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At least 505 records · Page 28
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on NaHo9(Si3O13)2 by Materials Project

NaHo9(SiO4)6O2 crystallizes in the trigonal P3 space group. The structure is three-dimensional. Na1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Na–O bond distances ranging from 2.39–2.91 Å. There are five inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ho–O bond distances ranging from 2.20–2.82 Å. In the second Ho3+ site, Ho3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ho–O bond distances ranging from 2.22–2.69 Å. In the third Ho3+ site, Ho3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ho–O bond distances ranging from 2.30–2.76 Å. In the fourth Ho3+ site, Ho3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ho–O bond distances ranging from 2.30–2.78 Å. In the fifth Ho3+ site, Ho3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are three shorter (2.28 Å) and three longer (2.39 Å) Ho–O bond lengths. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. In the second Si4+ site, Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to three Ho3+ and one Si4+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to three Ho3+ and one Si4+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, two Ho3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a trigonal planar geometry to three equivalent Ho3+ atoms. In the fifth O2- site, O2- is bonded in a trigonal planar geometry to three equivalent Ho3+ atoms. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to three Ho3+ and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, two Ho3+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to three Ho3+ and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, two Ho3+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to two Ho3+ and one Si4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaHo(Pd3O4)2 by Materials Project

NaHo(Pd3O4)2 crystallizes in the cubic Pm-3 space group. The structure is three-dimensional. Na1+ is bonded in a body-centered cubic geometry to eight O2- atoms. All Na–O bond lengths are 2.63 Å. Ho3+ is bonded in a body-centered cubic geometry to eight O2- atoms. All Ho–O bond lengths are 2.42 Å. Pd2+ is bonded in a square co-planar geometry to four O2- atoms. All Pd–O bond lengths are 2.06 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to one Na1+, one Ho3+, and three equivalent Pd2+ atoms to form a mixture of edge and corner-sharing ONaHoPd3 trigonal bipyramids. In the second O2- site, O2- is bonded to one Na1+, one Ho3+, and three equivalent Pd2+ atoms to form a mixture of edge and corner-sharing ONaHoPd3 trigonal bipyramids. All O–Pd bond lengths are 2.06 Å. In the third O2- site, O2- is bonded to one Na1+, one Ho3+, and three equivalent Pd2+ atoms to form a mixture of edge and corner-sharing ONaHoPd3 trigonal bipyramids.

36 MATERIALS SCIENCE↗
NASA NTRS2004

Wind Measurements with High Energy 2 Micron Coherent Doppler Lidar

A coherent Doppler lidar based on an injection seeded Ho:Tm:YLF pulsed laser was developed for wind measurements. A transmitted pulse energy over 75 mJ at 5 Hz repetition rate has been demonstrated. Designs are presented on the laser, injection seeding, receiver, and signal processing subsystems. Sample data of atmospheric measurements are presented including a wind profile extending from the atmospheric boundary layer (ABL) to the free troposphere.

Barnes, Bruce W.↗
DOE OSTI2021

Single Particle Cathodoluminescence Spectroscopy with Sub-20 nm, Electron-Stable Phosphors

Lanthanide-doped nanophosphors have emerged as promising optical labels for high-resolution, "multicolor"electron microscopy. Here, we develop a library of 11 unique lanthanide-doped nanophosphors with average edge lengths of 15.2 ± 2.0 nm (N = 4284). These nanophosphors consist of an electron-stable BaYF5 host lattice doped at 25% atomic concentration with the lanthanides Pr 3+ , Nd 3+ , Sm 3+ , Eu 3+ , Tb 3+ , Dy 3+ , Ce 3+ , Ho 3+ , Er 3+ , Tm 3+ , and Yb 3+ . Under ~100 pA/nm 2 beam beam current in a transmission electron microscope, each nanophosphor species exhibits strong cathodoluminescence spectra with sharp characteristic emission lines for each lanthanide. The bright emission and stability of these nanoparticles enable not only ensemble, but also single-particle cathodoluminescence spectroscopy, which we demonstrate with BaYF 5 :Ln 3+ , where Ln 3+ = Tb 3+ , Ho 3+ , Er 3+ , Sm 3+ , Eu 3+ , or Pr 3+ . Single-particle cathodoluminescence corresponds directly with HAADF intensity across nanoparticles, confirming high spatial localization of the measured cathodoluminescence signal of lanthanide-doped nanophosphors. Furthermore, our synthesis and characterization of sub-20 nm, electron-stable nanophosphors provides a robust material platform to achieve single-molecule labeled correlative cathodoluminescence electron microscopy, a critical foundation for high-resolution correlation of single molecules within the context of cellular ultrastructure.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on Ho2C(NO)2 by Materials Project

Ho2C(NO)2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Ho3+ is bonded in a 7-coordinate geometry to three equivalent N3- and four equivalent O2- atoms. All Ho–N bond lengths are 2.57 Å. There are three shorter (2.23 Å) and one longer (2.29 Å) Ho–O bond lengths. C4+ is bonded in a linear geometry to two equivalent N3- atoms. Both C–N bond lengths are 1.24 Å. N3- is bonded in a 1-coordinate geometry to three equivalent Ho3+ and one C4+ atom. O2- is bonded to four equivalent Ho3+ atoms to form a mixture of corner and edge-sharing OHo4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiHo(SO4)2 by Materials Project

LiHo(SO4)2 crystallizes in the tetragonal P-4n2 space group. The structure is three-dimensional. Li1+ is bonded in a 4-coordinate geometry to four equivalent O2- atoms. All Li–O bond lengths are 1.87 Å. Ho3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.39 Å) and four longer (2.41 Å) Ho–O bond lengths. S6+ is bonded in a tetrahedral geometry to four O2- atoms. There is two shorter (1.48 Å) and two longer (1.52 Å) S–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted T-shaped geometry to one Li1+, one Ho3+, and one S6+ atom. In the second O2- site, O2- is bonded in a distorted water-like geometry to one Ho3+ and one S6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho3Al2(Ni3H4)2 by Materials Project

Ho3Al2(Ni3H4)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Ho sites. In the first Ho site, Ho is bonded in a 4-coordinate geometry to four equivalent H atoms. All Ho–H bond lengths are 2.11 Å. In the second Ho site, Ho is bonded in a 5-coordinate geometry to five H atoms. There are one shorter (2.10 Å) and four longer (2.11 Å) Ho–H bond lengths. There are two inequivalent Ni sites. In the first Ni site, Ni is bonded in a distorted bent 120 degrees geometry to two equivalent Al and two equivalent H atoms. Both Ni–Al bond lengths are 2.44 Å. Both Ni–H bond lengths are 1.65 Å. In the second Ni site, Ni is bonded in a 2-coordinate geometry to two equivalent Al and three H atoms. Both Ni–Al bond lengths are 2.56 Å. There are a spread of Ni–H bond distances ranging from 1.68–2.02 Å. Al is bonded in a distorted linear geometry to six Ni and two equivalent H atoms. Both Al–H bond lengths are 1.99 Å. There are four inequivalent H sites. In the first H site, H is bonded to three Ho and one Al atom to form HHo3Al tetrahedra that share corners with two equivalent HHo2Ni4 octahedra, corners with four equivalent HHo3Al tetrahedra, and edges with three equivalent HHo3Al tetrahedra. The corner-sharing octahedral tilt angles are 49°. In the second H site, H is bonded in a 4-coordinate geometry to four Ni atoms. In the third H site, H is bonded to four equivalent Ni atoms to form edge-sharing HNi4 tetrahedra. In the fourth H site, H is bonded to two equivalent Ho and four equivalent Ni atoms to form HHo2Ni4 octahedra that share corners with eight equivalent HHo3Al tetrahedra and edges with two equivalent HNi4 tetrahedra.

36 MATERIALS SCIENCE↗
NASA NTRS1986

Measurement of atmospheric HO by a chemical method

The parameters for a chemical technique can be outlined from the following set of desirable goals: (1) sufficient conversion of tracer species A to product B that B can be measured quantitatively in the presence of A and a great excess of air; (2) specificity of reaction such that A is converted to B only by reaction with HO; and (3) sufficient sensitivity for detection that the ambient concentration of HO is not seriously perturbed by the presence of A and B. This proposed study involves finding a chemical reaction specific enough for OH, and a measurement of the product formed. What one wants is a rate constant of about 10 to the -10th power cu cm/s, so that 0.1 percent of the OH will be converted in 100 s. Laboratory studies are needed to find a reaction which will fill this bill, yielding a product in quantity sufficient for precise measurement. This is an extremely fast constant and the search may be difficult. Again there is a question of perturbing the local environment, while still providing a sensitive measurement. Also the temperature and pressure dependence of the reaction rate is a complicated function for many of these species (that is, one must use a RRKM or Troe-based picture), and must be taken into account.

Iyer, R. Subramonia↗
DOE OSTI2020

Materials Data on LiHo(WO4)2 by Materials Project

LiHo(WO4)2 crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. Li1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are two shorter (2.04 Å) and two longer (2.17 Å) Li–O bond lengths. Ho3+ is bonded to six O2- atoms to form distorted HoO6 octahedra that share corners with eight equivalent WO6 octahedra. The corner-sharing octahedra tilt angles range from 47–61°. There are a spread of Ho–O bond distances ranging from 2.23–2.34 Å. W6+ is bonded to six O2- atoms to form distorted WO6 octahedra that share corners with four equivalent HoO6 octahedra and edges with two equivalent WO6 octahedra. The corner-sharing octahedra tilt angles range from 47–61°. There are a spread of W–O bond distances ranging from 1.82–2.21 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ho3+ and one W6+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Ho3+, and one W6+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+ and two equivalent W6+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ho3+ and two equivalent W6+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li3Ho3(TeO6)2 by Materials Project

Li3Ho3(TeO6)2 crystallizes in the cubic Ia-3d space group. The structure is three-dimensional. Li1+ is bonded to four equivalent O2- atoms to form LiO4 tetrahedra that share corners with four equivalent TeO6 octahedra. The corner-sharing octahedral tilt angles are 52°. All Li–O bond lengths are 1.89 Å. Ho3+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. There are four shorter (2.36 Å) and four longer (2.47 Å) Ho–O bond lengths. Te6+ is bonded to six equivalent O2- atoms to form TeO6 octahedra that share corners with six equivalent LiO4 tetrahedra. All Te–O bond lengths are 1.96 Å. O2- is bonded in a 4-coordinate geometry to one Li1+, two equivalent Ho3+, and one Te6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on B(HO)3 by Materials Project

H3BO3 is alpha Selenium structured and crystallizes in the trigonal P3_2 space group. The structure is zero-dimensional and consists of three H3BO3 clusters. there are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. All B–O bond lengths are 1.38 Å. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. All B–O bond lengths are 1.38 Å. There are six inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a distorted single-bond geometry to two O2- atoms. There is one shorter (1.00 Å) and one longer (1.67 Å) H–O bond length. In the second H1+ site, H1+ is bonded in a distorted single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the third H1+ site, H1+ is bonded in a distorted single-bond geometry to two O2- atoms. There is one shorter (1.00 Å) and one longer (1.67 Å) H–O bond length. In the fourth H1+ site, H1+ is bonded in a distorted single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the fifth H1+ site, H1+ is bonded in a distorted 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 distorted single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one B3+ and two H1+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one B3+ and one H1+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one B3+ and one H1+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one B3+ and two H1+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one B3+ and one H1+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one B3+ and one H1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr2HoCu3(PbO4)2 by Materials Project

Pb2Sr2HoCu3O8 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.66–2.84 Å. In the second Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.66–2.83 Å. There are two inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Ho–O bond distances ranging from 2.39–2.42 Å. In the second Ho3+ site, Ho3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Ho–O bond distances ranging from 2.39–2.41 Å. There are four inequivalent Cu+1.67+ sites. In the first Cu+1.67+ site, Cu+1.67+ is bonded in a linear geometry to two equivalent O2- atoms. Both Cu–O bond lengths are 1.87 Å. In the second Cu+1.67+ site, Cu+1.67+ is bonded to five O2- atoms to form CuO5 square pyramids that share a cornercorner with one PbO5 square pyramid and corners with four equivalent CuO5 square pyramids. There are four shorter (1.93 Å) and one longer (2.35 Å) Cu–O bond lengths. In the third Cu+1.67+ site, Cu+1.67+ is bonded to five O2- atoms to form CuO5 square pyramids that share a cornercorner with one PbO5 square pyramid and corners with four equivalent CuO5 square pyramids. There are four shorter (1.93 Å) and one longer (2.35 Å) Cu–O bond lengths. In the fourth Cu+1.67+ site, Cu+1.67+ is bonded in a linear geometry to two equivalent O2- atoms. Both Cu–O bond lengths are 1.87 Å. There are two inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded to five O2- atoms to form distorted PbO5 square pyramids that share a cornercorner with one CuO5 square pyramid, corners with four equivalent PbO5 square pyramids, and edges with four equivalent PbO5 square pyramids. There are a spread of Pb–O bond distances ranging from 2.19–3.10 Å. In the second Pb2+ site, Pb2+ is bonded to five O2- atoms to form distorted PbO5 square pyramids that share a cornercorner with one CuO5 square pyramid, corners with four equivalent PbO5 square pyramids, and edges with four equivalent PbO5 square pyramids. There are a spread of Pb–O bond distances ranging from 2.19–3.10 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to two Sr2+, two Ho3+, and two Cu+1.67+ atoms. In the second O2- site, O2- is bonded in a 6-coordinate geometry to two Sr2+, two Ho3+, and two Cu+1.67+ atoms. In the third O2- site, O2- is bonded in a 6-coordinate geometry to two Sr2+, two Ho3+, and two Cu+1.67+ atoms. In the fourth O2- site, O2- is bonded in a 6-coordinate geometry to two Sr2+, two Ho3+, and two Cu+1.67+ atoms. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to one Sr2+, one Cu+1.67+, and four Pb2+ atoms. In the sixth O2- site, O2- is bonded to four Sr2+, one Cu+1.67+, and one Pb2+ atom to form a mixture of distorted edge and corner-sharing OSr4CuPb octahedra. The corner-sharing octahedral tilt angles are 20°. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to one Sr2+, one Cu+1.67+, and four Pb2+ atoms. In the eighth O2- site, O2- is bonded to four Sr2+, one Cu+1.67+, and one Pb2+ atom to form a mixture of distorted edge and corner-sharing OSr4CuPb octahedra. The corner-sharing octahedral tilt angles are 20°.

36 MATERIALS SCIENCE↗
NASA NTRS1988

Phase decorrelation, streamwise vortices and acoustic radiation in mixing layers

Several direct numerical simulations were performed and analyzed to study various aspects of the early development of mixing layers. Included are the phase jitter of the large-scale eddies, which was studied using a 2-D spatially-evolving mixing layer simulation; the response of a time developing mixing layer to various spanwise disturbances; and the sound radiation from a 2-D compressible time developing mixing layer.

Ho, C. M.↗
NASA NTRS2004

Composition and method for hydrogen storage

A method for hydrogen storage includes providing water and hydrogen gas to a containment volume, reducing the temperature of the water and hydrogen gas to form a hydrogen clathrate at a first cryogenic temperature and a first pressure and maintaining the hydrogen clathrate at second cryogenic temperature within a temperature range of up to 250 K to effect hydrogen storage. The low-pressure hydrogen hydrate includes H.sub.2 O molecules, H.sub.2 molecules and a unit cell including polyhedron cages of hydrogen-bonded frameworks of the H.sub.2 O molecules built around the H.sub.2 molecules.

Mao, Wendy L.↗
DOE OSTI2020

Materials Data on NaHoO2 by Materials Project

NaHoO2 is Caswellsilverite-like structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with two equivalent NaO6 octahedra, corners with four HoO6 octahedra, edges with five NaO6 octahedra, and edges with seven HoO6 octahedra. The corner-sharing octahedra tilt angles range from 7–14°. There are a spread of Na–O bond distances ranging from 2.42–2.76 Å. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with two equivalent NaO6 octahedra, corners with four HoO6 octahedra, edges with five NaO6 octahedra, and edges with seven HoO6 octahedra. The corner-sharing octahedra tilt angles range from 1–14°. There are a spread of Na–O bond distances ranging from 2.40–2.74 Å. There are two inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded to six O2- atoms to form HoO6 octahedra that share corners with two equivalent HoO6 octahedra, corners with four NaO6 octahedra, edges with five HoO6 octahedra, and edges with seven NaO6 octahedra. The corner-sharing octahedra tilt angles range from 7–14°. There are a spread of Ho–O bond distances ranging from 2.28–2.32 Å. In the second Ho3+ site, Ho3+ is bonded to six O2- atoms to form HoO6 octahedra that share corners with two equivalent HoO6 octahedra, corners with four NaO6 octahedra, edges with five HoO6 octahedra, and edges with seven NaO6 octahedra. The corner-sharing octahedra tilt angles range from 1–14°. There are a spread of Ho–O bond distances ranging from 2.29–2.31 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to three Na1+ and three Ho3+ atoms to form a mixture of edge and corner-sharing ONa3Ho3 octahedra. The corner-sharing octahedra tilt angles range from 3–13°. In the second O2- site, O2- is bonded to three Na1+ and three Ho3+ atoms to form a mixture of distorted edge and corner-sharing ONa3Ho3 octahedra. The corner-sharing octahedra tilt angles range from 2–13°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho2Ni(B2O5)2 by Materials Project

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

36 MATERIALS SCIENCE↗
NASA NTRS2014

20 years of Tm:Ho:YLF and LuLF Laser Development for Global Winds Measurements

NASA Langley Research Center has a long history of developing 2 micron lasers. From fundamental spectroscopy research, theoretical prediction of new materials, laser demonstration and engineering of lidar systems, it has been a very successful program spanning around two decades. This article covers the program development from the early research to the present instrumentation. A brief historical perspective of Tm:Ho work by early researchers is also given.

Singh, Upendra N.↗
DOE OSTI2020

Materials Data on HoSc(BO3)2 by Materials Project

HoSc(BO3)2 is Calcite-derived structured and crystallizes in the trigonal R-3 space group. The structure is three-dimensional. Ho3+ is bonded to six equivalent O2- atoms to form HoO6 octahedra that share corners with six equivalent ScO6 octahedra. The corner-sharing octahedral tilt angles are 57°. All Ho–O bond lengths are 2.30 Å. Sc3+ is bonded to six equivalent O2- atoms to form ScO6 octahedra that share corners with six equivalent HoO6 octahedra. The corner-sharing octahedral tilt angles are 57°. All Sc–O bond lengths are 2.14 Å. B3+ is bonded in a trigonal planar geometry to three equivalent O2- atoms. All B–O bond lengths are 1.39 Å. O2- is bonded in a distorted trigonal planar geometry to one Ho3+, one Sc3+, and one B3+ atom.

36 MATERIALS SCIENCE↗