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At least 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Sr(TbS2)2 by Materials Project

Sr(TbS2)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Sr2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Sr–S bond distances ranging from 3.10–3.32 Å. There are two inequivalent Tb3+ sites. In the first Tb3+ site, Tb3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing TbS6 octahedra. The corner-sharing octahedra tilt angles range from 48–64°. There are a spread of Tb–S bond distances ranging from 2.73–2.79 Å. In the second Tb3+ site, Tb3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing TbS6 octahedra. The corner-sharing octahedra tilt angles range from 48–64°. There are a spread of Tb–S bond distances ranging from 2.70–2.80 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Sr2+ and three Tb3+ atoms. In the second S2- site, S2- is bonded to two equivalent Sr2+ and three equivalent Tb3+ atoms to form distorted edge-sharing SSr2Tb3 square pyramids. In the third S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Sr2+ and three Tb3+ atoms. In the fourth S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Sr2+ and three equivalent Tb3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr(B2Pt3)2 by Materials Project

Sr(Pt3B2)2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Sr2+ is bonded to twelve equivalent Pt+1.33- atoms to form edge-sharing SrPt12 cuboctahedra. All Sr–Pt bond lengths are 3.36 Å. Pt+1.33- is bonded in a 4-coordinate geometry to two equivalent Sr2+ and four B+1.50+ atoms. There are a spread of Pt–B bond distances ranging from 2.18–2.35 Å. There are two inequivalent B+1.50+ sites. In the first B+1.50+ site, B+1.50+ is bonded in a 6-coordinate geometry to six equivalent Pt+1.33- atoms. In the second B+1.50+ site, B+1.50+ is bonded in a 6-coordinate geometry to six equivalent Pt+1.33- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr(FeS2)2 by Materials Project

Sr(FeS2)2 crystallizes in the tetragonal I422 space group. The structure is three-dimensional. Sr2+ is bonded in a 8-coordinate geometry to eight equivalent S2- atoms. All Sr–S bond lengths are 3.13 Å. Fe3+ is bonded to four equivalent S2- atoms to form edge-sharing FeS4 tetrahedra. All Fe–S bond lengths are 2.15 Å. S2- is bonded in a 4-coordinate geometry to two equivalent Sr2+ and two equivalent Fe3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr(LuSe2)2 by Materials Project

Sr(LuSe2)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Sr2+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Sr–Se bond distances ranging from 3.19–3.44 Å. There are two inequivalent Lu3+ sites. In the first Lu3+ site, Lu3+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing LuSe6 octahedra. The corner-sharing octahedra tilt angles range from 48–61°. There are a spread of Lu–Se bond distances ranging from 2.79–2.86 Å. In the second Lu3+ site, Lu3+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing LuSe6 octahedra. The corner-sharing octahedra tilt angles range from 48–61°. There are a spread of Lu–Se bond distances ranging from 2.77–2.86 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Sr2+ and three Lu3+ atoms. In the second Se2- site, Se2- is bonded to two equivalent Sr2+ and three equivalent Lu3+ atoms to form a mixture of distorted edge and corner-sharing SeSr2Lu3 square pyramids. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Sr2+ and three Lu3+ atoms. In the fourth Se2- site, Se2- is bonded to two equivalent Sr2+ and three equivalent Lu3+ atoms to form a mixture of distorted edge and corner-sharing SeSr2Lu3 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr(YbS2)2 by Materials Project

Sr(YbS2)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Sr2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Sr–S bond distances ranging from 2.96–3.20 Å. There are two inequivalent Yb3+ sites. In the first Yb3+ site, Yb3+ is bonded to six S2- atoms to form YbS6 octahedra that share corners with four equivalent YbS5 square pyramids and edges with four equivalent YbS6 octahedra. There are a spread of Yb–S bond distances ranging from 2.70–3.01 Å. In the second Yb3+ site, Yb3+ is bonded to five S2- atoms to form distorted YbS5 square pyramids that share corners with four equivalent YbS6 octahedra and edges with two equivalent YbS5 square pyramids. The corner-sharing octahedra tilt angles range from 53–70°. There are a spread of Yb–S bond distances ranging from 2.63–3.04 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent Sr2+ and three Yb3+ atoms to form distorted edge-sharing SSr2Yb3 square pyramids. In the second S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Sr2+, two equivalent Yb3+, and one S2- atom. The S–S bond length is 2.14 Å. In the third S2- site, S2- is bonded to two equivalent Sr2+ and three Yb3+ atoms to form a mixture of distorted edge and corner-sharing SSr2Yb3 trigonal bipyramids. In the fourth S2- site, S2- is bonded in a 6-coordinate geometry to two equivalent Sr2+, three equivalent Yb3+, and one S2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr(SiPt)2 by Materials Project

Sr(PtSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Sr2+ is bonded in a distorted body-centered cubic geometry to eight equivalent Si4- atoms. All Sr–Si bond lengths are 3.31 Å. Pt3+ is bonded to four equivalent Si4- atoms to form a mixture of edge and corner-sharing PtSi4 tetrahedra. All Pt–Si bond lengths are 2.49 Å. Si4- is bonded in a 9-coordinate geometry to four equivalent Sr2+, four equivalent Pt3+, and one Si4- atom. The Si–Si bond length is 2.59 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr(ErSe2)2 by Materials Project

Sr(ErSe2)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Sr2+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Sr–Se bond distances ranging from 3.21–3.45 Å. There are two inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing ErSe6 octahedra. The corner-sharing octahedra tilt angles range from 48–63°. There are a spread of Er–Se bond distances ranging from 2.82–2.88 Å. In the second Er3+ site, Er3+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing ErSe6 octahedra. The corner-sharing octahedra tilt angles range from 48–63°. There are a spread of Er–Se bond distances ranging from 2.80–2.89 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Sr2+ and three Er3+ atoms. In the second Se2- site, Se2- is bonded to two equivalent Sr2+ and three equivalent Er3+ atoms to form a mixture of distorted corner and edge-sharing SeSr2Er3 square pyramids. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Sr2+ and three Er3+ atoms. In the fourth Se2- site, Se2- is bonded to two equivalent Sr2+ and three equivalent Er3+ atoms to form a mixture of distorted corner and edge-sharing SeSr2Er3 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr(CO2)3 by Materials Project

Sr(CO2)3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.57–2.84 Å. There are three inequivalent C+3.33+ sites. In the first C+3.33+ site, C+3.33+ is bonded in a bent 150 degrees geometry to two O2- atoms. There is one shorter (1.22 Å) and one longer (1.23 Å) C–O bond length. In the second C+3.33+ site, C+3.33+ is bonded in a bent 150 degrees geometry to two O2- atoms. There is one shorter (1.21 Å) and one longer (1.23 Å) C–O bond length. In the third C+3.33+ site, C+3.33+ is bonded in a bent 120 degrees geometry to two O2- atoms. Both C–O bond lengths are 1.27 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Sr2+ and one C+3.33+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+3.33+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Sr2+ and one C+3.33+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Sr2+ and one C+3.33+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one Sr2+ and one C+3.33+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Sr2+ and one C+3.33+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr(BrO3)2 by Materials Project

Sr(O3Br)2 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. Sr2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Sr–O bond distances ranging from 2.49–2.81 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Sr2+ and one Br5+ atom. The O–Br bond length is 1.75 Å. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Br5+ atoms. Both O–Br bond lengths are 2.00 Å. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Sr2+ and one Br5+ atom. The O–Br bond length is 1.67 Å. In the fourth O2- site, O2- is bonded in a trigonal planar geometry to one Sr2+ and two equivalent Br5+ atoms. Both O–Br bond lengths are 2.11 Å. Br5+ is bonded in a rectangular see-saw-like geometry to four O2- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr(ErS2)2 by Materials Project

Sr(ErS2)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Sr2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Sr–S bond distances ranging from 3.09–3.32 Å. There are two inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing ErS6 octahedra. The corner-sharing octahedra tilt angles range from 48–64°. There are a spread of Er–S bond distances ranging from 2.69–2.74 Å. In the second Er3+ site, Er3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing ErS6 octahedra. The corner-sharing octahedra tilt angles range from 48–64°. There are a spread of Er–S bond distances ranging from 2.67–2.76 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Sr2+ and three Er3+ atoms. In the second S2- site, S2- is bonded to two equivalent Sr2+ and three equivalent Er3+ atoms to form a mixture of distorted edge and corner-sharing SSr2Er3 square pyramids. In the third S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Sr2+ and three Er3+ atoms. In the fourth S2- site, S2- is bonded to two equivalent Sr2+ and three equivalent Er3+ atoms to form a mixture of distorted edge and corner-sharing SSr2Er3 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr(NiP2)2 by Materials Project

Sr(NiP2)2 crystallizes in the orthorhombic Fddd space group. The structure is three-dimensional. Sr2+ is bonded to eight equivalent P1- atoms to form distorted SrP8 hexagonal bipyramids that share corners with sixteen equivalent NiP4 tetrahedra and edges with four equivalent SrP8 hexagonal bipyramids. There are four shorter (3.12 Å) and four longer (3.14 Å) Sr–P bond lengths. Ni1+ is bonded to four equivalent P1- atoms to form NiP4 tetrahedra that share corners with eight equivalent SrP8 hexagonal bipyramids and edges with two equivalent NiP4 tetrahedra. There are two shorter (2.21 Å) and two longer (2.22 Å) Ni–P bond lengths. P1- is bonded in a 6-coordinate geometry to two equivalent Sr2+, two equivalent Ni1+, and two equivalent P1- atoms. There are one shorter (2.23 Å) and one longer (2.25 Å) P–P bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr(SbRu)2 by Materials Project

Sr(RuSb)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Sr2+ is bonded in a body-centered cubic geometry to eight equivalent Sb3- atoms. All Sr–Sb bond lengths are 3.54 Å. Ru2+ is bonded to four equivalent Sb3- atoms to form a mixture of edge and corner-sharing RuSb4 tetrahedra. All Ru–Sb bond lengths are 2.60 Å. Sb3- is bonded in a 9-coordinate geometry to four equivalent Sr2+, four equivalent Ru2+, and one Sb3- atom. The Sb–Sb bond length is 3.12 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr(RuO3)2 by Materials Project

Sr(RuO3)2 is Hydrophilite-derived structured and crystallizes in the trigonal P-31m space group. The structure is three-dimensional. Sr2+ is bonded to six equivalent O2- atoms to form SrO6 octahedra that share corners with twelve equivalent RuO6 octahedra. The corner-sharing octahedral tilt angles are 54°. All Sr–O bond lengths are 2.57 Å. Ru5+ is bonded to six equivalent O2- atoms to form RuO6 octahedra that share corners with six equivalent SrO6 octahedra and edges with three equivalent RuO6 octahedra. The corner-sharing octahedral tilt angles are 54°. All Ru–O bond lengths are 1.96 Å. O2- is bonded in a distorted trigonal planar geometry to one Sr2+ and two equivalent Ru5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr(HoS2)2 by Materials Project

Sr(HoS2)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Sr2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Sr–S bond distances ranging from 3.09–3.29 Å. There are two inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing HoS6 octahedra. The corner-sharing octahedra tilt angles range from 48–63°. There are a spread of Ho–S bond distances ranging from 2.70–2.76 Å. In the second Ho3+ site, Ho3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing HoS6 octahedra. The corner-sharing octahedra tilt angles range from 48–63°. There are a spread of Ho–S bond distances ranging from 2.68–2.76 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Sr2+ and three Ho3+ atoms. In the second S2- site, S2- is bonded to two equivalent Sr2+ and three equivalent Ho3+ atoms to form a mixture of distorted edge and corner-sharing SSr2Ho3 square pyramids. In the third S2- site, S2- is bonded to two equivalent Sr2+ and three Ho3+ atoms to form a mixture of distorted edge and corner-sharing SSr2Ho3 trigonal bipyramids. In the fourth S2- site, S2- is bonded to two equivalent Sr2+ and three equivalent Ho3+ atoms to form a mixture of distorted edge and corner-sharing SSr2Ho3 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Am-241, Pu-238, Pu-239/240, and Sr-90 Decision Levels for the Environmental Air Monitoring Program for the Idaho National Laboratory

This report provides a comprehensive analysis of Am-241, Pu-238, Pu-239/240, and Sr-90 radiation data collected from air monitoring sites at or near Idaho National Laboratory from June 2013 through December 2020. These data were used to compute monitoring limits that will be used to assess future measurements of Am-241, Pu-238, Pu-239/240, and Sr-90. Data were analyzed for seasonality, stationarity, and other data issues that may impact the calculation and use of the monitoring limits.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Sr and Co Vapor-Phase Transport from LSCF Cathodes

A series of tests were performed to differentiate between surface diffusion and vapor-phase diffusion of chemical species from LSCF cathode material at typical sintering temperatures (up to 1100°C) in SOFC production. A GDC source substrate was printed with LSCF and separated by an air gap from a YSZ target substrate. Various geometries with long surface paths were employed to reduce the possibility of surface transport. Sr and Co were detected on the target substrates via energy dispersive spectroscopy (EDS) and x-ray photoelectron spectroscopy (XPS), including spatially resolved XPS. These results support a vapor-phase transport mechanism for Sr and Co. Sintering conditions and barrier layer requirements may need to be revisited to prevent the formation of undesired strontium zirconate at cathode/electrolyte interface due to vapor-phase transport.

vapor phase transport, SOFC cathode, Sr transport↗
DOE OSTI2023

Resolving Diverse Oxygen Transport Pathways Across Sr‐Doped Lanthanum Ferrite and Metal‐Perovskite Heterostructures

Abstract Perovskite structured transition metal oxides are important technological materials for catalysis and solid oxide fuel cell applications. Their functionality often depends on oxygen diffusivity and mobility through complex oxide heterostructures, which can be significantly impacted by structural and chemical modifications, such as doping. Further, when utilized within electrochemical cells, interfacial reactions with other components (e.g., Ni‐ and Cr‐based alloy electrodes and interconnects) can influence the perovskite's reactivity and ion transport, leading to complex dependencies that are difficult to control in real‐world environments. Here, this work uses isotopic tracers and atom probe tomography to directly visualize oxygen diffusion and transport pathways across perovskite and metal‐perovskite heterostructures, that is, (Ni‐Cr coated) Sr‐doped lanthanum ferrite (La 0.5 Sr 0.5 FeO 3 ; LSFO). Annealing in 18 O 2(g) results in elemental and isotopic redistributions through oxygen exchange (OE) in the LSFO while Ni‐Cr undergoes oxidation via multiple mechanisms and transport pathways. Complementary density functional theory calculations at experimental conditions provide rationale for OE reaction mechanisms and reveal a complex interplay of different thermodynamic and kinetic drivers. These results shed light on the fundamental coupling of defects and oxygen transport in an important class of catalytic materials.

36 MATERIALS SCIENCE↗
DOE OSTI2022

(La 0.8 Sr 0.2 ) 0.98 MnO 3-δ -Zr 0.92 Y 0.16 O 2-δ :PrOx for oxygen electrode supported solid oxide cells

(La 0.8 Sr 0.2 ) 0.98 MnO 3-δ (LSM)- Zr 0.92 Y 0.16 O 2-δ (YSZ) has been widely studied as the cathode for solid oxide fuel cells (SOFCs), but its low activity has been a cell performance limiting factor. Herein, LSM-YSZ:PrO x composite is developed as an active electrocatalyst for both oxygen reduction and evolution reactions. A single step PrO x infiltration into LSM-YSZ lowers the polarization resistance (Rp) 10–20 times depending on the test temperature. Distribution of relaxation times (DRT) calculation reveals that adding PrO x affects surface exchange between adsorbed/desorbed oxygen and lattice oxygen, and oxygen dissociative adsorption/desorption. A symmetrical cell with a thin YSZ electrolyte sandwiched between thick LSM-YSZ:PrO x electrode-supports is developed and its oxygen generation performance and stability are evaluated under various current densities and temperatures. Finally, reversible solid oxide cell (ReSOC) performance is also reported for LSM-YSZ:PrO x supported cells with the oxide fuel electrode Sr 0.95 (Ti 0.3 Fe 0.63 Ni 0.07 )O 3-δ (STFN).

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗