

HoRhIn crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Ho is bonded in a 11-coordinate geometry to five Rh and six equivalent In atoms. There are four shorter (3.01 Å) and one longer (3.05 Å) Ho–Rh bond lengths. There are two shorter (3.20 Å) and four longer (3.32 Å) Ho–In bond lengths. There are two inequivalent Rh sites. In the first Rh site, Rh is bonded in a 9-coordinate geometry to six equivalent Ho and three equivalent In atoms. All Rh–In bond lengths are 2.83 Å. In the second Rh site, Rh is bonded in a 9-coordinate geometry to three equivalent Ho and six equivalent In atoms. All Rh–In bond lengths are 2.76 Å. In is bonded in a 4-coordinate geometry to six equivalent Ho and four Rh atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoCd2 by Materials Project

HoCd2 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Ho is bonded to two equivalent Ho and twelve equivalent Cd atoms to form a mixture of distorted edge, corner, and face-sharing HoHo2Cd12 cuboctahedra. Both Ho–Ho bond lengths are 3.44 Å. All Ho–Cd bond lengths are 3.34 Å. Cd is bonded in a 11-coordinate geometry to six equivalent Ho and five equivalent Cd atoms. There are three shorter (2.87 Å) and two longer (3.44 Å) Cd–Cd bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoMnGa by Materials Project

HoMnGa crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Ho is bonded in a 11-coordinate geometry to five Mn and six equivalent Ga atoms. There are four shorter (2.92 Å) and one longer (2.96 Å) Ho–Mn bond lengths. There are two shorter (3.05 Å) and four longer (3.20 Å) Ho–Ga bond lengths. There are two inequivalent Mn sites. In the first Mn site, Mn is bonded in a 9-coordinate geometry to six equivalent Ho and three equivalent Ga atoms. All Mn–Ga bond lengths are 2.72 Å. In the second Mn site, Mn is bonded in a 9-coordinate geometry to three equivalent Ho and six equivalent Ga atoms. All Mn–Ga bond lengths are 2.74 Å. Ga is bonded in a 10-coordinate geometry to six equivalent Ho and four Mn atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoSnRh by Materials Project

HoRhSn crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Ho is bonded in a 11-coordinate geometry to five Rh and six equivalent Sn atoms. There are four shorter (2.99 Å) and one longer (3.08 Å) Ho–Rh bond lengths. There are two shorter (3.15 Å) and four longer (3.30 Å) Ho–Sn bond lengths. There are two inequivalent Rh sites. In the first Rh site, Rh is bonded in a 9-coordinate geometry to three equivalent Ho and six equivalent Sn atoms. All Rh–Sn bond lengths are 2.76 Å. In the second Rh site, Rh is bonded in a 9-coordinate geometry to six equivalent Ho and three equivalent Sn atoms. All Rh–Sn bond lengths are 2.84 Å. Sn is bonded in a 10-coordinate geometry to six equivalent Ho and four Rh atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoInIr by Materials Project

HoIrIn crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Ho is bonded in a 11-coordinate geometry to five Ir and six equivalent In atoms. There are four shorter (3.02 Å) and one longer (3.04 Å) Ho–Ir bond lengths. There are two shorter (3.21 Å) and four longer (3.32 Å) Ho–In bond lengths. There are two inequivalent Ir sites. In the first Ir site, Ir is bonded in a 9-coordinate geometry to three equivalent Ho and six equivalent In atoms. All Ir–In bond lengths are 2.77 Å. In the second Ir site, Ir is bonded in a 9-coordinate geometry to six equivalent Ho and three equivalent In atoms. All Ir–In bond lengths are 2.83 Å. In is bonded in a 10-coordinate geometry to six equivalent Ho and four Ir atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho2(Ga3Co)3 by Materials Project

Ho2(CoGa3)3 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Ho is bonded in a 11-coordinate geometry to eleven Ga atoms. There are a spread of Ho–Ga bond distances ranging from 2.97–3.03 Å. There are two inequivalent Co sites. In the first Co site, Co is bonded in a 12-coordinate geometry to eight Ga atoms. There are a spread of Co–Ga bond distances ranging from 2.50–2.56 Å. In the second Co site, Co is bonded in a 12-coordinate geometry to eight Ga atoms. There are four shorter (2.52 Å) and four longer (2.55 Å) Co–Ga bond lengths. There are four inequivalent Ga sites. In the first Ga site, Ga is bonded in a 11-coordinate geometry to three equivalent Ho, three Co, and five Ga atoms. There are a spread of Ga–Ga bond distances ranging from 2.73–2.81 Å. In the second Ga site, Ga is bonded in a 10-coordinate geometry to two equivalent Ho, three Co, and five Ga atoms. There are one shorter (2.69 Å) and two longer (2.80 Å) Ga–Ga bond lengths. In the third Ga site, Ga is bonded in a 10-coordinate geometry to two equivalent Ho, two equivalent Co, and six Ga atoms. Both Ga–Ga bond lengths are 2.74 Å. In the fourth Ga site, Ga is bonded in a 10-coordinate geometry to two equivalent Ho, two equivalent Co, and six Ga atoms. The Ga–Ga bond length is 2.72 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho3Si3O10F by Materials Project

Ho3Si3O10F crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are three inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded in a 7-coordinate geometry to six O2- and one F1- atom. There are a spread of Ho–O bond distances ranging from 2.29–2.58 Å. The Ho–F bond length is 2.24 Å. In the second Ho3+ site, Ho3+ is bonded to six O2- and one F1- atom to form HoO6F pentagonal bipyramids that share corners with six SiO4 tetrahedra. There are a spread of Ho–O bond distances ranging from 2.23–2.46 Å. The Ho–F bond length is 2.39 Å. In the third Ho3+ site, Ho3+ is bonded in a 6-coordinate geometry to six O2- and one F1- atom. There are a spread of Ho–O bond distances ranging from 2.25–2.73 Å. The Ho–F bond length is 2.29 Å. There are three inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent HoO6F pentagonal bipyramids and a cornercorner with one SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.64–1.68 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent HoO6F pentagonal bipyramids and corners with two SiO4 tetrahedra. There is two shorter (1.63 Å) and two longer (1.66 Å) Si–O bond length. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent HoO6F pentagonal bipyramids and a cornercorner with one SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two Ho3+ and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ho3+ and two Si4+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two Ho3+ and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to two Ho3+ and one Si4+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ho3+ and one Si4+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Si4+ atoms. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to three Ho3+ and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two Ho3+ and one Si4+ atom. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ho3+ and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ho3+ and one Si4+ atom. F1- is bonded in a 3-coordinate geometry to three Ho3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoInPt by Materials Project

HoPtIn crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Ho is bonded in a 11-coordinate geometry to five Pt and six equivalent In atoms. There are four shorter (3.02 Å) and one longer (3.12 Å) Ho–Pt bond lengths. There are two shorter (3.20 Å) and four longer (3.34 Å) Ho–In bond lengths. There are two inequivalent Pt sites. In the first Pt site, Pt is bonded in a 9-coordinate geometry to three equivalent Ho and six equivalent In atoms. All Pt–In bond lengths are 2.78 Å. In the second Pt site, Pt is bonded in a 9-coordinate geometry to six equivalent Ho and three equivalent In atoms. All Pt–In bond lengths are 2.88 Å. In is bonded in a 10-coordinate geometry to six equivalent Ho and four Pt atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoMn2 by Materials Project

HoMn2 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 four equivalent Ho and twelve equivalent Mn atoms. All Ho–Ho bond lengths are 3.12 Å. All Ho–Mn bond lengths are 2.99 Å. Mn is bonded to six equivalent Ho and six equivalent Mn atoms to form a mixture of edge, face, and corner-sharing MnHo6Mn6 cuboctahedra. All Mn–Mn bond lengths are 2.55 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoAlNi by Materials Project

HoNiAl crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Ho is bonded in a 5-coordinate geometry to five Ni and six equivalent Al atoms. There are four shorter (2.85 Å) and one longer (2.88 Å) Ho–Ni bond lengths. There are two shorter (3.09 Å) and four longer (3.17 Å) Ho–Al bond lengths. There are two inequivalent Ni sites. In the first Ni site, Ni is bonded in a 9-coordinate geometry to three equivalent Ho and six equivalent Al atoms. All Ni–Al bond lengths are 2.54 Å. In the second Ni site, Ni is bonded in a 9-coordinate geometry to six equivalent Ho and three equivalent Al atoms. All Ni–Al bond lengths are 2.71 Å. Al is bonded in a 12-coordinate geometry to six equivalent Ho, four Ni, and two equivalent Al atoms. Both Al–Al bond lengths are 2.82 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoInCu by Materials Project

HoCuIn crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Ho is bonded in a 11-coordinate geometry to five Cu and six equivalent In atoms. There are four shorter (2.99 Å) and one longer (3.05 Å) Ho–Cu bond lengths. There are two shorter (3.18 Å) and four longer (3.32 Å) Ho–In bond lengths. There are two inequivalent Cu sites. In the first Cu site, Cu is bonded in a 9-coordinate geometry to six equivalent Ho and three equivalent In atoms. All Cu–In bond lengths are 2.81 Å. In the second Cu site, Cu is bonded in a 9-coordinate geometry to three equivalent Ho and six equivalent In atoms. All Cu–In bond lengths are 2.74 Å. In is bonded in a 10-coordinate geometry to six equivalent Ho and four Cu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho2Zn17 by Materials Project

Ho2Zn17 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Ho is bonded in a 10-coordinate geometry to nineteen Zn atoms. There are a spread of Ho–Zn bond distances ranging from 3.10–3.45 Å. There are four inequivalent Zn sites. In the first Zn site, Zn is bonded to three equivalent Ho and nine Zn atoms to form distorted ZnHo3Zn9 cuboctahedra that share corners with twenty-three ZnHo2Zn10 cuboctahedra, edges with ten ZnHo2Zn10 cuboctahedra, and faces with twenty ZnHo3Zn9 cuboctahedra. There are a spread of Zn–Zn bond distances ranging from 2.54–2.86 Å. In the second Zn site, Zn is bonded in a 2-coordinate geometry to one Ho and thirteen Zn atoms. There are a spread of Zn–Zn bond distances ranging from 2.64–2.98 Å. In the third Zn site, Zn is bonded to two equivalent Ho and ten Zn atoms to form ZnHo2Zn10 cuboctahedra that share corners with twenty-two ZnHo2Zn10 cuboctahedra, edges with ten ZnHo2Zn10 cuboctahedra, and faces with eighteen ZnHo3Zn9 cuboctahedra. All Zn–Zn bond lengths are 2.59 Å. In the fourth Zn site, Zn is bonded to two equivalent Ho and ten Zn atoms to form distorted ZnHo2Zn10 cuboctahedra that share corners with twenty-four ZnHo2Zn10 cuboctahedra, edges with five ZnHo2Zn10 cuboctahedra, and faces with twenty-one ZnHo3Zn9 cuboctahedra. Both Zn–Zn bond lengths are 2.67 Å.

36 MATERIALS SCIENCE↗