Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Sm”

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 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Sm(FeO2)2 by Materials Project

Sm(FeO2)2 is Aluminum carbonitride-like structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. Sm3+ is bonded to six O2- atoms to form distorted SmO6 octahedra that share corners with six FeO5 trigonal bipyramids and edges with six equivalent SmO6 octahedra. There are three shorter (2.33 Å) and three longer (2.36 Å) Sm–O bond lengths. There are two inequivalent Fe+2.50+ sites. In the first Fe+2.50+ site, Fe+2.50+ is bonded to five O2- atoms to form FeO5 trigonal bipyramids that share corners with three equivalent SmO6 octahedra, corners with six equivalent FeO5 trigonal bipyramids, and edges with three equivalent FeO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 62–65°. There are a spread of Fe–O bond distances ranging from 2.04–2.26 Å. In the second Fe+2.50+ site, Fe+2.50+ is bonded to five O2- atoms to form FeO5 trigonal bipyramids that share corners with three equivalent SmO6 octahedra, corners with six equivalent FeO5 trigonal bipyramids, and edges with three equivalent FeO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 61–63°. There are a spread of Fe–O bond distances ranging from 1.93–2.12 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to four Fe+2.50+ atoms to form OFe4 trigonal pyramids that share corners with four OSm3Fe tetrahedra, corners with six equivalent OFe4 trigonal pyramids, and edges with three equivalent OFe4 trigonal pyramids. In the second O2- site, O2- is bonded to three equivalent Sm3+ and one Fe+2.50+ atom to form OSm3Fe tetrahedra that share corners with nine OSm3Fe tetrahedra, corners with four OFe4 trigonal pyramids, and edges with three equivalent OSm3Fe tetrahedra. In the third O2- site, O2- is bonded to three equivalent Sm3+ and one Fe+2.50+ atom to form distorted OSm3Fe tetrahedra that share corners with nine OSm3Fe tetrahedra, corners with four OFe4 trigonal pyramids, and edges with three equivalent OSm3Fe tetrahedra. In the fourth O2- site, O2- is bonded to four Fe+2.50+ atoms to form OFe4 trigonal pyramids that share corners with four OSm3Fe tetrahedra, corners with six equivalent OFe4 trigonal pyramids, and edges with three equivalent OFe4 trigonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sm(CuO2)2 by Materials Project

Sm(CuO2)2 crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. Sm3+ is bonded in a 8-coordinate geometry to eight equivalent O2- atoms. There are four shorter (2.44 Å) and four longer (2.45 Å) Sm–O bond lengths. Cu+2.50+ is bonded in a square co-planar geometry to four equivalent O2- atoms. There is two shorter (1.90 Å) and two longer (1.92 Å) Cu–O bond length. O2- is bonded to two equivalent Sm3+ and two equivalent Cu+2.50+ atoms to form a mixture of distorted corner and edge-sharing OSm2Cu2 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sm(CrB3)2 by Materials Project

Sm(CrB3)2 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Sm2+ is bonded in a 12-coordinate geometry to sixteen B1- atoms. There are a spread of Sm–B bond distances ranging from 2.81–2.96 Å. Cr2+ is bonded in a 10-coordinate geometry to ten B1- atoms. There are a spread of Cr–B bond distances ranging from 2.12–2.22 Å. There are two inequivalent B1- sites. In the first B1- site, B1- is bonded in a 6-coordinate geometry to three equivalent Sm2+, three equivalent Cr2+, and three B1- atoms. There is one shorter (1.76 Å) and two longer (1.79 Å) B–B bond length. In the second B1- site, B1- is bonded in a 9-coordinate geometry to two equivalent Sm2+, four equivalent Cr2+, and three B1- atoms. The B–B bond length is 1.84 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sm(Ni2B)6 by Materials Project

Sm(Ni2B)6 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. Sm2+ is bonded in a distorted hexagonal planar geometry to six B3- atoms. There are a spread of Sm–B bond distances ranging from 3.01–3.28 Å. There are seven inequivalent Ni+1.33+ sites. In the first Ni+1.33+ site, Ni+1.33+ is bonded in a distorted T-shaped geometry to three B3- atoms. There are two shorter (2.10 Å) and one longer (2.18 Å) Ni–B bond lengths. In the second Ni+1.33+ site, Ni+1.33+ is bonded in a T-shaped geometry to three B3- atoms. There are two shorter (2.00 Å) and one longer (2.08 Å) Ni–B bond lengths. In the third Ni+1.33+ site, Ni+1.33+ is bonded to four B3- atoms to form a mixture of corner and edge-sharing NiB4 tetrahedra. There are a spread of Ni–B bond distances ranging from 1.99–2.10 Å. In the fourth Ni+1.33+ site, Ni+1.33+ is bonded in a T-shaped geometry to three B3- atoms. There are a spread of Ni–B bond distances ranging from 2.02–2.11 Å. In the fifth Ni+1.33+ site, Ni+1.33+ is bonded to four B3- atoms to form a mixture of corner and edge-sharing NiB4 tetrahedra. There are a spread of Ni–B bond distances ranging from 2.02–2.10 Å. In the sixth Ni+1.33+ site, Ni+1.33+ is bonded to four B3- atoms to form a mixture of distorted corner and edge-sharing NiB4 tetrahedra. There are a spread of Ni–B bond distances ranging from 2.02–2.11 Å. In the seventh Ni+1.33+ site, Ni+1.33+ is bonded in a distorted T-shaped geometry to three B3- atoms. There are a spread of Ni–B bond distances ranging from 2.06–2.14 Å. There are four inequivalent B3- sites. In the first B3- site, B3- is bonded in a 7-coordinate geometry to one Sm2+ and seven Ni+1.33+ atoms. In the second B3- site, B3- is bonded in a 7-coordinate geometry to one Sm2+ and seven Ni+1.33+ atoms. In the third B3- site, B3- is bonded in a 7-coordinate geometry to one Sm2+ and seven Ni+1.33+ atoms. In the fourth B3- site, B3- is bonded in a 7-coordinate geometry to one Sm2+ and seven Ni+1.33+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sm(NiSb)2 by Materials Project

Sm(NiSb)2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Sm2+ is bonded in a 8-coordinate geometry to eight Sb3- atoms. There are four shorter (3.34 Å) and four longer (3.44 Å) Sm–Sb bond lengths. There are two inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to four equivalent Sb3- atoms to form a mixture of edge and corner-sharing NiSb4 tetrahedra. All Ni–Sb bond lengths are 2.56 Å. In the second Ni2+ site, Ni2+ is bonded in a 5-coordinate geometry to five Sb3- atoms. There are one shorter (2.51 Å) and four longer (2.55 Å) Ni–Sb bond lengths. There are two inequivalent Sb3- sites. In the first Sb3- site, Sb3- is bonded in a 4-coordinate geometry to four equivalent Sm2+ and four equivalent Ni2+ atoms. In the second Sb3- site, Sb3- is bonded in a 9-coordinate geometry to four equivalent Sm2+ and five Ni2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sm(NiAs)2 by Materials Project

Sm(NiAs)2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Sm2+ is bonded in a 8-coordinate geometry to eight As3- atoms. There are four shorter (3.16 Å) and four longer (3.17 Å) Sm–As bond lengths. There are two inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to four equivalent As3- atoms to form a mixture of edge and corner-sharing NiAs4 tetrahedra. All Ni–As bond lengths are 2.42 Å. In the second Ni2+ site, Ni2+ is bonded in a 5-coordinate geometry to five As3- atoms. There are one shorter (2.35 Å) and four longer (2.39 Å) Ni–As bond lengths. There are two inequivalent As3- sites. In the first As3- site, As3- is bonded in a 4-coordinate geometry to four equivalent Sm2+ and four equivalent Ni2+ atoms. In the second As3- site, As3- is bonded in a 9-coordinate geometry to four equivalent Sm2+ and five Ni2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sm(NiB)2 by Materials Project

Sm(NiB)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Sm2+ is bonded in a 2-coordinate geometry to six equivalent B3- atoms. There are a spread of Sm–B bond distances ranging from 2.73–2.90 Å. Ni2+ is bonded in a 4-coordinate geometry to four equivalent B3- atoms. There are a spread of Ni–B bond distances ranging from 2.04–2.07 Å. B3- is bonded in a 8-coordinate geometry to three equivalent Sm2+, four equivalent Ni2+, and one B3- atom. The B–B bond length is 1.74 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sm(CuTe)3 by Materials Project

Sm(CuTe)3 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. Sm3+ is bonded to six equivalent Te2- atoms to form SmTe6 octahedra that share corners with twelve equivalent CuTe4 tetrahedra, edges with three equivalent SmTe6 octahedra, and edges with six equivalent CuTe4 tetrahedra. All Sm–Te bond lengths are 3.12 Å. Cu1+ is bonded to four equivalent Te2- atoms to form CuTe4 tetrahedra that share corners with four equivalent SmTe6 octahedra, corners with six equivalent CuTe4 tetrahedra, edges with two equivalent SmTe6 octahedra, and edges with three equivalent CuTe4 tetrahedra. The corner-sharing octahedra tilt angles range from 18–57°. There are a spread of Cu–Te bond distances ranging from 2.61–2.67 Å. Te2- is bonded in a 6-coordinate geometry to two equivalent Sm3+ and four equivalent Cu1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sm(PPd)2 by Materials Project

Sm(PdP)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Sm2+ is bonded to eight equivalent P3- atoms to form SmP8 hexagonal bipyramids that share corners with sixteen equivalent PdP4 tetrahedra, edges with four equivalent SmP8 hexagonal bipyramids, edges with eight equivalent PdP4 tetrahedra, and faces with four equivalent SmP8 hexagonal bipyramids. All Sm–P bond lengths are 3.13 Å. Pd2+ is bonded to four equivalent P3- atoms to form PdP4 tetrahedra that share corners with eight equivalent SmP8 hexagonal bipyramids, corners with four equivalent PdP4 tetrahedra, edges with four equivalent SmP8 hexagonal bipyramids, and edges with four equivalent PdP4 tetrahedra. All Pd–P bond lengths are 2.48 Å. P3- is bonded in a 9-coordinate geometry to four equivalent Sm2+, four equivalent Pd2+, and one P3- atom. The P–P bond length is 2.23 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sm(Mo3Se4)2 by Materials Project

Sm(Mo3Se4)2 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. Sm3+ is bonded in a body-centered cubic geometry to eight Se2- atoms. There are two shorter (2.87 Å) and six longer (3.14 Å) Sm–Se bond lengths. Mo+2.17+ is bonded to five Se2- atoms to form a mixture of corner and edge-sharing MoSe5 square pyramids. There are a spread of Mo–Se bond distances ranging from 2.53–2.77 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 1-coordinate geometry to one Sm3+ and three equivalent Mo+2.17+ atoms. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to one Sm3+ and four equivalent Mo+2.17+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sm(PO3)3 by Materials Project

Sm(PO3)3 crystallizes in the orthorhombic C222_1 space group. The structure is three-dimensional. Sm3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sm–O bond distances ranging from 2.36–2.69 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.62 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There is two shorter (1.52 Å) and two longer (1.59 Å) P–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Sm3+ and one P5+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent P5+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to one Sm3+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Sm3+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Overcoming mechanical fragility in Sm-Co permanent magnet materials

Samarium-cobalt alloys are used in some of the strongest permanent magnets, particularly for applications between about 200 and 550°C, but the utilization of these materials is restricted by their brittleness. Improving their mechanical resilience would allow them to be used more widely and, in some cases, substitute for neodymium-based magnet alloys which are subject to supply-chain risks. In this work, we have engineered a series of novel microstructures with bi-modal grain size distributions to achieve unprecedented combinations of mechanical and magnetic properties. Improvements up to 73% are obtained in the flexural strength of Sm 2 (CoFeCuZr) 17 sintered magnets, with negligible impact on the magnetic properties. Our mechanically-robust, high-performance Sm-Co magnets are made without changing the chemical compositions of the materials or their heat treatment procedures, making them highly compatible with existing manufacturing processes.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Toughening Sm–Co sintered magnets via microstructure modification with additives

We report the mechanical properties of the brittle Smsingle bondCo permanent magnets are of great practical significance. However, studies on the magnets have mostly focused on their magnetic properties. This paper reports the modified microstructure and refined unimodal grain size, enhanced flexural strength, and magnetic properties of Sm 2 (Co,Fe,Cu,Zr) 17 sintered magnets doped with La 2 O 3 , MgO, and CaF 2 fine particulates. The correlations between microstructure, phase composition, and mechanical and magnetic properties were studied. Doping of a small amount (e.g., 0.5–3 wt%) of La 2 O 3 , MgO, or CaF 2 fine particulates could significantly refine the unimodal grain sizes of the Smsingle bondCo magnets via the Zener pinning effect. Moreover, doping significantly improved the flexural strengths σ of the magnets. For example, the σ values of the magnets with 0.5 wt% MgO, 1 wt% La 2 O 3 , and 1 wt% CaF 2 were approximately 65%, 63%, and 42% higher than that of the reference magnet, respectively. Micromechanical simulations revealed that the fine particles of La 2 O 3 could deflect crack growth, while the CaF 2 particles could attract or arrest cracks during the fracture process. The mechanical strengthening effect was mainly due to grain size refinement. The Smsingle bondCo magnets with 0.5–1.5 wt% CaF2 and 0.5 wt% La 2 O 3 exhibited excellent magnetic properties while doping 1–3 wt% La2O3 and 0.5–3 wt% MgO deteriorated magnetic performance. The rational design of CaF 2 - or La 2 O 3 -doped microstructure can be an economical and effective method for producing toughened Sm–Co sintered magnets with high magnetic performance.

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 OSTI2023

Exceptional magnetic and magnetoelastic behavior of rare-earth non-centrosymmetric Sm 7 Pd 3

Magnetic compounds possessing an intrinsic combination of near-zero magnetization with high magnetic anisotropy are highly desirable for spinronic applications and memory recording. A comprehensive study of Sm 7 Pd 3 binary compound uncovered a unique combination of strong magnetoelastic behavior, very low net magnetization, and exceptionally high magnetic coercivity. The temperature-dependent X-ray synchrotron powder diffraction study indicates the abrupt changes in the compound's lattice parameters at the magnetic ordering temperature of T C =169 K, although the crystal structure remains non-centrosymmetric hexagonal Th 7 Fe 3 -type down to 6 K. Density functional theory calculations confirm high intrinsic magnetocrystalline anisotropy of Sm 7 Pd 3 , which explains the extremely large coercivity of the polycrystalline sample, up to H cr = 130 kOe at 2 K. In conclusion, this discovery brings to life a novel class of highly anisotropic materials that are distinctly different from known spintronic materials, making them interesting future systems for magnetic memory research.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Intrinsic and hard magnetic properties of (Sm 1-x R x )-Fe-Co-V alloys (R = Gd, Zr, and Y)

SmFe 12 -based compounds with the ThMn 12 -type structure have a great potential as future rare-earth-lean permanent magnets. However, their reliance on stabilizing non-magnetic elements has impeded practical applications. Therefore, elements such as Gd, Y, and Zr have gained popularity as candidates to minimize the need for stabilizing elements by reducing the formation energy of the ThMn 12 (1:12) phase. Here, this study examines the effect of Gd, Y, and Zr on the intrinsic and hard magnetic properties in (Sm 1-x R x ) 1.2 Fe 8.4 Co 2.1 V 1.5 (or with nominal composition of (Sm 1-x R x ) 9.1 Fe 63.6 Co 15.9 V 11.4 ) with a single 1:12 phase for 0 ≤ x ≤ 0.3. Notably, samples substituted with Gd exhibit an enhanced temperature dependence of the magnetic properties.

36 MATERIALS SCIENCE↗
DOE OSTI2020

High-pressure synthesis, crystal structure, and magnetic properties of the Shastry-Sutherland-lattice oxides BaL n 2 ZnO 5 (L n = Pr, Sm, Eu)

BaPr 2 ZnO 5 , BaSm 2 ZnO 5 , and BaEu 2 ZnO 5 – a series of 4f magnetic insulators comprising the Shastry-Sutherland lattice – were synthesized via a solid-state reaction under high-pressure and high-temperature conditions. The magnetic behaviors are well characterized by the localized 4f electrons of each Ln 3+ (= Pr, Sm, Eu) under the influence of the crystal-electric field of the surrounding ions. The magnetic susceptibility and heat capacity measurements of BaPr 2 ZnO 5 (Pr 3+ ; 4f 2 3 H 4 ) indicate the splitting of the ground state J-multiplet due to the crystal-electric field. BaSm 2 ZnO 5 (Sm 3+ ; 4f 5 6 H 5/2 ) is a strong Van Vleck paramagnet, while BaEu 2 ZnO 5 is non-magnetic due to the 7 F 0 ground state (Eu 3+ ; 4f 6 7 F 0 ). The series of new oxides enriches a group of the Shastry-Sutherland lattice materials and helps to develop a range of two-dimensional quantum materials.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Absolute decay counting of 146 Sm with 4π cryogenic microcalorimetry

We present a methodology for absolute activity counting of long-lived isotopes based on cryogenic Decay Energy Spectroscopy. A 146 Sm source was produced at the TRIUMF Laboratory and then processed and purified at Lawrence Livermore National Laboratory, yielding a pure sample. The source was embedded within a 4π thermal absorber coupled to a magnetic microcalorimeter achieving nearly 100% counting efficiency. Experimental uncertainties were studied and modeled, including thermal coupling of the source to the absorber, pulse pile-up, trigger, and event selection efficiencies. Here, the absolute activity of the pure 146 Sm source was measured to better than 1% uncertainty.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗