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NASA NTRS1995

Ho:Tm:Lu(3)Al(5)O(12) As An Infrared-Laser Material

Material selected on basis of quantum-mechanical modeling of lasing properties. Ho:Tm:Lu(3)Al(5)O(12) features relatively low thermal occupation of lower laser level because this level higher than corresponding levels of most other available laser materials. In addition, it has reasonably large effective cross section for stimulated emission because of contribution of several transitions around central strong transition. Yet another desirable property is its calculated rate of upconversion is lower than those of other laser materials. Inasmuch as upconversion detracts from efficiency of laser, this lower rate of upconversion is highly desirable.

Barnes, Norman P.↗

DOE OSTI2020

Crystal structures and comparisons of huntite aluminum borates RE Al 3 (BO 3 ) 4 ( RE = Tb, Dy and Ho)

Three huntite-type aluminoborates of stoichiometry RE Al 3 (BO 3 ) 4 ( RE = Tb, Dy and Ho), namely, terbium/dysprosium/holmium trialuminium tetrakis(borate), were synthesized by slow cooling within a K 2 Mo 3 O 10 flux with spontaneous crystallization. The crystal structures were determined using single-crystal X-ray diffraction (SC-XRD) data. The synthesized borates are isostructural to the huntite [CaMg 3 (CO 3 ) 4 ] structure and crystallized within the trigonal R 32 space group. The structural parameters were compared to literature data of other huntite RE Al 3 (BO 3 ) 4 crystals within the R 32 space group. All three borates fit well into the trends calculated from the literature data. The unit-cell parameters and volumes increase linearly with larger RE cations whereas the densities decrease. All of the crystals studied were refined as inversion twins.

36 MATERIALS SCIENCE↗

DOE OSTI2022

Evolution of Physical Properties of RE 3 Ni 5 Al 19 Family (RE = Y, Nd, Sm, Gd, Tb, Dy, Ho, and Er)

In this study, single crystals of RE 3 Ni 5 Al 19 series (RE = Y, Nd, Sm, Gd, Tb, Dy, Ho, and Er) are grown using the Al self-flux method. The crystal structure is examined by both single crystal and powder X-ray diffraction. Physical properties are studied for the first time for RE 3 Ni 5 Al 19 (RE = Y, Nd, Gd, Tb, Dy, Ho, and Er) by means of magnetic susceptibility, electrical resistivity, and heat capacity measurements. Complex magnetic behaviors, with up to three transitions present for RE = Sm, Gd, Tb, and Dy, are revealed. Y 3 Ni 5 Al 19 is found to be a nonmagnetic nonsuperconducting metal (above T = 1.8 K) with weak electron–phonon coupling strength.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ho2(Al3Pd)3 by Materials Project

Ho2(PdAl3)3 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Ho is bonded in a 11-coordinate geometry to six Pd and eleven Al atoms. There are two shorter (3.44 Å) and four longer (3.47 Å) Ho–Pd bond lengths. There are a spread of Ho–Al bond distances ranging from 3.05–3.19 Å. There are two inequivalent Pd sites. In the first Pd site, Pd is bonded in a 8-coordinate geometry to four equivalent Ho and eight Al atoms. There are a spread of Pd–Al bond distances ranging from 2.56–2.66 Å. In the second Pd site, Pd is bonded in a 8-coordinate geometry to four equivalent Ho and eight Al atoms. There are a spread of Pd–Al bond distances ranging from 2.55–2.65 Å. There are four inequivalent Al sites. In the first Al site, Al is bonded in a 2-coordinate geometry to two equivalent Ho and two equivalent Pd atoms. In the second Al site, Al is bonded in a 3-coordinate geometry to three equivalent Ho, three Pd, and one Al atom. The Al–Al bond length is 2.86 Å. In the third Al site, Al is bonded in a 3-coordinate geometry to two equivalent Ho, three Pd, and five Al atoms. There are one shorter (2.80 Å) and two longer (2.84 Å) Al–Al bond lengths. In the fourth Al site, Al is bonded in a 2-coordinate geometry to two equivalent Ho, two equivalent Pd, and two equivalent Al atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Crystal Growth and Elemental Homogeneity of the Multicomponent Rare-Earth Garnet (Lu 1/6 Y 1/6 Ho 1/6 Dy 1/6 Tb 1/6 Gd 1/6 ) 3 Al 5 O 12

We report high-entropy aluminum garnets were grown as bulk single crystals using the micro-pulling-down method, taking the synthesis of complex ceramics a step further from the conventional preparation of polycrystalline materials. We studied the effects of growth parameters on the elemental distribution in high optical quality crystals of (Lu 1/6 Y 1/6 Ho 1/6 Dy 1/6 Tb 1/6 Gd 1/6 ) 3 Al 5 O 12 containing six cations (yttrium and rare-earths) taken in equimolar amounts. A single garnet structure was confirmed by powder X-ray diffraction. Electron microprobe measurements were obtained to correlate the radial distribution of rare-earth elements with pulling rates and molten zone height. The nature of the elemental distribution in the radial direction was associated with ionic radius: smaller rare-earths concentrated in the center of the crystal, while larger rare-earths segregated toward the outer edge of the cylindrical crystal. Faster pulling rates led to a flattening of the concentration profiles toward the nominal concentration, promoting a more homogeneous radial elemental distribution, while varying the molten zone height did not have a significant effect. The demonstrated success with crystal growth enables the practical availability of single crystals of multicomponent aluminum garnets for further discovery of new phenomena and applications.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ho2(Al3Ir)3 by Materials Project

Ho2(IrAl3)3 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Ho is bonded in a 11-coordinate geometry to eleven Al atoms. There are a spread of Ho–Al bond distances ranging from 3.04–3.14 Å. There are two inequivalent Ir sites. In the first Ir site, Ir is bonded in a 8-coordinate geometry to eight Al atoms. There are four shorter (2.56 Å) and four longer (2.62 Å) Ir–Al bond lengths. In the second Ir site, Ir is bonded in a 8-coordinate geometry to eight Al atoms. There are a spread of Ir–Al bond distances ranging from 2.55–2.61 Å. There are four inequivalent Al sites. In the first Al site, Al is bonded in a 2-coordinate geometry to two equivalent Ho and two equivalent Ir atoms. In the second Al site, Al is bonded in a 3-coordinate geometry to three equivalent Ho and three Ir atoms. In the third Al site, Al is bonded in a 3-coordinate geometry to two equivalent Ho and three Ir atoms. In the fourth Al site, Al is bonded in a 2-coordinate geometry to two equivalent Ho and two equivalent Ir atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on HoAlGa by Materials Project

HoAlGa is hexagonal omega structure-derived structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Ho is bonded to six equivalent Ga and six equivalent Al atoms to form a mixture of edge and face-sharing HoAl6Ga6 cuboctahedra. All Ho–Ga bond lengths are 3.12 Å. All Ho–Al bond lengths are 3.12 Å. Ga is bonded in a 3-coordinate geometry to six equivalent Ho and three equivalent Al atoms. All Ga–Al bond lengths are 2.57 Å. Al is bonded in a 3-coordinate geometry to six equivalent Ho and three equivalent Ga atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ho3(Al3Ru)4 by Materials Project

Ho3(RuAl3)4 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Ho is bonded in a 5-coordinate geometry to four equivalent Ru and eleven Al atoms. All Ho–Ru bond lengths are 3.37 Å. There are a spread of Ho–Al bond distances ranging from 2.96–3.21 Å. There are two inequivalent Ru sites. In the first Ru site, Ru is bonded in a body-centered cubic geometry to eight Al atoms. There are two shorter (2.40 Å) and six longer (2.58 Å) Ru–Al bond lengths. In the second Ru site, Ru is bonded in a 12-coordinate geometry to four equivalent Ho and eight Al atoms. There are a spread of Ru–Al bond distances ranging from 2.55–2.69 Å. There are four inequivalent Al sites. In the first Al site, Al is bonded in a 3-coordinate geometry to three equivalent Ho and three equivalent Ru atoms. In the second Al site, Al is bonded in a 3-coordinate geometry to three equivalent Ho and three Ru atoms. In the third Al site, Al is bonded in a 2-coordinate geometry to two equivalent Ho and two equivalent Ru atoms. In the fourth Al site, Al is bonded in a distorted linear geometry to three equivalent Ho and two equivalent Ru atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ho3(Al3Os)4 by Materials Project

Ho3(OsAl3)4 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Ho is bonded in a 5-coordinate geometry to four equivalent Os and eleven Al atoms. All Ho–Os bond lengths are 3.37 Å. There are a spread of Ho–Al bond distances ranging from 2.96–3.22 Å. There are two inequivalent Os sites. In the first Os site, Os is bonded in a body-centered cubic geometry to eight Al atoms. There are two shorter (2.39 Å) and six longer (2.59 Å) Os–Al bond lengths. In the second Os site, Os is bonded in a 12-coordinate geometry to four equivalent Ho and eight Al atoms. There are a spread of Os–Al bond distances ranging from 2.55–2.68 Å. There are four inequivalent Al sites. In the first Al site, Al is bonded in a 3-coordinate geometry to three equivalent Ho and three equivalent Os atoms. In the second Al site, Al is bonded in a 3-coordinate geometry to three equivalent Ho and three Os atoms. In the third Al site, Al is bonded in a 2-coordinate geometry to two equivalent Ho and two equivalent Os atoms. In the fourth Al site, Al is bonded in a distorted linear geometry to three equivalent Ho and two equivalent Os atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on HoAl4Ni by Materials Project

HoNiAl4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Ho is bonded in a 11-coordinate geometry to two equivalent Ni and thirteen Al atoms. Both Ho–Ni bond lengths are 3.13 Å. There are a spread of Ho–Al bond distances ranging from 2.98–3.38 Å. Ni is bonded in a 7-coordinate geometry to two equivalent Ho and seven Al atoms. There are a spread of Ni–Al bond distances ranging from 2.32–2.48 Å. There are three inequivalent Al sites. In the first Al site, Al is bonded in a distorted q6 geometry to four equivalent Ho and six Al atoms. There are four shorter (2.86 Å) and two longer (2.91 Å) Al–Al bond lengths. In the second Al site, Al is bonded in a 1-coordinate geometry to three equivalent Ho, one Ni, and four equivalent Al atoms. In the third Al site, Al is bonded in a 3-coordinate geometry to three equivalent Ho, three equivalent Ni, and one Al atom.

36 MATERIALS SCIENCE↗

DOE OSTI2022

Effects of composition and growth parameters on phase formation in multicomponent aluminum garnet crystals

The effects of composition on the phase formation of multicomponent garnet crystals grown via directional solidification by the micro-pulling-down method are studied. A relatively wide range of rare-earth (RE) average ionic radii (AIR) is explored by formulating ten compositions from the system (Lu,Y,Ho,Dy,Tb,Gd) 3 Al 5 O 12 . Crystals were grown at either 0.05 or 0.20 mm min -1 . The hypothesis is that multicomponent compounds with large AIR will form secondary phases as the single-RE aluminum garnets formed by larger Tb 3+ or Gd 3+ ; this will result in crystals of poor optical quality. Crystals with large AIR have a central opaque region in optical microscopy images, which is responsible for their reduced transparency compared to crystals with small AIR. Slow pulling rates suppress the formation of the opaque region in crystals with intermediate AIR. Powder and single-crystal X-ray diffraction and electron probe microanalysis results indicate that the opaque region is a perovskite phase. Scanning electron microscopy and energy dispersive spectroscopy measurements reveal eutectic inclusions at the outer surface of the crystals. Finally, the concentration of the eutectic inclusions increases with increasing AIR.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ho2Al by Materials Project

AlHo2 is Cotunnite 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 5-coordinate geometry to five equivalent Al atoms. There are a spread of Ho–Al bond distances ranging from 3.06–3.41 Å. In the second Ho site, Ho is bonded in a 3-coordinate geometry to five equivalent Al atoms. There are a spread of Ho–Al bond distances ranging from 3.14–3.54 Å. Al is bonded in a 10-coordinate geometry to ten Ho atoms.

36 MATERIALS SCIENCE↗

NASA NTRS1991

Theoretical branching ratios for the 5I7 to 5I7 levels of Ho(3+) in the garnets A3B2C3O12 (A = Y,La,Lu,Gd; B = Al,Lu,Sc,Ga; C = Al,Ga)

Results are reported from an experimental study investigating triply ionized holmium in 10 garnets using the point-change model to predict theoretical energy levels and temperature-dependent branching ratios for the 5I7 to 5I8 manifolds for temperatures between 50 and 400 K. Plots were made for the largest lines at 300 K. YScAG was plotted twice, once for each set of X-ray data available. Energy levels are predicted based on theoretical crystal-field parameters, and good agreement to experiment is found. It is suggested that the present set of theoretical crystal-field parameters provides good estimates of the energy levels for the other hosts on which there are no experimental optical data. X-ray and index-of-refraction data are used to evaluate the performance of 10 lasers via a quantum mechanical model to predict the position of the energy levels and the temperature-dependent branching rations of the 5I7 to 5I8 levels of holmium. The fractional population inversion required for threshold is also evaluated.

Filer, Elizabeth D.↗

DOE OSTI2020

Materials Data on HoAl2Ni by Materials Project

HoNiAl2 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Ho is bonded in a 1-coordinate geometry to three equivalent Ni and ten equivalent Al atoms. There are one shorter (2.81 Å) and two longer (3.03 Å) Ho–Ni bond lengths. There are a spread of Ho–Al bond distances ranging from 3.06–3.28 Å. Ni is bonded in a 9-coordinate geometry to three equivalent Ho and six equivalent Al atoms. There are two shorter (2.46 Å) and four longer (2.51 Å) Ni–Al bond lengths. Al is bonded in a 3-coordinate geometry to five equivalent Ho and three equivalent Ni atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ho(AlCl4)3 by Materials Project

Ho(AlCl4)3 crystallizes in the trigonal P3_112 space group. The structure is one-dimensional and consists of one Ho(AlCl4)3 ribbon oriented in the (0, 0, 1) direction. Ho3+ is bonded in a 8-coordinate geometry to eight Cl1- atoms. There are a spread of Ho–Cl bond distances ranging from 2.72–2.92 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded in a tetrahedral geometry to four Cl1- atoms. There are two shorter (2.16 Å) and two longer (2.17 Å) Al–Cl bond lengths. In the second Al3+ site, Al3+ is bonded in a tetrahedral geometry to four Cl1- atoms. There are a spread of Al–Cl bond distances ranging from 2.10–2.24 Å. There are six inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a distorted L-shaped geometry to one Ho3+ and one Al3+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Al3+ atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one Al3+ atom. In the fourth Cl1- site, Cl1- is bonded in a distorted L-shaped geometry to one Ho3+ and one Al3+ atom. In the fifth Cl1- site, Cl1- is bonded in a distorted L-shaped geometry to one Ho3+ and one Al3+ atom. In the sixth Cl1- site, Cl1- is bonded in an L-shaped geometry to one Ho3+ and one Al3+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ho8(AlGe3)3 by Materials Project

Ho8(AlGe3)3 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are four inequivalent Ho sites. In the first Ho site, Ho is bonded in a 8-coordinate geometry to two equivalent Al and six Ge atoms. Both Ho–Al bond lengths are 3.19 Å. There are a spread of Ho–Ge bond distances ranging from 2.99–3.04 Å. In the second Ho site, Ho is bonded in a 8-coordinate geometry to nine Ge atoms. There are a spread of Ho–Ge bond distances ranging from 3.02–3.60 Å. In the third Ho site, Ho is bonded in a 8-coordinate geometry to two equivalent Al and seven Ge atoms. Both Ho–Al bond lengths are 3.20 Å. There are a spread of Ho–Ge bond distances ranging from 2.98–3.55 Å. In the fourth Ho site, Ho is bonded in a 8-coordinate geometry to two equivalent Al and six Ge atoms. Both Ho–Al bond lengths are 3.19 Å. There are a spread of Ho–Ge bond distances ranging from 3.00–3.04 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded in a 4-coordinate geometry to four Ho and four Ge atoms. There are two shorter (2.65 Å) and two longer (2.67 Å) Al–Ge bond lengths. In the second Al site, Al is bonded in a 4-coordinate geometry to four equivalent Ho and four equivalent Ge atoms. All Al–Ge bond lengths are 2.68 Å. There are five inequivalent Ge sites. In the first Ge site, Ge is bonded in a 9-coordinate geometry to six Ho, two equivalent Al, and one Ge atom. The Ge–Ge bond length is 2.60 Å. In the second Ge site, Ge is bonded in a 9-coordinate geometry to six Ho and three Ge atoms. There are one shorter (2.56 Å) and two longer (2.73 Å) Ge–Ge bond lengths. In the third Ge site, Ge is bonded in a 9-coordinate geometry to six Ho, two equivalent Al, and one Ge atom. In the fourth Ge site, Ge is bonded in a 9-coordinate geometry to six Ho, two equivalent Al, and one Ge atom. In the fifth Ge site, Ge is bonded to eight Ho and four equivalent Ge atoms to form a mixture of distorted edge and face-sharing GeHo8Ge4 cuboctahedra.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ho(AlC)3 by Materials Project

Ho(AlC)3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Ho3+ is bonded to six equivalent C4- atoms to form HoC6 octahedra that share corners with six equivalent AlC4 tetrahedra, edges with six equivalent HoC6 octahedra, and edges with six equivalent AlC4 tetrahedra. All Ho–C bond lengths are 2.54 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four C4- atoms to form AlC4 tetrahedra that share corners with three equivalent HoC6 octahedra, corners with seven equivalent AlC4 tetrahedra, and edges with three equivalent HoC6 octahedra. The corner-sharing octahedral tilt angles are 19°. There are one shorter (2.02 Å) and three longer (2.10 Å) Al–C bond lengths. In the second Al3+ site, Al3+ is bonded in a trigonal planar geometry to three equivalent C4- atoms. All Al–C bond lengths are 1.98 Å. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded in a 6-coordinate geometry to three equivalent Ho3+ and three equivalent Al3+ atoms. In the second C4- site, C4- is bonded to five Al3+ atoms to form corner-sharing CAl5 trigonal bipyramids.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ba6Ho2Al2Rh2O15 by Materials Project

Ba6Ho2Rh2Al2O15 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are four inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.68–3.06 Å. In the second Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ba–O bond distances ranging from 2.79–3.20 Å. In the third Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to eight O2- atoms. There are a spread of Ba–O bond distances ranging from 2.77–3.00 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.91–3.10 Å. Ho3+ is bonded to six O2- atoms to form HoO6 octahedra that share corners with three equivalent RhO5 square pyramids and corners with three equivalent AlO4 tetrahedra. There are a spread of Ho–O bond distances ranging from 2.18–2.34 Å. Rh3+ is bonded to five O2- atoms to form RhO5 square pyramids that share corners with three equivalent HoO6 octahedra and an edgeedge with one RhO5 square pyramid. The corner-sharing octahedra tilt angles range from 3–5°. There are a spread of Rh–O bond distances ranging from 2.03–2.09 Å. Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with three equivalent HoO6 octahedra and a cornercorner with one AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 15–29°. There are a spread of Al–O bond distances ranging from 1.76–1.79 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Ba2+ and two equivalent Al3+ atoms. In the second O2- site, O2- is bonded to four Ba2+ and two equivalent Rh3+ atoms to form distorted OBa4Rh2 octahedra that share corners with ten OBa4Rh2 octahedra, edges with four equivalent OBa4HoRh octahedra, and faces with four OBa4Rh2 octahedra. The corner-sharing octahedra tilt angles range from 2–60°. In the third O2- site, O2- is bonded in a 2-coordinate geometry to three Ba2+, one Ho3+, and one Al3+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to three Ba2+, one Ho3+, and one Al3+ atom. In the fifth O2- site, O2- is bonded in a 6-coordinate geometry to four Ba2+, one Ho3+, and one Rh3+ atom. In the sixth O2- site, O2- is bonded to four Ba2+, one Ho3+, and one Rh3+ atom to form a mixture of distorted edge, corner, and face-sharing OBa4HoRh octahedra. The corner-sharing octahedra tilt angles range from 3–73°.

36 MATERIALS SCIENCE↗