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At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Ho(GePd)2 by Materials Project

HoPd2Ge2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ho is bonded in a 8-coordinate geometry to eight equivalent Pd and eight equivalent Ge atoms. All Ho–Pd bond lengths are 3.32 Å. All Ho–Ge bond lengths are 3.25 Å. Pd is bonded in a 4-coordinate geometry to four equivalent Ho and four equivalent Ge atoms. All Pd–Ge bond lengths are 2.52 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Ho, four equivalent Pd, and one Ge atom. The Ge–Ge bond length is 2.43 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(CrGe)6 by Materials Project

Ho(CrGe)6 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Ho is bonded to eight Ge atoms to form distorted edge-sharing HoGe8 hexagonal bipyramids. There are two shorter (2.88 Å) and six longer (2.95 Å) Ho–Ge bond lengths. Cr is bonded in a 12-coordinate geometry to six Ge atoms. There are a spread of Cr–Ge bond distances ranging from 2.55–2.68 Å. There are three inequivalent Ge sites. In the first Ge site, Ge is bonded in a 12-coordinate geometry to three equivalent Ho and six equivalent Cr atoms. In the second Ge site, Ge is bonded in a 6-coordinate geometry to six equivalent Cr atoms. In the third Ge site, Ge is bonded in a 8-coordinate geometry to one Ho, six equivalent Cr, and one Ge atom. The Ge–Ge bond length is 2.57 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(SiPt)2 by Materials Project

HoPt2Si2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ho is bonded in a 8-coordinate geometry to eight equivalent Pt and eight equivalent Si atoms. All Ho–Pt bond lengths are 3.23 Å. All Ho–Si bond lengths are 3.18 Å. Pt is bonded to four equivalent Ho and four equivalent Si atoms to form a mixture of distorted edge, face, and corner-sharing PtHo4Si4 tetrahedra. All Pt–Si bond lengths are 2.47 Å. Si is bonded in a 9-coordinate geometry to four equivalent Ho, four equivalent Pt, and one Si atom. The Si–Si bond length is 2.32 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(BO2)3 by Materials Project

Ho(BO2)3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are four inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ho–O bond distances ranging from 2.27–2.59 Å. In the second Ho3+ site, Ho3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ho–O bond distances ranging from 2.28–2.54 Å. In the third Ho3+ site, Ho3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ho–O bond distances ranging from 2.27–2.84 Å. In the fourth Ho3+ site, Ho3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ho–O bond distances ranging from 2.32–2.64 Å. There are six inequivalent B3+ sites. In the first B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.45–1.53 Å. In the second B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There is one shorter (1.47 Å) and three longer (1.48 Å) B–O bond length. In the third B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.46–1.54 Å. In the fourth B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.45–1.54 Å. In the fifth B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.45–1.53 Å. In the sixth B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.46–1.52 Å. There are fifteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ho3+ and two B3+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Ho3+ and two B3+ atoms. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Ho3+ and two equivalent B3+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ho3+ and two B3+ atoms. In the fifth O2- site, O2- is bonded in a trigonal planar geometry to three B3+ atoms. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ho3+ and two B3+ atoms. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Ho3+ and two B3+ atoms. In the eighth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ho3+ and two B3+ atoms. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to two Ho3+ and two B3+ atoms. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ho3+ and two equivalent B3+ atoms. In the eleventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ho3+ and two equivalent B3+ atoms. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to three Ho3+ and one B3+ atom. In the thirteenth O2- site, O2- is bonded in a bent 120 degrees geometry to one Ho3+ and two equivalent B3+ atoms. In the fourteenth O2- site, O2- is bonded in a 2-coordinate geometry to two Ho3+ and two equivalent B3+ atoms. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ho3+ and two equivalent B3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(ClO4)3 by Materials Project

Ho(O4Cl)3 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. Ho is bonded in a 9-coordinate geometry to nine O atoms. There are six shorter (2.40 Å) and three longer (2.44 Å) Ho–O bond lengths. There are three inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Cl atom. The O–Cl bond length is 1.42 Å. In the second O site, O is bonded in a bent 150 degrees geometry to one Ho and one Cl atom. The O–Cl bond length is 1.47 Å. In the third O site, O is bonded in a bent 150 degrees geometry to one Ho and one Cl atom. The O–Cl bond length is 1.47 Å. Cl is bonded in a tetrahedral geometry to four O atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(PO3)3 by Materials Project

Ho(PO3)3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are four inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded to six O2- atoms to form HoO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Ho–O bond distances ranging from 2.24–2.29 Å. In the second Ho3+ site, Ho3+ is bonded to six O2- atoms to form HoO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Ho–O bond distances ranging from 2.22–2.27 Å. In the third Ho3+ site, Ho3+ is bonded to six O2- atoms to form HoO6 octahedra that share corners with six PO4 tetrahedra. There are four shorter (2.25 Å) and two longer (2.27 Å) Ho–O bond lengths. In the fourth Ho3+ site, Ho3+ is bonded to six O2- atoms to form HoO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Ho–O bond distances ranging from 2.24–2.26 Å. There are nine inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two HoO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 9–29°. There are a spread of P–O bond distances ranging from 1.49–1.61 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two HoO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 17–27°. There are a spread of P–O bond distances ranging from 1.49–1.61 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two HoO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 24–48°. There are a spread of P–O bond distances ranging from 1.50–1.62 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two HoO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 30–37°. There is two shorter (1.50 Å) and two longer (1.61 Å) P–O bond length. In the fifth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two HoO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedral tilt angles are 31°. There are a spread of P–O bond distances ranging from 1.50–1.61 Å. In the sixth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two HoO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 25–35°. There are a spread of P–O bond distances ranging from 1.50–1.62 Å. In the seventh P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent HoO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 10–26°. There is two shorter (1.50 Å) and two longer (1.60 Å) P–O bond length. In the eighth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent HoO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 29–38°. There are a spread of P–O bond distances ranging from 1.50–1.62 Å. In the ninth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two HoO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 26–30°. There is two shorter (1.50 Å) and two longer (1.61 Å) P–O bond length. There are twenty-seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Ho3+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ho3+ and one P5+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Ho3+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ho3+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the sixth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ho3+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a linear geometry to one Ho3+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a distorted linear geometry to one Ho3+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Ho3+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ho3+ and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ho3+ and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ho3+ and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ho3+ and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ho3+ and one P5+ atom. In the seventeenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ho3+ and one P5+ atom. In the eighteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ho3+ and one P5+ atom. In the nineteenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ho3+ and one P5+ atom. In the twentieth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two P5+ atoms. In the twenty-first O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the twenty-second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two P5+ atoms. In the twenty-third O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the twenty-fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the twenty-fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two P5+ atoms. In the twenty-sixth O2- site, O2- is bonded in a linear geometry to one Ho3+ and one P5+ atom. In the twenty-seventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Ho3+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(BC)2 by Materials Project

HoB2C2 crystallizes in the tetragonal P4_2/mmc space group. The structure is three-dimensional. Ho is bonded in a 8-coordinate geometry to eight equivalent B and eight equivalent C atoms. All Ho–B bond lengths are 2.73 Å. All Ho–C bond lengths are 2.70 Å. B is bonded in a 2-coordinate geometry to four equivalent Ho and two equivalent C atoms. Both B–C bond lengths are 1.60 Å. C is bonded in a 2-coordinate geometry to four equivalent Ho, two equivalent B, and one C atom. The C–C bond length is 1.42 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(Fe2Ge)2 by Materials Project

HoFe4Ge2 crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. Ho is bonded in a 6-coordinate geometry to twelve equivalent Fe and six equivalent Ge atoms. There are four shorter (3.17 Å) and eight longer (3.27 Å) Ho–Fe bond lengths. There are two shorter (2.91 Å) and four longer (2.94 Å) Ho–Ge bond lengths. Fe is bonded in a 3-coordinate geometry to three equivalent Ho and three equivalent Ge atoms. There are one shorter (2.43 Å) and two longer (2.44 Å) Fe–Ge bond lengths. Ge is bonded in a 9-coordinate geometry to three equivalent Ho and six equivalent Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho by Materials Project

Ho is Copper structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Ho is bonded to twelve equivalent Ho atoms to form a mixture of corner, edge, and face-sharing HoHo12 cuboctahedra. All Ho–Ho bond lengths are 3.52 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho by Materials Project

Ho is Magnesium structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Ho is bonded to twelve equivalent Ho atoms to form a mixture of face, edge, and corner-sharing HoHo12 cuboctahedra. There are six shorter (3.48 Å) and six longer (3.61 Å) Ho–Ho bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho by Materials Project

Ho is Tungsten structured and crystallizes in the cubic Im-3m space group. The structure is three-dimensional. Ho is bonded in a distorted body-centered cubic geometry to eight equivalent Ho atoms. All Ho–Ho bond lengths are 3.45 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Time-resolved measurements of HO 2 radical in a heated plasma flow reactor

Time-resolved, absolute HO 2 number density in diluted H 2 –O 2 –Ar, CH 4 –O 2 -Ar, and C 2 H 4 –O 2 –Ar mixtures excited by a repetitive ns pulse discharge in a heated plasma flow reactor is measured by Cavity Ringdown Spectroscopy (CRDS). The experimental results are obtained at $\textit{T}$ = 300-600 K and $\textit{P}$ = 130 Torr, both during the discharge pulse burst and in the afterglow. In this work, the HO 2 number density is inferred from the CRDS data using a spectral model exhibiting good agreement with previous measurements of absolute HO 2 absorption cross sections. In the room-temperature H 2 –O 2 mixture, as well as in CH 4 –O 2 and C 2 H 4 –O 2 mixtures over the entire temperature range studied, HO2 is generated only during the discharge burst and decays in the afterglow. However, in the H 2 –O 2 mixture at elevated temperatures, $\textit{T}$ = 400-600 K, HO 2 persists in the afterglow up to 10 ms after the discharge burst, comparable with the flow residence time in the reactor. Comparison with kinetic modeling shows that the sustained reactivity after the source of radicals is turned off is due to a chain propagation / hydrogen oxidation process, which dominates the radical recombination reactions. The kinetic modeling predictions are in good agreement with the relative HO 2 number density measured in all three mixtures, although the model underpredicts the absolute number densities in H 2 –O 2 at $\textit{T}$ = 400-600 K by up to a factor of two. Detection of the sustained low-temperature reactivity in H 2 –O 2 , initiated by the radical generation in the plasma, suggests that the plasma excitation may also affect kinetics of oxidation and reforming of fuels exhibiting low-temperature chemistry below hot ignition point.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2024

Local site behavior of the 5$d$ and 4$f$ ions in the frustrated pyrochlore Ho 2 Os 2 O 7

The pyrochlore osmate Ho 2 Os 2 O 7 is a candidate material for a fragile J=0 local singlet ground state, however little is known regarding the single-ion behavior of either the Os or Ho ions. To address this we present polarized neutron powder diffraction (PNPD) and resonant inelastic x-ray scattering (RIXS) measurements that separately probe the local site behavior of the Os and Ho ions. The PNPD results are dominated by Ho 3+ scattering and the analysis reveals local site susceptibility behavior consistent with spin ice materials. Complimentary unpolarized neutron powder diffraction show an ordered spin ice ground state in an applied magnetic field. To isolate the Os 4+ single-ion behavior we present resonant inelastic x-ray scattering (RIXS) measurements at the osmium L-edge. Analysis of the RIXS spectra parameterize the spin-orbit coupling (0.35 eV), Hund’s coupling (0.27 eV) and trigonal distortion (-0.17 eV). Here, the results are considered within the context of a J=0 model and possible departures from this through structural distortions, excitonic interactions and 5d-4f interactions between the Os ion and the surrounding Ho lattice. The experimental methodology employed highlights the complimentary information available in rare earth based 5d pyrochlores from distinct neutron and x-ray scattering techniques that allow for the isolation and determination of the behavior of the different ions.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
NASA NTRS1991

Investigation of loss processes of Tm and Tm,Ho in YAG

The loss of excitation from various manifolds of Tm and Tm,Ho in YAG as a function of temperature and concentration is studied. Two probable loss mechanisms - a Tm up-conversion and a Ho up-conversion - are identified. A 785-nm CW diode laser with 400-nW peak power was focused to a small spot on the sample. The emission from the sample observed at 90 deg was monitored through a monochromator with slits open to 3 mm. Intensity of emission was measured by varying the power of the excitation source using a set of neutral density filters. Power is reported as the percentage of the peak power, and the intensity curves were normalized below 20 percent of transmission. The fact that there is emission above the pump energy indicates an up-conversion from excited manifolds. Nonlinear changes in the intensity of the emission from the Tm 3F4 manifold with the pump power reveals a loss of excitation from this manifold. The linear dependence of the 5I7 manifold emission with pump power at low Tm and high Ho concentrations and the gain of energy in the 5I6 manifold of Ho indicate that the 5I7 manifold loss is due to the coupling of Tm and Ho ions.

Armagan, G.↗
NASA NTRS1991

Comparison of spectroscopic properties of Tm and Ho in YAG and YLF crystals

The paper compares the cross-relaxation, energy transfer and loss processes in Tm- and Ho-doped YAG and YLF as a function of temperature, Tm concentration, and excitation power. Significant differences in the behavior of Tm and Tm,Ho in YAG and YLF crystals were found. The cross-relaxation rates of Tm(6 pct) are faster in YLF (about 5 microsec) than YAG (about 10 microsec). The energy transfer rates between Tm and Ho are faster in YLF than YAG. The time it takes for the maximum intensity of 1.7-micron emission to drop 10 percent is 25 microsec for YLF:Tm(6 pct),Ho(0.6 pct) and 65 microsec YAG:Tm(6 pct),Ho(0.5 pct). The losses occurring with increasing pump power for 2.1-micron emission of the above samples are 30 percent less in YLF than YAG. These qualitative differences point to YLF as a valuable 2-micron laser host material.

Armagan, G.↗
DOE OSTI2020

Materials Data on Ho(MnSn)6 by Materials Project

HoMn6Sn6 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Ho is bonded to eight Sn atoms to form distorted edge-sharing HoSn8 hexagonal bipyramids. There are two shorter (3.00 Å) and six longer (3.15 Å) Ho–Sn bond lengths. Mn is bonded in a 12-coordinate geometry to six Sn atoms. There are a spread of Mn–Sn bond distances ranging from 2.73–2.83 Å. There are three inequivalent Sn sites. In the first Sn site, Sn is bonded in a 8-coordinate geometry to one Ho, six equivalent Mn, and one Sn atom. The Sn–Sn bond length is 3.00 Å. In the second Sn site, Sn is bonded in a 6-coordinate geometry to six equivalent Mn atoms. In the third Sn site, Sn is bonded in a 12-coordinate geometry to three equivalent Ho and six equivalent Mn atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(CuS)2 by Materials Project

Ho(CuS)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Ho is bonded to six equivalent S atoms to form distorted HoS6 octahedra that share corners with twelve equivalent CuS4 tetrahedra, edges with six equivalent HoS6 octahedra, and edges with six equivalent CuS4 tetrahedra. All Ho–S bond lengths are 2.82 Å. Cu is bonded to four equivalent S atoms to form distorted CuS4 tetrahedra that share corners with six equivalent HoS6 octahedra, corners with six equivalent CuS4 tetrahedra, edges with three equivalent HoS6 octahedra, and edges with three equivalent CuS4 tetrahedra. The corner-sharing octahedra tilt angles range from 24–54°. There are three shorter (2.33 Å) and one longer (2.49 Å) Cu–S bond lengths. S is bonded in a 7-coordinate geometry to three equivalent Ho and four equivalent Cu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(Ni2As)2 by Materials Project

Ho(Ni2As)2 crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. Ho is bonded to six equivalent As atoms to form a mixture of distorted corner and edge-sharing HoAs6 octahedra. The corner-sharing octahedral tilt angles are 40°. There are two shorter (2.89 Å) and four longer (2.91 Å) Ho–As bond lengths. Ni is bonded in a 3-coordinate geometry to three equivalent As atoms. All Ni–As bond lengths are 2.40 Å. As is bonded in a 9-coordinate geometry to three equivalent Ho and six equivalent Ni atoms.

36 MATERIALS SCIENCE↗