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At least 1,009 records · Page 56
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on TmTe3O8 by Materials Project

TmTe3O8 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Tm is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Tm–O bond distances ranging from 2.33–2.43 Å. There are two inequivalent Te sites. In the first Te site, Te is bonded to five O atoms to form distorted TeO5 square pyramids that share corners with three equivalent TeO6 octahedra and an edgeedge with one TeO5 square pyramid. The corner-sharing octahedra tilt angles range from 50–65°. There are a spread of Te–O bond distances ranging from 1.98–2.27 Å. In the second Te site, Te is bonded to six O atoms to form corner-sharing TeO6 octahedra. There are a spread of Te–O bond distances ranging from 2.05–2.10 Å. There are four inequivalent O sites. In the first O site, O is bonded in a distorted trigonal planar geometry to one Tm and two Te atoms. In the second O site, O is bonded in a distorted trigonal planar geometry to one Tm and two equivalent Te atoms. In the third O site, O is bonded in a distorted trigonal non-coplanar geometry to one Tm and two Te atoms. In the fourth O site, O is bonded in a trigonal planar geometry to one Tm and two Te atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on BaTe3 by Materials Project

BaTe3 is Barium trisulfide structured and crystallizes in the tetragonal P-42_1m space group. The structure is three-dimensional. Ba is bonded in a distorted body-centered cubic geometry to twelve Te atoms. There are a spread of Ba–Te bond distances ranging from 3.65–4.07 Å. There are two inequivalent Te sites. In the first Te site, Te is bonded in a 5-coordinate geometry to four equivalent Ba and two equivalent Te atoms. There are one shorter (2.85 Å) and one longer (3.50 Å) Te–Te bond lengths. In the second Te site, Te is bonded in a 2-coordinate geometry to four equivalent Ba and four equivalent Te atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TaNiTe5 by Materials Project

TaNiTe5 crystallizes in the orthorhombic Cmcm space group. The structure is two-dimensional and consists of two TaNiTe5 sheets oriented in the (0, 1, 0) direction. Ta3+ is bonded in a 8-coordinate geometry to eight Te+0.80- atoms. There are a spread of Ta–Te bond distances ranging from 2.85–2.93 Å. Ni1+ is bonded to six Te+0.80- atoms to form edge-sharing NiTe6 octahedra. There are four shorter (2.59 Å) and two longer (2.61 Å) Ni–Te bond lengths. There are three inequivalent Te+0.80- sites. In the first Te+0.80- site, Te+0.80- is bonded in a 3-coordinate geometry to one Ta3+ and two equivalent Ni1+ atoms. In the second Te+0.80- site, Te+0.80- is bonded in a 3-coordinate geometry to two equivalent Ta3+ and one Ni1+ atom. In the third Te+0.80- site, Te+0.80- is bonded in a distorted L-shaped geometry to two equivalent Ta3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NbNiTe5 by Materials Project

NbNiTe5 crystallizes in the orthorhombic Cmcm space group. The structure is two-dimensional and consists of two NbNiTe5 sheets oriented in the (0, 1, 0) direction. Nb2+ is bonded in a 8-coordinate geometry to eight Te+0.80- atoms. There are a spread of Nb–Te bond distances ranging from 2.86–2.93 Å. Ni2+ is bonded to six Te+0.80- atoms to form edge-sharing NiTe6 octahedra. There are four shorter (2.59 Å) and two longer (2.60 Å) Ni–Te bond lengths. There are three inequivalent Te+0.80- sites. In the first Te+0.80- site, Te+0.80- is bonded in a 3-coordinate geometry to one Nb2+ and two equivalent Ni2+ atoms. In the second Te+0.80- site, Te+0.80- is bonded in a distorted L-shaped geometry to two equivalent Nb2+ atoms. In the third Te+0.80- site, Te+0.80- is bonded in a 3-coordinate geometry to two equivalent Nb2+ and one Ni2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SnTe3 by Materials Project

Te3Sn is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Sn4+ is bonded in a body-centered cubic geometry to eight equivalent Te+1.33- atoms. All Sn–Te bond lengths are 3.34 Å. There are two inequivalent Te+1.33- sites. In the first Te+1.33- site, Te+1.33- is bonded in a distorted body-centered cubic geometry to four equivalent Sn4+ and four equivalent Te+1.33- atoms. All Te–Te bond lengths are 3.34 Å. In the second Te+1.33- site, Te+1.33- is bonded in a body-centered cubic geometry to eight equivalent Te+1.33- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cs4GeTe6 by Materials Project

Cs4GeTe6 is Magnesium tetraboride-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are four inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 8-coordinate geometry to eight Te1- atoms. There are a spread of Cs–Te bond distances ranging from 3.85–4.36 Å. In the second Cs1+ site, Cs1+ is bonded in a 7-coordinate geometry to seven Te1- atoms. There are a spread of Cs–Te bond distances ranging from 3.89–4.29 Å. In the third Cs1+ site, Cs1+ is bonded to eight Te1- atoms to form distorted CsTe8 hexagonal bipyramids that share corners with two equivalent CsTe8 hexagonal bipyramids, corners with two equivalent GeTe4 tetrahedra, an edgeedge with one CsTe8 hexagonal bipyramid, and an edgeedge with one GeTe4 tetrahedra. There are a spread of Cs–Te bond distances ranging from 3.97–4.31 Å. In the fourth Cs1+ site, Cs1+ is bonded in a 8-coordinate geometry to eight Te1- atoms. There are a spread of Cs–Te bond distances ranging from 3.82–4.46 Å. Ge2+ is bonded to four Te1- atoms to form GeTe4 tetrahedra that share corners with two equivalent CsTe8 hexagonal bipyramids and an edgeedge with one CsTe8 hexagonal bipyramid. There are a spread of Ge–Te bond distances ranging from 2.58–2.68 Å. There are six inequivalent Te1- sites. In the first Te1- site, Te1- is bonded in a 6-coordinate geometry to four Cs1+, one Ge2+, and one Te1- atom. The Te–Te bond length is 2.80 Å. In the second Te1- site, Te1- is bonded in a 8-coordinate geometry to six Cs1+ and two Te1- atoms. There are one shorter (2.78 Å) and one longer (3.71 Å) Te–Te bond lengths. In the third Te1- site, Te1- is bonded in a 7-coordinate geometry to five Cs1+ and two Te1- atoms. The Te–Te bond length is 3.60 Å. In the fourth Te1- site, Te1- is bonded in a 1-coordinate geometry to six Cs1+ and one Ge2+ atom. In the fifth Te1- site, Te1- is bonded in a 1-coordinate geometry to six Cs1+, one Ge2+, and one Te1- atom. In the sixth Te1- site, Te1- is bonded in a 6-coordinate geometry to four Cs1+, one Ge2+, and one Te1- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Te2NO6 by Materials Project

N2(TeO3)4 crystallizes in the orthorhombic Pnma space group. The structure is two-dimensional and consists of four ammonia molecules and two TeO3 sheets oriented in the (0, 0, 1) direction. In each TeO3 sheet, there are two inequivalent Te sites. In the first Te site, Te is bonded to five O atoms to form distorted corner-sharing TeO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 39–41°. There are a spread of Te–O bond distances ranging from 1.79–1.97 Å. In the second Te site, Te is bonded to six O atoms to form TeO6 octahedra that share corners with two equivalent TeO6 octahedra and corners with four equivalent TeO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 49°. There is three shorter (1.95 Å) and three longer (1.96 Å) Te–O bond length. There are four inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Te atom. In the second O site, O is bonded in a bent 120 degrees geometry to two equivalent Te atoms. In the third O site, O is bonded in a bent 150 degrees geometry to two Te atoms. In the fourth O site, O is bonded in a bent 150 degrees geometry to two Te atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Zr3Te by Materials Project

Zr3Te crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are three inequivalent Zr sites. In the first Zr site, Zr is bonded in a 9-coordinate geometry to seven Zr and two equivalent Te atoms. There are a spread of Zr–Zr bond distances ranging from 2.83–3.25 Å. Both Zr–Te bond lengths are 3.13 Å. In the second Zr site, Zr is bonded in a distorted trigonal planar geometry to six equivalent Zr and three equivalent Te atoms. All Zr–Te bond lengths are 3.29 Å. In the third Zr site, Zr is bonded to six equivalent Zr and six equivalent Te atoms to form edge-sharing ZrZr6Te6 cuboctahedra. All Zr–Te bond lengths are 3.53 Å. There are two inequivalent Te sites. In the first Te site, Te is bonded in a 9-coordinate geometry to nine Zr atoms. In the second Te site, Te is bonded in a hexagonal planar geometry to six equivalent Zr atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ga2Ni5Te4 by Materials Project

Ni5Ga2Te4 crystallizes in the trigonal P-3m1 space group. The structure is two-dimensional and consists of one Ni5Ga2Te4 sheet oriented in the (0, 0, 1) direction. there are three inequivalent Ni sites. In the first Ni site, Ni is bonded in a 8-coordinate geometry to two Ni, three equivalent Ga, and three equivalent Te atoms. There are one shorter (2.48 Å) and one longer (2.61 Å) Ni–Ni bond lengths. All Ni–Ga bond lengths are 2.60 Å. All Ni–Te bond lengths are 2.53 Å. In the second Ni site, Ni is bonded in a 7-coordinate geometry to one Ni, three equivalent Ga, and three equivalent Te atoms. All Ni–Ga bond lengths are 2.50 Å. All Ni–Te bond lengths are 2.54 Å. In the third Ni site, Ni is bonded in a 6-coordinate geometry to two equivalent Ni and six equivalent Te atoms. All Ni–Te bond lengths are 2.64 Å. Ga is bonded in a 6-coordinate geometry to six Ni atoms. There are two inequivalent Te sites. In the first Te site, Te is bonded in a 6-coordinate geometry to six Ni atoms. In the second Te site, Te is bonded in a 3-coordinate geometry to three equivalent Ni atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsAlTe3 by Materials Project

CsAlTe3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Cs1+ is bonded in a 12-coordinate geometry to ten Te+1.33- atoms. There are a spread of Cs–Te bond distances ranging from 3.94–4.54 Å. Al3+ is bonded to four Te+1.33- atoms to form corner-sharing AlTe4 tetrahedra. There are a spread of Al–Te bond distances ranging from 2.63–2.65 Å. There are three inequivalent Te+1.33- sites. In the first Te+1.33- site, Te+1.33- is bonded in a distorted single-bond geometry to three equivalent Cs1+ and one Al3+ atom. In the second Te+1.33- site, Te+1.33- is bonded in a distorted L-shaped geometry to three equivalent Cs1+ and two equivalent Al3+ atoms. In the third Te+1.33- site, Te+1.33- is bonded in a distorted single-bond geometry to four equivalent Cs1+ and one Al3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(TeMo)6 by Materials Project

BaMo6Te6 crystallizes in the hexagonal P-6 space group. The structure is three-dimensional. Ba is bonded in a 9-coordinate geometry to nine Te atoms. There are six shorter (3.58 Å) and three longer (3.73 Å) Ba–Te bond lengths. There are two inequivalent Mo sites. In the first Mo site, Mo is bonded in a 10-coordinate geometry to six Mo and four Te atoms. There are a spread of Mo–Mo bond distances ranging from 2.68–2.79 Å. There are a spread of Mo–Te bond distances ranging from 2.83–2.89 Å. In the second Mo site, Mo is bonded in a 10-coordinate geometry to six Mo and four Te atoms. Both Mo–Mo bond lengths are 2.66 Å. There are a spread of Mo–Te bond distances ranging from 2.83–2.90 Å. There are two inequivalent Te sites. In the first Te site, Te is bonded in a 6-coordinate geometry to two equivalent Ba and four Mo atoms. In the second Te site, Te is bonded in a 5-coordinate geometry to one Ba and four Mo atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm5Te4Se by Materials Project

Tm5Te4Se is Caswellsilverite-like structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Tm sites. In the first Tm site, Tm is bonded to six Te atoms to form TmTe6 octahedra that share corners with six TmTe4Se2 octahedra and edges with twelve TmTe6 octahedra. The corner-sharing octahedra tilt angles range from 10–11°. All Tm–Te bond lengths are 3.03 Å. In the second Tm site, Tm is bonded to four Te and two equivalent Se atoms to form a mixture of edge and corner-sharing TmTe4Se2 octahedra. The corner-sharing octahedra tilt angles range from 0–11°. There are one shorter (3.09 Å) and three longer (3.12 Å) Tm–Te bond lengths. Both Tm–Se bond lengths are 2.79 Å. In the third Tm site, Tm is bonded to five Te and one Se atom to form a mixture of distorted edge and corner-sharing TmTe5Se octahedra. The corner-sharing octahedra tilt angles range from 0–10°. There are a spread of Tm–Te bond distances ranging from 3.04–3.18 Å. The Tm–Se bond length is 2.75 Å. There are two inequivalent Te sites. In the first Te site, Te is bonded to six Tm atoms to form TeTm6 octahedra that share a cornercorner with one SeTm6 octahedra, corners with five TeTm6 octahedra, edges with two equivalent SeTm6 octahedra, and edges with ten TeTm6 octahedra. The corner-sharing octahedra tilt angles range from 0–14°. In the second Te site, Te is bonded to six Tm atoms to form TeTm6 octahedra that share corners with two equivalent SeTm6 octahedra, corners with four TeTm6 octahedra, edges with three equivalent SeTm6 octahedra, and edges with nine TeTm6 octahedra. The corner-sharing octahedra tilt angles range from 0–14°. Se is bonded to six Tm atoms to form SeTm6 octahedra that share corners with six TeTm6 octahedra, edges with two equivalent SeTm6 octahedra, and edges with ten TeTm6 octahedra. The corner-sharing octahedra tilt angles range from 3–7°.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Ab initio study of mechanical and thermal properties of GeTe-based and PbSe-based high-entropy chalcogenides

GeTe-based and PbSe-based high-entropy compounds have outstanding thermoelectric (TE) performance and crucial applications in mid and high temperatures. Recently, the optimization of TE performance of high-entropy compounds has been focused on reducing thermal conductivity by strengthening the phonon scattering process to improve TE performance. We report a first-principles investigation on nine GeTe-based high-entropy chalcogenide solid solutions constituted of eight metallic elements (Ag, Pb, Sb, Bi, Cu, Cd, Mn, and Sn) and 13 PbSe-based high-entropy chalcogenide solid solutions: Pb 0.99-y Sb 0.012 Sn y Se 1-2x Te x S x (x = 0.1, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, and y = 0) and Pb 0.99-y Sb 0.012 Sn y Se 1-2x Te x S x (y = 0.05, 0.1, 0.15, 0.2, 0.25 and x = 0.25). We have investigated the mechanical properties focusing on Debye temperature (Θ D ), thermal conductivity (κ), Grüneisen parameter (γ α ), dominant phonon wavelength (λ dom ), and melting temperature (T m ). We find that the lattice thermal conductivity is significantly reduced when GeTe is alloyed into the following compositions: Ge 0.75 Sb 0.13 Pb 0.12 Te, Ge 0.61 Ag 0.11 Sb 0.13 Pb 0.12 Bi 0.01 Te, and Ge 0.61 Ag 0.11 Sb 0.13 Pb 0.12 Mn 0.05 Bi 0.01 Te. This reduction is due to the mass increase and strain fluctuations. The results also show that Ge 0.61 Ag 0.11 Sb 0.13 Pb 0.12 Bi 0.01 Te solid solution has the lowest Young’s modulus (30.362 GPa), bulk and shear moduli (18.626 and 12.359 GPa), average sound velocity (1653.128 m/sec), Debye temperature (151.689 K), lattice thermal conductivity (0.574 W.m –1 .K –1 ), dominant phonon wavelength (0.692 Å), and melting temperature (535.91 K). Moreover, Ge 0.61 Ag 0.11 Sb 0.13 Pb 0.12 Bi 0.01 Te has the highest Grüneisen parameter with a reduced and temperature-independent lattice thermal conductivity. The positive correlation between Θ D and κ is revealed. Alloying of PbSe-based high-entropy by Sb, Sn, Te, and S atoms at the Se and Pb sites resulted in much higher shear strains resulted in the reduction of phonon velocity, a reduced Θ D , and a lower lattice thermal conductivity.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2021

Oxygen isotope evidence for input of magmatic fluids and precipitation of Au-Ag-tellurides in an otherwise ordinary adularia-sericite epithermal system in NE China

Abstract Tellurium-rich (Te) adularia-sericite epithermal Au-Ag deposits are an important current and future source of precious and critical metals. However, the source and evolution of ore-forming fluids in these deposits are masked by traditional bulk analysis of quartz oxygen isotope ratios that homogenize fine-scale textures and growth zones. To advance understanding of the source of Te and precious metals, herein, we use petrographic and cathodoluminescence (CL) images of such textures and growth zones to guide high spatial resolution secondary ion mass spectroscopy (SIMS) oxygen isotope analyses (10 µm spot) and spatially correlated fluid inclusion microthermometric measurements on successive quartz bands in contemporary Te-rich and Te-poor adularia-sericite (-quartz) epithermal Au-Ag vein deposits in northeastern China. The results show that large positive oxygen isotope shifts from –7.1 to +7.7‰ in quartz rims are followed by precipitation of Au-Ag telluride minerals in the Te-rich deposit, whereas small oxygen isotope shifts of only 4‰ (–2.2 to +1.6‰) were detected in quartz associated with Au-Ag minerals in the Te-poor deposits. Moreover, fluid-inclusion homogenization temperatures are higher in comb quartz rims (avg. 266.4 to 277.5 °C) followed by Au-Ag telluride minerals than in previous stages (~250 °C) in the Te-rich deposit. The Te-poor deposit has a consistent temperature (~245 °C) in quartz that pre- and postdates Au-Ag minerals. Together, the coupled increase in oxygen isotope ratios and homogenization temperatures followed by precipitation of Au-Ag tellurides strongly supports that inputs of magmatic fluid containing Au, Ag, and Te into barren meteoric water-dominated flow systems are critical to the formation of Te-rich adularia-sericite epithermal Au-Ag deposits. In contrast, Te-poor adularia-sericite epithermal Au-Ag deposits show little or no oxygen isotope or fluid-inclusion evidence for inputs of magmatic fluid.

Geochemistry & Geophysics↗
DOE OSTI2020

Materials Data on PrTe3 by Materials Project

PrTe3 crystallizes in the orthorhombic Cmcm space group. The structure is two-dimensional and consists of two PrTe3 sheets oriented in the (0, 1, 0) direction. Pr4+ is bonded in a 9-coordinate geometry to nine Te+1.33- atoms. There are a spread of Pr–Te bond distances ranging from 3.27–3.40 Å. There are two inequivalent Te+1.33- sites. In the first Te+1.33- site, Te+1.33- is bonded in a 6-coordinate geometry to two equivalent Pr4+ and four equivalent Te+1.33- atoms. All Te–Te bond lengths are 3.12 Å. In the second Te+1.33- site, Te+1.33- is bonded in a 5-coordinate geometry to five equivalent Pr4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LaTe2 by Materials Project

LaTe2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. La3+ is bonded in a 9-coordinate geometry to nine Te+1.50- atoms. There are five shorter (3.34 Å) and four longer (3.42 Å) La–Te bond lengths. There are two inequivalent Te+1.50- sites. In the first Te+1.50- site, Te+1.50- is bonded to five equivalent La3+ atoms to form a mixture of distorted edge and corner-sharing TeLa5 trigonal bipyramids. In the second Te+1.50- site, Te+1.50- is bonded in a 8-coordinate geometry to four equivalent La3+ and four equivalent Te+1.50- atoms. All Te–Te bond lengths are 3.22 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NdTe2 by Materials Project

NdTe2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Nd3+ is bonded in a 9-coordinate geometry to nine Te+1.50- atoms. There are a spread of Nd–Te bond distances ranging from 3.29–3.37 Å. There are two inequivalent Te+1.50- sites. In the first Te+1.50- site, Te+1.50- is bonded to five equivalent Nd3+ atoms to form a mixture of distorted edge and corner-sharing TeNd5 trigonal bipyramids. In the second Te+1.50- site, Te+1.50- is bonded in a 8-coordinate geometry to four equivalent Nd3+ and four equivalent Te+1.50- atoms. All Te–Te bond lengths are 3.19 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Te4O9 by Materials Project

Te4O9 crystallizes in the trigonal R-3 space group. The structure is two-dimensional and consists of three Te4O9 sheets oriented in the (0, 0, 1) direction. there are two inequivalent Te+4.50+ sites. In the first Te+4.50+ site, Te+4.50+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Te–O bond distances ranging from 1.93–2.15 Å. In the second Te+4.50+ site, Te+4.50+ is bonded in an octahedral geometry to six O2- atoms. There is three shorter (1.94 Å) and three longer (1.99 Å) Te–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Te+4.50+ atoms. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent Te+4.50+ atoms. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Te+4.50+ atoms.

36 MATERIALS SCIENCE↗