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All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

High-throughput characterization of Lu-doped zirconia

Lu-doped zirconia (LuDZ) was reported in the 1960s to be a poor oxygen ion conductor. However, we identified this system as worthy of reexamination based on the results of a machine learning-based screen for promising oxygen ion conductors, further supported by a physical argument: because Lu is the heaviest and smallest of the lanthanides, it should offer the possibility of high conductivity due to its high polarizability and size compatibility with the zirconia structure. Here the relationship between dopant concentration and conductivity in the LuDZ system was determined using a high throughput experimental methodology in which spatially resolved conductivity was measured across a compositionally graded film, spanning from Zr 0.93 Lu 0.07 O 1.965 to Zr 0.82 Lu 0.18 O 1.91 . The conductivity broadly peaks with composition at 15 cation % Lu, coinciding with the approximate phase boundary of the fully stabilized cubic phase. The composition-dependent conductivity measurements reveal a surprising increase in activation energy for ion transport with increasing Lu content with no change in this trend at the composition of the conductivity maximum. The pre-exponential factor increases sharply with Lu content, but displays a distinct plateau once the conductivity maximum composition is attained. At 500 °C, the conductivity of Zr 0.85 Lu 0.15 O 1.925 is 2 × 10 –3 S cm –1 , approaching that of optimally doped Sc-stabilized zirconia, which has the highest reported conductivity among zirconia compounds. In comparison to other oxide ion conductors, Lu-stabilized zirconia offers the advantage over ceria of negligible electronic conductivity and is easier to process than (La,Sr)(Ga,Mg)O 3-δ .

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Comparative efficacy of 177 Lu and 90 Y for Anti-CD20 Pretargeted Radioimmunotherapy in Murine Lymphoma Xenograft Models

Purpose Pretargeted radioimmunotherapy (PRIT) is a multi-step method of selectively delivering high doses of radiotherapy to tumor cells while minimizing exposure to surrounding tissues. Yttrium-90 ( 90 Y) and lutetium-177 ( 177 Lu) are two of the most promising beta-particle emitting radionuclides used for radioimmunotherapy, which despite having similar chemistries differ distinctly in terms of radiophysical features. These differences may have important consequences for the absorbed dose to tumors and normal organs. Whereas 90 Y has been successfully applied in a number of preclinical and clinical radioimmunotherapy settings, there have been few published pretargeting studies with 177 Lu. We therefore compared the therapeutic potential of targeting either 90 Y or 177 Lu to human B-cell lymphoma xenografts in mice. Methods Parallel experiments evaluating the biodistribution, imaging, dosimetry, therapeutic efficacy, and toxicity were performed in female athymic nude mice bearing either Ramos (Burkitt lymphoma) or Granta (mantle cell lymphoma) xenografts, utilizing an anti-CD20 antibodystreptavidin conjugate (1F5-SA) and an 90 Y- or 177 Lu-labeled 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-biotin second step reagent. Results The two radionuclides displayed comparable biodistributions in tumors and normal organs; however, the absorbed radiation dose delivered to tumor was more than twice as high for 90 Y (1.3 Gy/MBq) as for 177 Lu (0.6 Gy/MBq). More importantly, therapy with 90 Y-DOTAbiotin was dramatically more effective than with 177 Lu-DOTA-biotin, with 100% of Ramos xenograft-bearing mice cured with 37 MBq 90 Y, whereas 0% were cured using identical amounts of 177 Lu-DOTA-biotin. Similar results were observed in mice bearing Granta xenografts, with 80% of the mice cured with 90 Y-PRIT and 0% cured with 177 Lu-PRIT. Toxicities were comparable with both isotopes. Conclusion 90 Y was therapeutically superior to 177 Lu for streptavidin-biotin PRIT approaches in these human lymphoma xenograft models.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2020

Materials Data on Lu(MnGa)6 by Materials Project

Lu(MnGa)6 crystallizes in the orthorhombic Fmmm space group. The structure is three-dimensional. Lu is bonded in a 12-coordinate geometry to eight Mn and twelve Ga atoms. There are four shorter (3.14 Å) and four longer (3.32 Å) Lu–Mn bond lengths. There are eight shorter (3.21 Å) and four longer (3.42 Å) Lu–Ga bond lengths. There are two inequivalent Mn sites. In the first Mn site, Mn is bonded in a 12-coordinate geometry to two equivalent Lu, four equivalent Mn, and four equivalent Ga atoms. All Mn–Mn bond lengths are 2.69 Å. All Mn–Ga bond lengths are 2.46 Å. In the second Mn site, Mn is bonded in a 10-coordinate geometry to one Lu, seven Mn, and six Ga atoms. There are a spread of Mn–Mn bond distances ranging from 2.62–3.10 Å. There are a spread of Mn–Ga bond distances ranging from 2.57–2.79 Å. There are two inequivalent Ga sites. In the first Ga site, Ga is bonded to two equivalent Lu, four equivalent Mn, and six Ga atoms to form a mixture of distorted face and corner-sharing GaLu2Mn4Ga6 cuboctahedra. There are two shorter (2.42 Å) and four longer (2.61 Å) Ga–Ga bond lengths. In the second Ga site, Ga is bonded in a 12-coordinate geometry to two equivalent Lu, six Mn, and four Ga atoms. There are one shorter (2.91 Å) and one longer (3.06 Å) Ga–Ga bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Lu(Fe5Si)2 by Materials Project

LuFe10Si2 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Lu is bonded in a 12-coordinate geometry to sixteen Fe and four equivalent Si atoms. There are a spread of Lu–Fe bond distances ranging from 2.92–3.16 Å. All Lu–Si bond lengths are 3.06 Å. There are four inequivalent Fe sites. In the first Fe site, Fe is bonded in a 10-coordinate geometry to one Lu, eleven Fe, and two equivalent Si atoms. There are a spread of Fe–Fe bond distances ranging from 2.32–2.90 Å. Both Fe–Si bond lengths are 2.60 Å. In the second Fe site, Fe is bonded in a 10-coordinate geometry to one Lu, eleven Fe, and two equivalent Si atoms. There are a spread of Fe–Fe bond distances ranging from 2.41–2.67 Å. Both Fe–Si bond lengths are 2.53 Å. In the third Fe site, Fe is bonded in a 12-coordinate geometry to two equivalent Lu, eight Fe, and two equivalent Si atoms. All Fe–Fe bond lengths are 2.42 Å. Both Fe–Si bond lengths are 2.57 Å. In the fourth Fe site, Fe is bonded to two equivalent Lu, eight Fe, and two equivalent Si atoms to form distorted FeLu2Fe8Si2 cuboctahedra that share corners with four equivalent SiLu2Fe10 cuboctahedra, corners with ten equivalent FeLu2Fe8Si2 cuboctahedra, edges with two equivalent SiLu2Fe10 cuboctahedra, edges with four equivalent FeLu2Fe8Si2 cuboctahedra, faces with four equivalent SiLu2Fe10 cuboctahedra, and faces with six equivalent FeLu2Fe8Si2 cuboctahedra. Both Fe–Fe bond lengths are 2.37 Å. Both Fe–Si bond lengths are 2.38 Å. Si is bonded to two equivalent Lu and ten Fe atoms to form distorted SiLu2Fe10 cuboctahedra that share corners with six equivalent SiLu2Fe10 cuboctahedra, corners with eight equivalent FeLu2Fe8Si2 cuboctahedra, edges with three equivalent SiLu2Fe10 cuboctahedra, edges with four equivalent FeLu2Fe8Si2 cuboctahedra, a faceface with one SiLu2Fe10 cuboctahedra, and faces with eight equivalent FeLu2Fe8Si2 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Lu(CuSn)2 by Materials Project

Lu(CuSn)2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Lu is bonded in a 12-coordinate geometry to eight Cu and eight Sn atoms. All Lu–Cu bond lengths are 3.34 Å. There are four shorter (3.24 Å) and four longer (3.64 Å) Lu–Sn bond lengths. There are two inequivalent Cu sites. In the first Cu site, Cu is bonded in a 12-coordinate geometry to four equivalent Lu, four equivalent Cu, and four equivalent Sn atoms. All Cu–Cu bond lengths are 3.04 Å. All Cu–Sn bond lengths are 2.60 Å. In the second Cu site, Cu is bonded in a 9-coordinate geometry to four equivalent Lu and five Sn atoms. There are one shorter (2.47 Å) and four longer (2.66 Å) Cu–Sn bond lengths. There are two inequivalent Sn sites. In the first Sn site, Sn is bonded to four equivalent Lu and four equivalent Cu atoms to form a mixture of distorted edge and face-sharing SnLu4Cu4 tetrahedra. In the second Sn site, Sn is bonded in a 9-coordinate geometry to four equivalent Lu and five Cu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2012

Growth conditions, structure, Raman characterization and optical properties of Sm-doped (Lu{sub x}Gd{sub 1-x}){sub 2}SiO{sub 5} single crystals grown by the Czochralski method

The (Lu{sub x}Gd{sub 0.995-x}Sm{sub 0.005}){sub 2}SiO{sub 5} single crystals with x=0.095, 0.11, 0.15, 0.17, 0.19 0.35 and 0.5 were grown by the Czochralski method. Structural properties were investigated by X-ray diffraction measurements. Unit cell parameters and cell volume were determined by the Rietveld refinement of the collected X-ray powder spectra. The segregation features between Gd and Lu were estimated and analyzed. Vibrational properties of the solid solutions were analyzed on the basis of polarized Raman spectra acquired at 300-875 K temperature range. Absorption and emission spectra of Sm{sup 3+} ion in the crystals with different composition were analyzed in the terms of dopant energy levels, oscillator strengths of transitions and spectral features of luminescence bands in the visible range. Both structural and optical investigations revealed that change of Lu{sup 3+} content in (Lu{sub x}Gd{sub 0.995-x}Sm{sub 0.005}){sub 2}SiO{sub 5} solid solution crystals induces the phase transition from C2/c (Lu{sub 2}SiO{sub 5}) to P2{sub 1}/c (Gd{sub 2}SiO{sub 5}) structure. It was found that the break of LSO to GSO-type structure occurs at 0.15<x<0.17. - Graphical abstract: Single crystals of Sm{sup 3+}-doped (Lu{sub x}Gd{sub 1-x}){sub 2}SiO{sub 5} solid solutions have been grown by Czochralski method and characterized by various techniques. Crystal structure changes from C2/c to P2{sub 1}/c for composition with 0.15<x<0.17. Change of crystal structure causes changes in emission spectra. Highlights: Black-Right-Pointing-Pointer The (Lu{sub x}Gd{sub 1-x}){sub 2}SiO{sub 5} crystals are an alternative to LSO and GSO hosts for applications. Black-Right-Pointing-Pointer The break of the P2{sub 1}/c to C2/c structure in (Lu{sub x}Gd{sub 1-x}){sub 2}SiO{sub 5}:Sm occurs for 0.15<x<0.17. Black-Right-Pointing-Pointer Temperature-induced phase transition from C2/c to P2{sub 1}/c up to 875 K was not observed. Black-Right-Pointing-Pointer Observed significant changes of emission spectra caused by P2{sub 1}/c to C2/c structural transition.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Growth and luminescent properties of scintillators based on the single crystalline films of Lu{sub 3−x}Gd{sub x}Al{sub 5}O{sub 12}:Ce garnet

Highlights: • Single crystalline films of Lu{sub 3−x}Gd{sub x}Al{sub 5}O{sub 12} garnets at x = 0 ÷ 3.0 were grown by LPE method onto YAG substrates. • Lattice constant of Lu{sub 3−}Gd{sub x}Al{sub 5}O{sub 12}:Ce film and the misfit m between films and YAG substrate changed linearly with increasing of Gd content. • Effective Gd{sup 3+}–Ce{sup 3+} energy transfer occurs in the Lu{sub 3−x}Gd{sub x}Al{sub 5}O{sub 12}:Ce films. • Best scintillation light yield is observed in the Lu{sub 3}Al{sub 5}O{sub 12}:Ce and Lu{sub 2.4}Gd{sub 0.6}Al{sub 5}O{sub 12}:Ce films. • Increase of the Gd content in x = 1.5–2.5 range results in decreasing the scintillation LY of Lu{sub 3−x}Gd{sub x}Al{sub 5}O{sub 12}:Ce films. - Abstract: The work is related to the growth of scintillators based on the single crystalline films (SCF) of Ce{sup 3+} doped Lu{sub 3−}Gd{sub x}Al{sub 5}O{sub 12} mixed rare-earth garnets by Liquid Phase Epitaxy (LPE) method. We have shown, that full set of Lu{sub 3−}Gd{sub x}Al{sub 5}O{sub 12} SCFs with x values ranging from 0 to 3.0 can be successfully crystallized by the LPE method onto Y{sub 3}Al{sub 5}O{sub 12} (YAG) substrates from the melt-solutions based on PbO-B{sub 2}O{sub 3} flux. The absorption, X-ray excited luminescence, photoluminescence, thermoluminescence and light yield measurements, the latter under excitation by α-particles of {sup 239}Pu and {sup 241}Am radioisotopes, were applied for their characterization.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2011

Materials and Electrical Characterization of Physical Vapor Deposited LaxLu1-xO3 Thin Films on 300 mm Silicon

La{sub x}Lu{sub 1-x}O{sub 3} thin films were deposited on 300 mm silicon wafers by physical vapor deposition and fabricated into field-effect transistors using a gate-first process flow. The films were characterized using transmission electron microscopy, Rutherford backscattering spectrometry, and synchrotron x-ray diffraction. The results show the films remain amorphous even at temperatures of 1000 C. The dielectric properties of La{sub x}Lu{sub 1-x}O{sub 3} (0.125 {<=} x {<=} 0.875) thin films were evaluated as a function of film composition. The amorphous La{sub x}Lu{sub 1-x}O{sub 3} thin films have a dielectric constant (K) of 23 across the composition range. The inversion thickness (T{sub inv}) of the La{sub x}Lu{sub 1-x}O{sub 3} thin films was scaled to <1.0 nm.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Nanostructured crystals of fluorite phases Sr{sub 1−x}R{sub x}F{sub 2+x} (R Are Rare Earth Elements) and their ordering: 10. Ordering under spontaneous crystallization and annealing of Sr{sub 1−x}R{sub x}F{sub 2+x} Alloys (R = Tb-Lu, Y) with 23.8–36.1 mol % RF{sub 3}

The products of spontaneous crystallization (at a cooling rate of ∼200 K/min) of Sr{sub 1−x}R{sub x}F{sub 2+x} melts in the homogeneity range of the fluorite phase have been investigated. Thirty-two irrational compositions with 23.8–36.1 mol % RF{sub 3} and eight rational Sr{sub 2}RF{sub 7} compositions are obtained. With respect to the RF{sub 3} content, these compositions form five groups: (1) Sr{sub 0.762}R{sub 0.238}F{sub 2.238} (23.8% RF{sub 3}), (2) Sr{sub 0.744}R{sub 0.256}F{sub 2.256} (25.6%), (3) Sr{sub 0.718}R{sub 0.282}F{sub 2.282} (28.2%), (4) Sr{sub 2}RF{sub 7} (33.3%), and (5) Sr{sub 0.639}R{sub 0.361}F{sub 2.361} (36.1%). R = Tb-Lu, Y for all groups. Quenching melts of group 5 with R = Tb, Dy, and Ho leads to the formation of ordered phases with the trigonal distortion of the rhβ-Na{sub 7}Zr{sub 6}F{sub 31} type, while for melts of group 5 with R = Lu, quenching yields a phase of the trigonal rhα′-Sr{sub 4}Lu{sub 3}F{sub 17} type. In group 5 with R = Y, Er, Tm, or Yb and in groups 1–4 with all REEs, fluorite phases are formed. Annealing at 900 ± 20°C for 96 h with subsequent cooling at a rate of ∼200 K/min expands the variety of ordered phases: a phase with a new r type of orthorhombic distortion is formed in group 1 with R = Lu, in group 2 with R = Tm or Lu, and in group 3 with R = Ho-Lu, Y; a t-Sr{sub 2}RF{sub 7} phase with tetragonal distortion is formed in group 4 with R = Tb-Er, Y; and a phase of trigonal rhα′ type is formed in group 5 with R = Y, Yb, or Lu. A fluorite phase arises in group 1 with R = Tb-Lu, Y as a result of quenching and annealing. The tendency to ordering becomes more pronounced with an increase in the RF{sub 3} content and REE atomic number. The annealing conditions do not provide equilibrium or the completely ordered state of all alloys.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
NASA NTRS1990

Comparative study of computational efficiency of two LU schemes for non-equilibrium reacting flows

The systems of equations governing chemically nonequilibrium flows are solved numerically by two lower-upper(LU) algorithms, namely, LU-SSOR (Yoon and Jameson, 1987) and LU-SW (Steger and Warming, 1981). The methods of flux-Jacobian splitting differentiate the two LU algorithms. The LU-SSOR gives a simpler implicit operator with less temporal damping, while the LU-SW converges faster but requires more computation for each iteration. Relative efficiencies and mutual merits of these two LU algorithms are compared. The results show that LU-SW with upwind-differenced right-hand-side gives the best convergence.

Tsai, Y.-L. Peter↗
DOE OSTI2020

Materials Data on Lu(FeGe)6 by Materials Project

Lu(FeGe)6 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Lu is bonded to twelve equivalent Fe and eight Ge atoms to form distorted face-sharing LuFe12Ge8 hexagonal bipyramids. All Lu–Fe bond lengths are 3.26 Å. There are two shorter (2.81 Å) and six longer (2.94 Å) Lu–Ge bond lengths. Fe is bonded in a 12-coordinate geometry to two equivalent Lu, four equivalent Fe, and six Ge atoms. All Fe–Fe bond lengths are 2.55 Å. There are four shorter (2.51 Å) and two longer (2.66 Å) Fe–Ge bond lengths. There are three inequivalent Ge sites. In the first Ge site, Ge is bonded in a 8-coordinate geometry to one Lu, six equivalent Fe, and one Ge atom. The Ge–Ge bond length is 2.52 Å. In the second Ge site, Ge is bonded in a 6-coordinate geometry to six equivalent Fe atoms. In the third Ge site, Ge is bonded in a 12-coordinate geometry to three equivalent Lu and six equivalent Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Materials Data on Lu(MnAl2)4 by Materials Project

Lu(MnAl2)4 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Lu is bonded in a 4-coordinate geometry to eight equivalent Mn and twelve Al atoms. All Lu–Mn bond lengths are 3.34 Å. There are four shorter (2.92 Å) and eight longer (3.23 Å) Lu–Al bond lengths. Mn is bonded in a 12-coordinate geometry to two equivalent Lu, two equivalent Mn, and eight Al atoms. Both Mn–Mn bond lengths are 2.57 Å. There are four shorter (2.54 Å) and four longer (2.64 Å) Mn–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded in a 10-coordinate geometry to one Lu, four equivalent Mn, and five Al atoms. There are a spread of Al–Al bond distances ranging from 2.74–2.88 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to two equivalent Lu, four equivalent Mn, and six Al atoms. Both Al–Al bond lengths are 2.76 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Materials Data on Lu(Al2Cr)4 by Materials Project

Lu(CrAl2)4 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Lu is bonded in a 12-coordinate geometry to eight equivalent Cr and twelve Al atoms. All Lu–Cr bond lengths are 3.38 Å. There are four shorter (2.96 Å) and eight longer (3.20 Å) Lu–Al bond lengths. Cr is bonded to two equivalent Lu, two equivalent Cr, and eight Al atoms to form distorted CrLu2Al8Cr2 cuboctahedra that share corners with eight equivalent AlLu2Al6Cr4 cuboctahedra, corners with ten equivalent CrLu2Al8Cr2 cuboctahedra, edges with four equivalent CrLu2Al8Cr2 cuboctahedra, edges with four equivalent AlLu2Al6Cr4 cuboctahedra, faces with six equivalent CrLu2Al8Cr2 cuboctahedra, and faces with eight equivalent AlLu2Al6Cr4 cuboctahedra. Both Cr–Cr bond lengths are 2.53 Å. There are four shorter (2.56 Å) and four longer (2.66 Å) Cr–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded in a 10-coordinate geometry to one Lu, four equivalent Cr, and five Al atoms. There are a spread of Al–Al bond distances ranging from 2.72–2.93 Å. In the second Al site, Al is bonded to two equivalent Lu, four equivalent Cr, and six Al atoms to form distorted AlLu2Al6Cr4 cuboctahedra that share corners with eight equivalent CrLu2Al8Cr2 cuboctahedra, corners with ten equivalent AlLu2Al6Cr4 cuboctahedra, edges with three equivalent AlLu2Al6Cr4 cuboctahedra, edges with four equivalent CrLu2Al8Cr2 cuboctahedra, faces with seven equivalent AlLu2Al6Cr4 cuboctahedra, and faces with eight equivalent CrLu2Al8Cr2 cuboctahedra. Both Al–Al bond lengths are 2.77 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Materials Data on Lu(ClO2)3 by Materials Project

Lu(O2Cl)3 crystallizes in the monoclinic P2/c space group. The structure is one-dimensional and consists of two Lu(O2Cl)3 ribbons oriented in the (1, 0, 0) direction. Lu is bonded in a distorted octahedral geometry to six O atoms. There are a spread of Lu–O bond distances ranging from 2.11–2.41 Å. There are three inequivalent O sites. In the first O site, O is bonded in a distorted bent 120 degrees geometry to one Lu and one O atom. The O–O bond length is 1.29 Å. In the second O site, O is bonded in a bent 150 degrees geometry to one Lu and one Cl atom. The O–Cl bond length is 1.57 Å. In the third O site, O is bonded in a bent 150 degrees geometry to one Lu and one Cl atom. The O–Cl bond length is 1.63 Å. There are two inequivalent Cl sites. In the first Cl site, Cl is bonded in a single-bond geometry to one O atom. In the second Cl site, Cl is bonded in a water-like geometry to two equivalent O atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Materials Data on Lu(CoGe)6 by Materials Project

Lu(CoGe)6 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Lu is bonded to twelve equivalent Co and eight Ge atoms to form distorted LuCo12Ge8 hexagonal bipyramids that share faces with twenty-four equivalent CoLu2Co4Ge6 cuboctahedra and faces with six equivalent LuCo12Ge8 hexagonal bipyramids. All Lu–Co bond lengths are 3.20 Å. There are two shorter (2.70 Å) and six longer (2.92 Å) Lu–Ge bond lengths. Co is bonded to two equivalent Lu, four equivalent Co, and six Ge atoms to form distorted CoLu2Co4Ge6 cuboctahedra that share corners with fourteen equivalent CoLu2Co4Ge6 cuboctahedra, edges with seven equivalent CoLu2Co4Ge6 cuboctahedra, faces with nine equivalent CoLu2Co4Ge6 cuboctahedra, and faces with four equivalent LuCo12Ge8 hexagonal bipyramids. All Co–Co bond lengths are 2.53 Å. There are a spread of Co–Ge bond distances ranging from 2.44–2.63 Å. There are three inequivalent Ge sites. In the first Ge site, Ge is bonded in a 12-coordinate geometry to three equivalent Lu and six equivalent Co atoms. In the second Ge site, Ge is bonded in a 6-coordinate geometry to six equivalent Co atoms. In the third Ge site, Ge is bonded in a 8-coordinate geometry to one Lu, six equivalent Co, and one Ge atom. The Ge–Ge bond length is 2.45 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Lu(Al2Cu)4 by Materials Project

Lu(CuAl2)4 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Lu is bonded in a 12-coordinate geometry to eight equivalent Cu and twelve Al atoms. All Lu–Cu bond lengths are 3.37 Å. There are four shorter (3.06 Å) and eight longer (3.19 Å) Lu–Al bond lengths. Cu is bonded in a 12-coordinate geometry to two equivalent Lu, two equivalent Cu, and eight Al atoms. Both Cu–Cu bond lengths are 2.55 Å. There are four shorter (2.57 Å) and four longer (2.69 Å) Cu–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded in a 10-coordinate geometry to one Lu, four equivalent Cu, and five Al atoms. There are a spread of Al–Al bond distances ranging from 2.70–2.84 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to two equivalent Lu, four equivalent Cu, and four equivalent Al atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2011

High-pressure high-temperature synthesis and crystal structure of the isotypic rare earth (RE)-thioborate-sulfides RE{sub 9}[BS{sub 3}]{sub 2}[BS{sub 4}]{sub 3}S{sub 3}, (RE=Dy-Lu)

Application of high-pressure high-temperature conditions (3.5 GPa at 1673 K for 5 h) to mixtures of the elements (RE:B:S=1:3:6) yielded crystalline samples of the isotypic rare earth-thioborate-sulfides RE{sub 9}[BS{sub 3}]{sub 2}[BS{sub 4}]{sub 3}S{sub 3}, (RE=Dy-Lu), which crystallize in space group P6{sub 3} (Z=2/3) and adopt the Ce{sub 6}Al{sub 3.33}S{sub 14} structure type. The crystal structures were refined from X-ray powder diffraction data by applying the Rietveld method. Dy: a=9.4044(2) A, c=5.8855(3) A; Ho: a=9.3703(1) A, c=5.8826(1) A; Er: a=9.3279(12) A, c=5.8793(8) A; Tm: a=9.2869(3) A, c=5.8781(3) A; Yb: a=9.2514(5) A, c=5.8805(6) A; Lu: a=9.2162(3) A, c=5.8911(3) A. The crystal structure is characterized by the presence of two isolated complex ions [BS{sub 3}]{sup 3-} and [BS{sub 4}]{sup 5-} as well as [{open_square}(S{sup 2-}){sub 3}] units. -- Graphical abstract: Isotypic rare earth-thioborate-sulfides RE{sub 9}[BS{sub 3}]{sub 2}[BS{sub 4}]{sub 3}S{sub 3}, (RE=Dy-Lu) were prepared by application of high-pressure high-temperature conditions to mixtures of the elements. Their crystal structures are characterized by presence of the two isolated complex ions [BS{sub 3}]{sup 3-} and [BS{sub 4}]{sup 5-} as well as [{open_square}(S{sup 2-}){sub 3}] units. Quantum mechanical calculations revealed the arrangement of the intrinsic vacancies. Display Omitted Research Highlights: {yields} Application of high-pressure high-temperature conditions to mixtures of the elements yields crystalline samples of the isotypic rare earth-thioborate-sulfides RE{sub 9}[BS{sub 3}]{sub 2}[BS{sub 4}]{sub 3}S{sub 3}, (RE=Dy-Lu). {yields} RE{sub 9}[BS{sub 3}]{sub 2}[BS{sub 4}]{sub 3}S{sub 3}, (RE=Dy-Lu) crystallize in space group P6{sub 3} (Z=2/3) and adopt the Ce{sub 6}Al{sub 3.33}S{sub 14} structure type. {yields} The crystal structure of RE{sub 9}[BS{sub 3}]{sub 2}[BS{sub 4}]{sub 3}S{sub 3}, (RE=Dy-Lu) is characterized by the presence of two isolated complex ions [BS{sub 3}]{sup 3-} and [BS{sub 4}]{sup 5-} as well as [{open_square}(S{sup 2-}){sub 3}] units. {yields} The vacancies in Lu{sub 9}[BS{sub 3}]{sub 2}[BS{sub 4}]{sub 3}S{sub 3} are located at the trigonal planar coordinated boron site with preferred ordering -B2-B2-{open_square}-B2-B2-{open_square}- along [001].

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2012

Monodisperse and core-shell structured SiO{sub 2}-Lu{sub 2}O{sub 3}:Ln{sup 3+} (Ln=Eu, Tb, Dy, Sm, Er, Ho, and Tm) spherical particles: A facile synthesis and luminescent properties

The core-shell structured SiO{sub 2}-Lu{sub 2}O{sub 3}:Ln{sup 3+} particles were realized by coating the Lu{sub 2}O{sub 3}:Ln{sup 3+} phosphors onto the surface of non-aggregated, monodisperse and spherical SiO{sub 2} particles by the Pechini sol-gel method. The as-synthesized products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray (EDX) spectra, scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), photolumiminescence (PL), and low-voltage cathodoluminescence (CL). The results indicate that the 800 Degree-Sign C annealed sample consists of crystalline Lu{sub 2}O{sub 3} shells and amorphous SiO{sub 2} cores, in spherical shape with a narrow size distribution. The as-obtained particles show strong light emission with different colors corresponding to different Ln{sup 3+} ions under ultraviolet-visible light excitation and low-voltage electron beams excitation, which have potential applications in fluorescent lamps and field emission displays. - Graphical Abstract: Representative SEM and TEM images of the core-shell structured SiO{sub 2}-Lu{sub 2}O{sub 3}:Eu{sup 3+} particles; CIE chromaticity diagram showing the emission colors for SiO{sub 2}-Lu{sub 2}O{sub 3}:Ln{sup 3+}; Multicolor emissions of SiO{sub 2}-Lu{sub 2}O{sub 3}:Ln{sup 3+} particles. Highlights: Black-Right-Pointing-Pointer The core-shell particles were realized by coating the phosphors onto the surface of SiO{sub 2} particles. Black-Right-Pointing-Pointer The sample consists of crystalline Lu{sub 2}O{sub 3} shells and amorphous SiO{sub 2} cores. Black-Right-Pointing-Pointer The particles show different light emission colors corresponding to Ln{sup 3+} ions. Black-Right-Pointing-Pointer They have potential applications in fluorescent lamps and field emission displays.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗