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At least 199 records · Page 11
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

Physical and mechanical properties of the B2 compound NiAl

Considerable work has been performed on NiAl over the last three decades, with an extremely rapid growth in research on this intermetallic occurring in the last few years due to recent interest in this material for electronic and high temperature structural applications. However, many physical properties and the controlling fracture and deformation mechanisms over certain temperature regimes are still in question. Part of this problem lies in the incomplete characterization of many of the alloys previously investigated. Fragmentary data on processing conditions, chemistry, microstructure and the apparent difficulty in accurately measuring composition has made direct comparison between individual studies sometimes tenuous. Therefore, the purpose of this review is to summarize all available mechanical and pertinent physical properties on NiAl, stressing the most recent investigations, in an attempt to understand the behavior of NiAl and its alloys over a broad temperature range.

Noebe, R. D.↗
NASA NTRS1995

Star formation in the Galactic Center GMC cores: Sagittarius B2 and the dust ridge

The total far-infrared luminosity and the ionizing flux inferred from radio continuum observations of the Galactic center region imply a rate of star formation per unit mass of molecular material comparable to that in the Galactic disk. However, H2O and OH masers commonly found in sites of high-mass star formation are relatively rare in the nuclear disk. Far-infrared studies suggest that the formation rate of stars with masses greater than approximately 20 Solar Mass is reduced in the central region compared to the Galactic disk. Star formation might be suppressed currently in the central region as a result of the different geometry and strength of the magnetic fields there, which arguably might tend to inhibit cloud collapse. High gas pressures implied by observations of the diffuse X-ray emission suggest that giant molecular clouds (GMCs) in the nuclear disk may be held together by external pressure rather than self-gravity. The gravitational collapse leading to the formation of high density cores may thus be suppressed in all but the most massive clouds.

Lis, D. C.↗
NASA NTRS2002

Modeling of the Site Preference in Ternary B2-Ordered Ni-Al-Fe Alloys

The underlying equilibrium structure, site substitution behavior, and lattice parameter of ternary Ni-Fe-Al alloys are determined via Monte Carlo-Metropolis computer simulations and analytical calculations using the BFS method for alloys for the energetics. As a result of the theoretical calculations presented, a simple approach based on the energetics of small atomic clusters is introduced to explain the observed site preference schemes.

Bozzolo, Guillermo H.↗
NASA NTRS1991

Creep Deformation of B2 Alumindes

The creep resistance and elevated temperature deformation mechanisms in CoAl, FeAl, and NiAl are reviewed. The stress and temperature dependencies of the steady state creep rate, the primary creep behavior, the dislocation substructure, and the response during transient tests are used as the main indicators of the deformation processes. In single phase intermetallics, the influence of grain size, stoichiometry, and solid solution hardening have been examined. In addition, the effect of adding dispersoids, precipitates, and other types of reinforcements to improve creep strength are compared.

Nathal, M. V.↗
NASA NTRS2015

Lightning Protection and Structural Bonding for the B2 Test Stand

With the privatization of the space industry, NASA has entered a new era. To explore deeper parts of the solar system, NASA is developing a new spacecraft, the Space Launch System (SLS), capable of reaching these destinations, such as an asteroid or Mars. However, the test stand that is capable of testing the stage has been unused for many years. In addition to the updating/repair of the stand, more steel is being added to fully support the SLS. With all these modifications, the lightning protection system must be brought up to code to assure the protection of all personnel and assets. Structural bonding is a part of the lightning protection system. The focus of this project was to assure proper structural bonding. To begin, all relevant technical standards and the construction specifications were reviewed. This included both the specifications for the lightning protection and for general construction. The drawings were reviewed as well. From the drawings, bolted structural joints were reviewed to determine whether bonding was necessary. Several bolted joints were determined to need bonding according to the notes in the drawings. This exceeds the industry standards. The bolted joints are an electrically continuous joint. During tests, the stand experiences heavy vibration that may weaken the continuity of the bolted joint. Therefore, the secondary bonding is implemented to ensure that the structural joint has low resistance. If the structural joint has a high resistance because of corrosion, a potential gradient can occur that can cause a side flash. Damage, injury, or death can occur from a side flash so they are to be prevented. A list of the identified structural joints was compiled and sent to the contractor to be bonded. That covers the scope of this project.

Kinard, Brandon↗
DOE OSTI2019

Materials Data on RbB6S2(Cl3O2)2 by Materials Project

Rb2B11S4O8Cl11BCl crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional and consists of four chloroborane molecules and one Rb2B11S4O8Cl11 framework. In the Rb2B11S4O8Cl11 framework, there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 10-coordinate geometry to four O2- and six Cl1- atoms. There are a spread of Rb–O bond distances ranging from 3.03–3.19 Å. There are a spread of Rb–Cl bond distances ranging from 3.46–3.98 Å. In the second Rb1+ site, Rb1+ is bonded in a 12-coordinate geometry to three O2- and nine Cl1- atoms. There are a spread of Rb–O bond distances ranging from 3.16–3.27 Å. There are a spread of Rb–Cl bond distances ranging from 3.52–3.94 Å. There are eleven inequivalent B2+ sites. In the first B2+ site, B2+ is bonded in a single-bond geometry to one Cl1- atom. The B–Cl bond length is 1.80 Å. In the second B2+ site, B2+ is bonded in a single-bond geometry to one Cl1- atom. The B–Cl bond length is 1.80 Å. In the third B2+ site, B2+ is bonded in a single-bond geometry to one Cl1- atom. The B–Cl bond length is 1.80 Å. In the fourth B2+ site, B2+ is bonded in a single-bond geometry to one Cl1- atom. The B–Cl bond length is 1.79 Å. In the fifth B2+ site, B2+ is bonded in a single-bond geometry to one Cl1- atom. The B–Cl bond length is 1.80 Å. In the sixth B2+ site, B2+ is bonded in a single-bond geometry to one Cl1- atom. The B–Cl bond length is 1.80 Å. In the seventh B2+ site, B2+ is bonded in a single-bond geometry to one Cl1- atom. The B–Cl bond length is 1.80 Å. In the eighth B2+ site, B2+ is bonded in a single-bond geometry to one Cl1- atom. The B–Cl bond length is 1.79 Å. In the ninth B2+ site, B2+ is bonded in a single-bond geometry to one Cl1- atom. The B–Cl bond length is 1.80 Å. In the tenth B2+ site, B2+ is bonded in a single-bond geometry to one Cl1- atom. The B–Cl bond length is 1.80 Å. In the eleventh B2+ site, B2+ is bonded in a single-bond geometry to one Cl1- atom. The B–Cl bond length is 1.80 Å. There are four inequivalent S+0.50+ sites. In the first S+0.50+ site, S+0.50+ is bonded in a bent 120 degrees geometry to two O2- atoms. Both S–O bond lengths are 1.45 Å. In the second S+0.50+ site, S+0.50+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.45 Å) and one longer (1.46 Å) S–O bond length. In the third S+0.50+ site, S+0.50+ is bonded in a bent 120 degrees geometry to two O2- atoms. Both S–O bond lengths are 1.45 Å. In the fourth S+0.50+ site, S+0.50+ is bonded in a bent 120 degrees geometry to two O2- atoms. Both S–O bond lengths are 1.45 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Rb1+ and one S+0.50+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Rb1+ and one S+0.50+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to one Rb1+ and one S+0.50+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one S+0.50+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one Rb1+ and one S+0.50+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to one Rb1+ and one S+0.50+ atom. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to one Rb1+ and one S+0.50+ atom. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to one Rb1+ and one S+0.50+ atom. There are eleven inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to two Rb1+ and one B2+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to two Rb1+ and one B2+ atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one Rb1+ and one B2+ atom. In the fourth Cl1- site, Cl1- is bonded in a single-bond geometry to one Rb1+ and one B2+ atom. In the fifth Cl1- site, Cl1- is bonded in a single-bond geometry to one Rb1+ and one B2+ atom. In the sixth Cl1- site, Cl1- is bonded in a single-bond geometry to one Rb1+ and one B2+ atom. In the seventh Cl1- site, Cl1- is bonded in a single-bond geometry to one Rb1+ and one B2+ atom. In the eighth Cl1- site, Cl1- is bonded in a single-bond geometry to one Rb1+ and one B2+ atom. In the ninth Cl1- site, Cl1- is bonded in a single-bond geometry to one Rb1+ and one B2+ atom. In the tenth Cl1- site, Cl1- is bonded in a distorted single-bond geometry to two Rb1+ and one B2+ atom. In the eleventh Cl1- site, Cl1- is bonded in a single-bond geometry to two Rb1+ and one B2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Be(B3H7)2 by Materials Project

BeB5H13BH is alpha carbon monoxide-like structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four boranediylradical molecules and four BeB5H13 clusters. In each BeB5H13 cluster, Be2+ is bonded in a 4-coordinate geometry to four H+0.71+ atoms. There are a spread of Be–H bond distances ranging from 1.53–1.59 Å. There are five inequivalent B2- sites. In the first B2- site, B2- is bonded in a distorted trigonal non-coplanar geometry to three H+0.71+ atoms. There are a spread of B–H bond distances ranging from 1.20–1.34 Å. In the second B2- site, B2- is bonded in a distorted trigonal non-coplanar geometry to three H+0.71+ atoms. There are a spread of B–H bond distances ranging from 1.19–1.35 Å. In the third B2- site, B2- is bonded in a distorted trigonal non-coplanar geometry to three H+0.71+ atoms. There are a spread of B–H bond distances ranging from 1.19–1.35 Å. In the fourth B2- site, B2- is bonded in a distorted trigonal non-coplanar geometry to three H+0.71+ atoms. There are a spread of B–H bond distances ranging from 1.20–1.34 Å. In the fifth B2- site, B2- is bonded in a tetrahedral geometry to four H+0.71+ atoms. There are a spread of B–H bond distances ranging from 1.20–1.26 Å. There are thirteen inequivalent H+0.71+ sites. In the first H+0.71+ site, H+0.71+ is bonded in a single-bond geometry to one B2- atom. In the second H+0.71+ site, H+0.71+ is bonded in a single-bond geometry to one B2- atom. In the third H+0.71+ site, H+0.71+ is bonded in a single-bond geometry to one B2- atom. In the fourth H+0.71+ site, H+0.71+ is bonded in an L-shaped geometry to one Be2+ and one B2- atom. In the fifth H+0.71+ site, H+0.71+ is bonded in a single-bond geometry to one B2- atom. In the sixth H+0.71+ site, H+0.71+ is bonded in an L-shaped geometry to one Be2+ and one B2- atom. In the seventh H+0.71+ site, H+0.71+ is bonded in an L-shaped geometry to one Be2+ and one B2- atom. In the eighth H+0.71+ site, H+0.71+ is bonded in an L-shaped geometry to one Be2+ and one B2- atom. In the ninth H+0.71+ site, H+0.71+ is bonded in a single-bond geometry to one B2- atom. In the tenth H+0.71+ site, H+0.71+ is bonded in an L-shaped geometry to two B2- atoms. In the eleventh H+0.71+ site, H+0.71+ is bonded in an L-shaped geometry to two B2- atoms. In the twelfth H+0.71+ site, H+0.71+ is bonded in an L-shaped geometry to two B2- atoms. In the thirteenth H+0.71+ site, H+0.71+ is bonded in a single-bond geometry to one B2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hf(Nb2B3)4 by Materials Project

Hf(Nb2B3)4 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Hf4+ is bonded to twelve B2- atoms to form a mixture of edge and face-sharing HfB12 cuboctahedra. There are eight shorter (2.48 Å) and four longer (2.53 Å) Hf–B bond lengths. There are four inequivalent Nb+2.50+ sites. In the first Nb+2.50+ site, Nb+2.50+ is bonded in a 7-coordinate geometry to seven B2- atoms. There are a spread of Nb–B bond distances ranging from 2.40–2.58 Å. In the second Nb+2.50+ site, Nb+2.50+ is bonded in a 7-coordinate geometry to seven B2- atoms. There are a spread of Nb–B bond distances ranging from 2.39–2.59 Å. In the third Nb+2.50+ site, Nb+2.50+ is bonded in a 7-coordinate geometry to seven B2- atoms. There are a spread of Nb–B bond distances ranging from 2.39–2.58 Å. In the fourth Nb+2.50+ site, Nb+2.50+ is bonded to twelve B2- atoms to form a mixture of edge and face-sharing NbB12 cuboctahedra. There are eight shorter (2.48 Å) and four longer (2.51 Å) Nb–B bond lengths. There are six inequivalent B2- sites. In the first B2- site, B2- is bonded in a 9-coordinate geometry to six Nb+2.50+ and three B2- atoms. There is one shorter (1.82 Å) and two longer (1.85 Å) B–B bond length. In the second B2- site, B2- is bonded in a 9-coordinate geometry to six Nb+2.50+ and three B2- atoms. Both B–B bond lengths are 1.85 Å. In the third B2- site, B2- is bonded in a 9-coordinate geometry to four equivalent Hf4+, two equivalent Nb+2.50+, and three B2- atoms. There is one shorter (1.84 Å) and two longer (1.85 Å) B–B bond length. In the fourth B2- site, B2- is bonded in a 9-coordinate geometry to seven Nb+2.50+ and two equivalent B2- atoms. In the fifth B2- site, B2- is bonded in a 9-coordinate geometry to seven Nb+2.50+ and two equivalent B2- atoms. In the sixth B2- site, B2- is bonded in a 9-coordinate geometry to two equivalent Hf4+, five Nb+2.50+, and two equivalent B2- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cr2(NiB2)3 by Materials Project

Cr2(NiB2)3 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are two inequivalent Cr3+ sites. In the first Cr3+ site, Cr3+ is bonded to twelve B2- atoms to form a mixture of edge and face-sharing CrB12 cuboctahedra. There are a spread of Cr–B bond distances ranging from 2.26–2.34 Å. In the second Cr3+ site, Cr3+ is bonded in a 7-coordinate geometry to seven B2- atoms. There are a spread of Cr–B bond distances ranging from 2.09–2.19 Å. There are three inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded in a 7-coordinate geometry to seven B2- atoms. There are a spread of Ni–B bond distances ranging from 2.10–2.17 Å. In the second Ni2+ site, Ni2+ is bonded in a 7-coordinate geometry to seven B2- atoms. There are a spread of Ni–B bond distances ranging from 2.12–2.19 Å. In the third Ni2+ site, Ni2+ is bonded in a 7-coordinate geometry to seven B2- atoms. There are a spread of Ni–B bond distances ranging from 2.14–2.18 Å. There are six inequivalent B2- sites. In the first B2- site, B2- is bonded in a 9-coordinate geometry to six Cr3+ and three B2- atoms. There is one shorter (1.73 Å) and two longer (1.76 Å) B–B bond length. In the second B2- site, B2- is bonded in a 9-coordinate geometry to four equivalent Cr3+, two equivalent Ni2+, and three B2- atoms. Both B–B bond lengths are 1.74 Å. In the third B2- site, B2- is bonded in a 9-coordinate geometry to one Cr3+, six Ni2+, and two equivalent B2- atoms. Both B–B bond lengths are 1.80 Å. In the fourth B2- site, B2- is bonded in a 9-coordinate geometry to seven Ni2+ and two equivalent B2- atoms. In the fifth B2- site, B2- is bonded in a 9-coordinate geometry to two equivalent Cr3+, five Ni2+, and two equivalent B2- atoms. In the sixth B2- site, B2- is bonded in a 9-coordinate geometry to six Cr3+, one Ni2+, and two equivalent B2- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cr3NiB6 by Materials Project

Cr3NiB6 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are three inequivalent Cr+3.33+ sites. In the first Cr+3.33+ site, Cr+3.33+ is bonded in a 7-coordinate geometry to seven B2- atoms. There are a spread of Cr–B bond distances ranging from 2.10–2.18 Å. In the second Cr+3.33+ site, Cr+3.33+ is bonded to twelve B2- atoms to form a mixture of edge and face-sharing CrB12 cuboctahedra. There are a spread of Cr–B bond distances ranging from 2.26–2.38 Å. In the third Cr+3.33+ site, Cr+3.33+ is bonded to twelve B2- atoms to form a mixture of edge and face-sharing CrB12 cuboctahedra. There are a spread of Cr–B bond distances ranging from 2.27–2.36 Å. Ni2+ is bonded in a 7-coordinate geometry to seven B2- atoms. There are a spread of Ni–B bond distances ranging from 2.08–2.19 Å. There are six inequivalent B2- sites. In the first B2- site, B2- is bonded in a 9-coordinate geometry to six Cr+3.33+ and three B2- atoms. There is two shorter (1.71 Å) and one longer (1.72 Å) B–B bond length. In the second B2- site, B2- is bonded in a 9-coordinate geometry to six Cr+3.33+ and three B2- atoms. The B–B bond length is 1.73 Å. In the third B2- site, B2- is bonded in a 9-coordinate geometry to six Cr+3.33+, one Ni2+, and two equivalent B2- atoms. Both B–B bond lengths are 1.77 Å. In the fourth B2- site, B2- is bonded in a 9-coordinate geometry to three Cr+3.33+, four equivalent Ni2+, and two equivalent B2- atoms. Both B–B bond lengths are 1.76 Å. In the fifth B2- site, B2- is bonded in a 9-coordinate geometry to four equivalent Cr+3.33+, two equivalent Ni2+, and three B2- atoms. In the sixth B2- site, B2- is bonded in a 9-coordinate geometry to six Cr+3.33+ and three B2- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y2ReB6 by Materials Project

Y2ReB6 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. there are two inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded in a 4-coordinate geometry to fourteen B2- atoms. There are a spread of Y–B bond distances ranging from 2.76–2.84 Å. In the second Y3+ site, Y3+ is bonded to twelve B2- atoms to form a mixture of face and edge-sharing YB12 cuboctahedra. There are a spread of Y–B bond distances ranging from 2.61–2.63 Å. Re6+ is bonded in a 10-coordinate geometry to ten B2- atoms. There are a spread of Re–B bond distances ranging from 2.37–2.42 Å. There are six inequivalent B2- sites. In the first B2- site, B2- is bonded in a 9-coordinate geometry to six Y3+ and three B2- atoms. There are a spread of B–B bond distances ranging from 1.85–1.96 Å. In the second B2- site, B2- is bonded in a 3-coordinate geometry to four equivalent Y3+, two equivalent Re6+, and three B2- atoms. There is two shorter (1.80 Å) and one longer (1.84 Å) B–B bond length. In the third B2- site, B2- is bonded in a 9-coordinate geometry to four Y3+, two equivalent Re6+, and three B2- atoms. The B–B bond length is 1.81 Å. In the fourth B2- site, B2- is bonded in a 9-coordinate geometry to four Y3+, two equivalent Re6+, and three B2- atoms. There is one shorter (1.74 Å) and one longer (1.86 Å) B–B bond length. In the fifth B2- site, B2- is bonded in a 9-coordinate geometry to four Y3+, two equivalent Re6+, and three B2- atoms. The B–B bond length is 1.81 Å. In the sixth B2- site, B2- is bonded in a 9-coordinate geometry to four Y3+, two equivalent Re6+, and three B2- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Materials Data on Sc2ReB6 by Materials Project

Sc2ReB6 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. there are two inequivalent Sc3+ sites. In the first Sc3+ site, Sc3+ is bonded in a 10-coordinate geometry to fourteen B2- atoms. There are a spread of Sc–B bond distances ranging from 2.64–2.75 Å. In the second Sc3+ site, Sc3+ is bonded to twelve B2- atoms to form a mixture of edge and face-sharing ScB12 cuboctahedra. There are a spread of Sc–B bond distances ranging from 2.49–2.52 Å. Re6+ is bonded in a 10-coordinate geometry to ten B2- atoms. There are a spread of Re–B bond distances ranging from 2.30–2.34 Å. There are six inequivalent B2- sites. In the first B2- site, B2- is bonded in a 9-coordinate geometry to six Sc3+ and three B2- atoms. There is two shorter (1.77 Å) and one longer (1.84 Å) B–B bond length. In the second B2- site, B2- is bonded in a 3-coordinate geometry to four equivalent Sc3+, two equivalent Re6+, and three B2- atoms. There are a spread of B–B bond distances ranging from 1.74–1.80 Å. In the third B2- site, B2- is bonded in a 9-coordinate geometry to four Sc3+, two equivalent Re6+, and three B2- atoms. The B–B bond length is 1.81 Å. In the fourth B2- site, B2- is bonded in a 9-coordinate geometry to four Sc3+, two equivalent Re6+, and three B2- atoms. Both B–B bond lengths are 1.74 Å. In the fifth B2- site, B2- is bonded in a 9-coordinate geometry to four Sc3+, two equivalent Re6+, and three B2- atoms. The B–B bond length is 1.79 Å. In the sixth B2- site, B2- is bonded in a 9-coordinate geometry to four Sc3+, two equivalent Re6+, and three B2- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm2ReB6 by Materials Project

Tm2ReB6 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. there are two inequivalent Tm3+ sites. In the first Tm3+ site, Tm3+ is bonded in a 4-coordinate geometry to fourteen B2- atoms. There are a spread of Tm–B bond distances ranging from 2.72–2.81 Å. In the second Tm3+ site, Tm3+ is bonded to twelve B2- atoms to form a mixture of face and edge-sharing TmB12 cuboctahedra. There are four shorter (2.57 Å) and eight longer (2.59 Å) Tm–B bond lengths. Re6+ is bonded in a 10-coordinate geometry to ten B2- atoms. There are a spread of Re–B bond distances ranging from 2.34–2.39 Å. There are six inequivalent B2- sites. In the first B2- site, B2- is bonded in a 9-coordinate geometry to six Tm3+ and three B2- atoms. There are a spread of B–B bond distances ranging from 1.83–1.93 Å. In the second B2- site, B2- is bonded in a 3-coordinate geometry to four equivalent Tm3+, two equivalent Re6+, and three B2- atoms. There are a spread of B–B bond distances ranging from 1.79–1.81 Å. In the third B2- site, B2- is bonded in a 9-coordinate geometry to four Tm3+, two equivalent Re6+, and three B2- atoms. The B–B bond length is 1.81 Å. In the fourth B2- site, B2- is bonded in a 9-coordinate geometry to four Tm3+, two equivalent Re6+, and three B2- atoms. There is one shorter (1.74 Å) and one longer (1.82 Å) B–B bond length. In the fifth B2- site, B2- is bonded in a 9-coordinate geometry to four Tm3+, two equivalent Re6+, and three B2- atoms. The B–B bond length is 1.80 Å. In the sixth B2- site, B2- is bonded in a 9-coordinate geometry to four Tm3+, two equivalent Re6+, and three B2- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Er2ReB6 by Materials Project

Er2ReB6 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. there are two inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded in a 4-coordinate geometry to fourteen B2- atoms. There are a spread of Er–B bond distances ranging from 2.73–2.82 Å. In the second Er3+ site, Er3+ is bonded to twelve B2- atoms to form a mixture of edge and face-sharing ErB12 cuboctahedra. There are a spread of Er–B bond distances ranging from 2.58–2.61 Å. Re6+ is bonded in a 10-coordinate geometry to ten B2- atoms. There are a spread of Re–B bond distances ranging from 2.35–2.40 Å. There are six inequivalent B2- sites. In the first B2- site, B2- is bonded in a 9-coordinate geometry to six Er3+ and three B2- atoms. There are a spread of B–B bond distances ranging from 1.84–1.95 Å. In the second B2- site, B2- is bonded in a 3-coordinate geometry to four equivalent Er3+, two equivalent Re6+, and three B2- atoms. There are a spread of B–B bond distances ranging from 1.79–1.82 Å. In the third B2- site, B2- is bonded in a 9-coordinate geometry to four Er3+, two equivalent Re6+, and three B2- atoms. The B–B bond length is 1.81 Å. In the fourth B2- site, B2- is bonded in a 9-coordinate geometry to four Er3+, two equivalent Re6+, and three B2- atoms. There is one shorter (1.74 Å) and one longer (1.84 Å) B–B bond length. In the fifth B2- site, B2- is bonded in a 9-coordinate geometry to four Er3+, two equivalent Re6+, and three B2- atoms. The B–B bond length is 1.80 Å. In the sixth B2- site, B2- is bonded in a 9-coordinate geometry to four Er3+, two equivalent Re6+, and three B2- atoms.

36 MATERIALS SCIENCE↗