Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Tm”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 397 records · Page 22
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Revisiting the assignment of atomic charges in metal oxides based on core-level x-ray photoelectron spectra: The case of Ti in SrTiO3(001)

We demonstrate that assigning formal charges to transition metal (TM) cations based on core-level (CL) x-ray photoemission binding energies in oxides leads to physically inconsistent pictures of electronic structure. O 2p–TM 3d hybridization is well known to result in significant covalency in TM–O bonds, thereby reducing TM cation charges from their fully ionic values. However, the ionic bonding model remains the working paradigm for assigning TM CL features, and the resulting cation charges are often taken to be representative of the material under study. Here, we show that a more physically meaningful way to assign charges is to extract information about charge distributions utilizing Dirac–Hartree–Fock theory to calculate CL spectra from first principles and then use the resulting wave functions to determine charges based on orbital occupancies. TM cation charges can also be determined using density functional theory and Bader population analysis. We illustrate these two methods using the Ti 2p spectrum for SrTiO3(001) and show that the agreement between them is excellent. Significantly, the resulting Ti charge is considerably lower than the formal charge. The high degree of similarity between the Ti 2p spectrum for SrTiO3 and those for the rutile and anatase polymorphs of TiO2 suggests that the charge densities surrounding Ti in the latter materials are similar to that in SrTiO3. Taking a broader perspective, oxides containing other first-row transition metals also exhibit covalent character, leading to TM cation charges lower than the analogous fully ionic values in these materials as well.

Chambers, Scott A. (ORCID:000000025415043X)↗
DOE OSTI2020

Materials Data on TmCd2 by Materials Project

TmCd2 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Tm is bonded to two equivalent Tm and twelve equivalent Cd atoms to form a mixture of distorted face, edge, and corner-sharing TmTm2Cd12 cuboctahedra. Both Tm–Tm bond lengths are 3.41 Å. All Tm–Cd bond lengths are 3.33 Å. Cd is bonded in a 11-coordinate geometry to six equivalent Tm and five equivalent Cd atoms. There are three shorter (2.86 Å) and two longer (3.41 Å) Cd–Cd bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm2NiAs2 by Materials Project

Tm2NiAs2 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Tm is bonded in a 9-coordinate geometry to three equivalent Ni and six As atoms. All Tm–Ni bond lengths are 2.99 Å. There are three shorter (2.87 Å) and three longer (2.99 Å) Tm–As bond lengths. Ni is bonded in a 3-coordinate geometry to six equivalent Tm and three equivalent As atoms. All Ni–As bond lengths are 2.35 Å. There are two inequivalent As sites. In the first As site, As is bonded to six equivalent Tm atoms to form edge-sharing AsTm6 octahedra. In the second As site, As is bonded in a 3-coordinate geometry to six equivalent Tm and three equivalent Ni atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TmSnRh by Materials Project

TmRhSn crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Tm is bonded in a 11-coordinate geometry to five Rh and six equivalent Sn atoms. There are four shorter (2.97 Å) and one longer (3.06 Å) Tm–Rh bond lengths. There are two shorter (3.13 Å) and four longer (3.28 Å) Tm–Sn bond lengths. There are two inequivalent Rh sites. In the first Rh site, Rh is bonded in a 9-coordinate geometry to three equivalent Tm and six equivalent Sn atoms. All Rh–Sn bond lengths are 2.75 Å. In the second Rh site, Rh is bonded in a 9-coordinate geometry to six equivalent Tm and three equivalent Sn atoms. All Rh–Sn bond lengths are 2.82 Å. Sn is bonded in a 10-coordinate geometry to six equivalent Tm and four Rh atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm2Al3Si2 by Materials Project

Tm2Al3Si2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Tm is bonded in a 12-coordinate geometry to six Al and five equivalent Si atoms. There are a spread of Tm–Al bond distances ranging from 3.00–3.22 Å. There are a spread of Tm–Si bond distances ranging from 2.85–2.98 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded in a distorted water-like geometry to four equivalent Tm and two equivalent Si atoms. Both Al–Si bond lengths are 2.60 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to four equivalent Tm and two equivalent Si atoms. Both Al–Si bond lengths are 2.71 Å. Si is bonded in a 9-coordinate geometry to five equivalent Tm, three Al, and one Si atom. The Si–Si bond length is 2.38 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TmGa3Ru by Materials Project

TmRuGa3 crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Tm is bonded in a 8-coordinate geometry to four equivalent Ru and ten Ga atoms. All Tm–Ru bond lengths are 3.20 Å. There are eight shorter (2.93 Å) and two longer (3.20 Å) Tm–Ga bond lengths. Ru is bonded to four equivalent Tm and eight equivalent Ga atoms to form distorted RuTm4Ga8 cuboctahedra that share corners with four equivalent RuTm4Ga8 cuboctahedra, edges with four equivalent GaTm6 octahedra, and faces with eight equivalent RuTm4Ga8 cuboctahedra. All Ru–Ga bond lengths are 2.66 Å. There are two inequivalent Ga sites. In the first Ga site, Ga is bonded to six equivalent Tm atoms to form GaTm6 octahedra that share corners with six equivalent GaTm6 octahedra and edges with twelve equivalent RuTm4Ga8 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. In the second Ga site, Ga is bonded in a 6-coordinate geometry to three equivalent Tm and three equivalent Ru atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TmAgPb by Materials Project

TmAgPb crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Tm is bonded in a 5-coordinate geometry to six equivalent Ag and five Pb atoms. There are two shorter (3.31 Å) and four longer (3.62 Å) Tm–Ag bond lengths. There are four shorter (3.18 Å) and one longer (3.24 Å) Tm–Pb bond lengths. Ag is bonded in a 12-coordinate geometry to six equivalent Tm, two equivalent Ag, and four Pb atoms. Both Ag–Ag bond lengths are 3.18 Å. There are two shorter (2.88 Å) and two longer (2.93 Å) Ag–Pb bond lengths. There are two inequivalent Pb sites. In the first Pb site, Pb is bonded in a distorted q6 geometry to three equivalent Tm and six equivalent Ag atoms. In the second Pb site, Pb is bonded in a 9-coordinate geometry to six equivalent Tm and three equivalent Ag atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TmInRh by Materials Project

TmRhIn crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Tm is bonded in a 11-coordinate geometry to five Rh and six equivalent In atoms. There are four shorter (3.00 Å) and one longer (3.03 Å) Tm–Rh bond lengths. There are two shorter (3.18 Å) and four longer (3.30 Å) Tm–In bond lengths. There are two inequivalent Rh sites. In the first Rh site, Rh is bonded in a 9-coordinate geometry to six equivalent Tm and three equivalent In atoms. All Rh–In bond lengths are 2.81 Å. In the second Rh site, Rh is bonded in a 9-coordinate geometry to three equivalent Tm and six equivalent In atoms. All Rh–In bond lengths are 2.75 Å. In is bonded in a 4-coordinate geometry to six equivalent Tm and four Rh atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TmAgSn by Materials Project

TmAgSn crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Tm is bonded in a 11-coordinate geometry to six equivalent Ag and five Sn atoms. There are two shorter (3.26 Å) and four longer (3.55 Å) Tm–Ag bond lengths. There are four shorter (3.13 Å) and one longer (3.17 Å) Tm–Sn bond lengths. Ag is bonded to six equivalent Tm, two equivalent Ag, and four Sn atoms to form a mixture of distorted edge, face, and corner-sharing AgTm6Ag2Sn4 cuboctahedra. Both Ag–Ag bond lengths are 3.15 Å. There are two shorter (2.83 Å) and two longer (2.88 Å) Ag–Sn bond lengths. There are two inequivalent Sn sites. In the first Sn site, Sn is bonded in a 9-coordinate geometry to six equivalent Tm and three equivalent Ag atoms. In the second Sn site, Sn is bonded in a 9-coordinate geometry to three equivalent Tm and six equivalent Ag atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm2Zn17 by Materials Project

Tm2Zn17 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Tm is bonded in a 10-coordinate geometry to nineteen Zn atoms. There are a spread of Tm–Zn bond distances ranging from 3.09–3.45 Å. There are four inequivalent Zn sites. In the first Zn site, Zn is bonded to three equivalent Tm and nine Zn atoms to form distorted ZnTm3Zn9 cuboctahedra that share corners with twenty-three ZnTm2Zn10 cuboctahedra, edges with ten ZnTm2Zn10 cuboctahedra, and faces with twenty ZnTm3Zn9 cuboctahedra. There are a spread of Zn–Zn bond distances ranging from 2.53–2.86 Å. In the second Zn site, Zn is bonded in a 2-coordinate geometry to one Tm and thirteen Zn atoms. There are a spread of Zn–Zn bond distances ranging from 2.65–2.98 Å. In the third Zn site, Zn is bonded to two equivalent Tm and ten Zn atoms to form ZnTm2Zn10 cuboctahedra that share corners with twenty-two ZnTm2Zn10 cuboctahedra, edges with ten ZnTm2Zn10 cuboctahedra, and faces with eighteen ZnTm3Zn9 cuboctahedra. All Zn–Zn bond lengths are 2.59 Å. In the fourth Zn site, Zn is bonded to two equivalent Tm and ten Zn atoms to form distorted ZnTm2Zn10 cuboctahedra that share corners with twenty-four ZnTm2Zn10 cuboctahedra, edges with five ZnTm2Zn10 cuboctahedra, and faces with twenty-one ZnTm3Zn9 cuboctahedra. Both Zn–Zn bond lengths are 2.67 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm2Ga8Fe by Materials Project

Tm2FeGa8 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Tm is bonded to twelve Ga atoms to form TmGa12 cuboctahedra that share corners with eight equivalent TmGa12 cuboctahedra, edges with eight equivalent GaTm4Ga8 cuboctahedra, faces with four equivalent GaTm4Ga8 cuboctahedra, and faces with five equivalent TmGa12 cuboctahedra. There are a spread of Tm–Ga bond distances ranging from 2.98–3.02 Å. Fe is bonded in a body-centered cubic geometry to eight Ga atoms. All Fe–Ga bond lengths are 2.47 Å. There are four inequivalent Ga sites. In the first Ga site, Ga is bonded in a 11-coordinate geometry to two equivalent Tm, two equivalent Fe, and seven Ga atoms. There are a spread of Ga–Ga bond distances ranging from 2.58–2.98 Å. In the second Ga site, Ga is bonded in a distorted rectangular see-saw-like geometry to four equivalent Tm and eight Ga atoms. There are two shorter (2.96 Å) and four longer (3.06 Å) Ga–Ga bond lengths. In the third Ga site, Ga is bonded in a 11-coordinate geometry to two equivalent Tm, two equivalent Fe, and seven Ga atoms. The Ga–Ga bond length is 2.58 Å. In the fourth Ga site, Ga is bonded to four equivalent Tm and eight Ga atoms to form distorted GaTm4Ga8 cuboctahedra that share corners with four equivalent GaTm4Ga8 cuboctahedra, edges with eight equivalent TmGa12 cuboctahedra, faces with four equivalent TmGa12 cuboctahedra, and faces with eight equivalent GaTm4Ga8 cuboctahedra. All Ga–Ga bond lengths are 2.98 Å.

36 MATERIALS SCIENCE↗
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 TmAl2 by Materials Project

TmAl2 is Cubic Laves structured and crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Tm is bonded in a 12-coordinate geometry to four equivalent Tm and twelve equivalent Al atoms. All Tm–Tm bond lengths are 3.38 Å. All Tm–Al bond lengths are 3.23 Å. Al is bonded to six equivalent Tm and six equivalent Al atoms to form a mixture of edge, face, and corner-sharing AlTm6Al6 cuboctahedra. All Al–Al bond lengths are 2.76 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TmAlCu by Materials Project

TmCuAl crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Tm is bonded in a 5-coordinate geometry to five Cu and six equivalent Al atoms. There are four shorter (2.88 Å) and one longer (2.90 Å) Tm–Cu bond lengths. There are two shorter (3.12 Å) and four longer (3.19 Å) Tm–Al bond lengths. There are two inequivalent Cu sites. In the first Cu site, Cu is bonded in a 9-coordinate geometry to three equivalent Tm and six equivalent Al atoms. All Cu–Al bond lengths are 2.57 Å. In the second Cu site, Cu is bonded in a 9-coordinate geometry to six equivalent Tm and three equivalent Al atoms. All Cu–Al bond lengths are 2.73 Å. Al is bonded in a 12-coordinate geometry to six equivalent Tm, four Cu, and two equivalent Al atoms. Both Al–Al bond lengths are 2.88 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TmFeGe2 by Materials Project

TmFeGe2 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Tm is bonded in a 6-coordinate geometry to four equivalent Fe and ten Ge atoms. All Tm–Fe bond lengths are 3.13 Å. There are a spread of Tm–Ge bond distances ranging from 3.08–3.28 Å. Fe is bonded in a 5-coordinate geometry to four equivalent Tm and five Ge atoms. There are one shorter (2.25 Å) and four longer (2.38 Å) Fe–Ge bond lengths. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a 1-coordinate geometry to six equivalent Tm, one Fe, and two equivalent Ge atoms. Both Ge–Ge bond lengths are 2.56 Å. In the second Ge site, Ge is bonded in a 4-coordinate geometry to four equivalent Tm and four equivalent Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm3Lu by Materials Project

LuTm3 is Magnesium-derived structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Lu is bonded to twelve equivalent Tm atoms to form LuTm12 cuboctahedra that share corners with six equivalent LuTm12 cuboctahedra, corners with twelve equivalent TmTm8Lu4 cuboctahedra, edges with eighteen equivalent TmTm8Lu4 cuboctahedra, faces with eight equivalent LuTm12 cuboctahedra, and faces with twelve equivalent TmTm8Lu4 cuboctahedra. There are six shorter (3.44 Å) and six longer (3.55 Å) Lu–Tm bond lengths. Tm is bonded to four equivalent Lu and eight equivalent Tm atoms to form TmTm8Lu4 cuboctahedra that share corners with four equivalent LuTm12 cuboctahedra, corners with fourteen equivalent TmTm8Lu4 cuboctahedra, edges with six equivalent LuTm12 cuboctahedra, edges with twelve equivalent TmTm8Lu4 cuboctahedra, faces with four equivalent LuTm12 cuboctahedra, and faces with sixteen equivalent TmTm8Lu4 cuboctahedra. There are four shorter (3.44 Å) and four longer (3.55 Å) Tm–Tm bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NdTm3 by Materials Project

Tm3Nd is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Tm is bonded to eight equivalent Tm and four equivalent Nd atoms to form TmNd4Tm8 cuboctahedra that share corners with twelve equivalent TmNd4Tm8 cuboctahedra, edges with eight equivalent NdTm12 cuboctahedra, edges with sixteen equivalent TmNd4Tm8 cuboctahedra, faces with four equivalent NdTm12 cuboctahedra, and faces with fourteen equivalent TmNd4Tm8 cuboctahedra. All Tm–Tm bond lengths are 3.54 Å. All Tm–Nd bond lengths are 3.54 Å. Nd is bonded to twelve equivalent Tm atoms to form NdTm12 cuboctahedra that share corners with twelve equivalent NdTm12 cuboctahedra, edges with twenty-four equivalent TmNd4Tm8 cuboctahedra, faces with six equivalent NdTm12 cuboctahedra, and faces with twelve equivalent TmNd4Tm8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KTm by Materials Project

KTm is alpha Samarium-derived structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. K is bonded to six equivalent K and six equivalent Tm atoms to form KK6Tm6 cuboctahedra that share corners with eighteen equivalent KK6Tm6 cuboctahedra, edges with six equivalent KK6Tm6 cuboctahedra, edges with twelve equivalent TmK6Tm6 cuboctahedra, faces with eight equivalent KK6Tm6 cuboctahedra, and faces with twelve equivalent TmK6Tm6 cuboctahedra. All K–K bond lengths are 3.60 Å. All K–Tm bond lengths are 4.14 Å. Tm is bonded to six equivalent K and six equivalent Tm atoms to form TmK6Tm6 cuboctahedra that share corners with eighteen equivalent TmK6Tm6 cuboctahedra, edges with six equivalent TmK6Tm6 cuboctahedra, edges with twelve equivalent KK6Tm6 cuboctahedra, faces with eight equivalent TmK6Tm6 cuboctahedra, and faces with twelve equivalent KK6Tm6 cuboctahedra. All Tm–Tm bond lengths are 3.60 Å.

36 MATERIALS SCIENCE↗