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At least 1,189 records · Page 66
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DOE OSTI2020

Materials Data on BaMg6W by Materials Project

BaMg6W crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Ba is bonded to twelve Mg atoms to form BaMg12 cuboctahedra that share corners with four equivalent BaMg12 cuboctahedra, corners with eight equivalent WMg12 cuboctahedra, edges with eight equivalent MgBa2Mg8W2 cuboctahedra, faces with two equivalent BaMg12 cuboctahedra, faces with four equivalent MgBa2Mg8W2 cuboctahedra, and faces with four equivalent WMg12 cuboctahedra. There are four shorter (3.34 Å) and eight longer (3.49 Å) Ba–Mg bond lengths. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded to two equivalent Ba, eight Mg, and two equivalent W atoms to form distorted MgBa2Mg8W2 cuboctahedra that share corners with twelve equivalent MgBa2Mg8W2 cuboctahedra, edges with four equivalent BaMg12 cuboctahedra, edges with four equivalent WMg12 cuboctahedra, faces with two equivalent BaMg12 cuboctahedra, faces with two equivalent WMg12 cuboctahedra, and faces with six equivalent MgBa2Mg8W2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.21–3.26 Å. There are one shorter (3.30 Å) and one longer (3.39 Å) Mg–W bond lengths. In the second Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Ba, four equivalent Mg, and two equivalent W atoms. Both Mg–W bond lengths are 2.96 Å. In the third Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Ba, four equivalent Mg, and two equivalent W atoms. Both Mg–W bond lengths are 2.96 Å. In the fourth Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Ba, four equivalent Mg, and two equivalent W atoms. Both Mg–W bond lengths are 2.97 Å. W is bonded to twelve Mg atoms to form WMg12 cuboctahedra that share corners with four equivalent WMg12 cuboctahedra, corners with eight equivalent BaMg12 cuboctahedra, edges with eight equivalent MgBa2Mg8W2 cuboctahedra, faces with two equivalent WMg12 cuboctahedra, faces with four equivalent BaMg12 cuboctahedra, and faces with four equivalent MgBa2Mg8W2 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg6VW by Materials Project

Mg6VW crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are four inequivalent Mg sites. In the first Mg site, Mg is bonded to eight Mg, two equivalent V, and two equivalent W atoms to form distorted MgMg8V2W2 cuboctahedra that share corners with four equivalent VMg10W2 cuboctahedra, corners with four equivalent WMg10V2 cuboctahedra, corners with ten equivalent MgMg8V2W2 cuboctahedra, edges with two equivalent VMg10W2 cuboctahedra, edges with two equivalent WMg10V2 cuboctahedra, edges with six MgMg8V2W2 cuboctahedra, faces with two equivalent VMg10W2 cuboctahedra, faces with two equivalent WMg10V2 cuboctahedra, and faces with six MgMg8V2W2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 2.90–3.06 Å. There are one shorter (3.05 Å) and one longer (3.10 Å) Mg–V bond lengths. There are one shorter (3.06 Å) and one longer (3.10 Å) Mg–W bond lengths. In the second Mg site, Mg is bonded in a 12-coordinate geometry to eight Mg, two equivalent V, and two equivalent W atoms. There are a spread of Mg–Mg bond distances ranging from 2.83–3.26 Å. Both Mg–V bond lengths are 3.01 Å. Both Mg–W bond lengths are 2.99 Å. In the third Mg site, Mg is bonded to ten Mg and two equivalent V atoms to form distorted MgMg10V2 cuboctahedra that share corners with six equivalent MgMg10V2 cuboctahedra, edges with four equivalent VMg10W2 cuboctahedra, edges with eight equivalent MgMg8V2W2 cuboctahedra, faces with two equivalent VMg10W2 cuboctahedra, faces with six MgMg8V2W2 cuboctahedra, and faces with six equivalent WMg10V2 cuboctahedra. Both Mg–Mg bond lengths are 2.90 Å. Both Mg–V bond lengths are 2.95 Å. In the fourth Mg site, Mg is bonded in a distorted bent 120 degrees geometry to ten Mg and two equivalent W atoms. Both Mg–W bond lengths are 2.92 Å. V is bonded to ten Mg and two equivalent W atoms to form VMg10W2 cuboctahedra that share corners with four equivalent WMg10V2 cuboctahedra, corners with six equivalent VMg10W2 cuboctahedra, corners with eight equivalent MgMg8V2W2 cuboctahedra, edges with two equivalent WMg10V2 cuboctahedra, edges with eight MgMg8V2W2 cuboctahedra, faces with two equivalent VMg10W2 cuboctahedra, faces with two equivalent WMg10V2 cuboctahedra, and faces with six MgMg8V2W2 cuboctahedra. Both V–W bond lengths are 2.90 Å. W is bonded to ten Mg and two equivalent V atoms to form WMg10V2 cuboctahedra that share corners with four equivalent VMg10W2 cuboctahedra, corners with six equivalent WMg10V2 cuboctahedra, corners with eight equivalent MgMg8V2W2 cuboctahedra, edges with two equivalent VMg10W2 cuboctahedra, edges with four equivalent MgMg8V2W2 cuboctahedra, faces with two equivalent VMg10W2 cuboctahedra, faces with two equivalent WMg10V2 cuboctahedra, and faces with ten MgMg8V2W2 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg14FeW by Materials Project

Mg14WFe crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are seven inequivalent Mg sites. In the first Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent WMg10Fe2 cuboctahedra, corners with fourteen MgMg12 cuboctahedra, edges with six MgMg12 cuboctahedra, faces with two equivalent FeMg10W2 cuboctahedra, and faces with six MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.00–3.20 Å. In the second Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent FeMg10W2 cuboctahedra, corners with fourteen MgMg12 cuboctahedra, edges with six MgMg12 cuboctahedra, faces with two equivalent WMg10Fe2 cuboctahedra, and faces with six MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.07–3.20 Å. In the third Mg site, Mg is bonded to eight Mg, two equivalent W, and two equivalent Fe atoms to form distorted MgMg8Fe2W2 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, edges with two equivalent MgMg8Fe2W2 cuboctahedra, edges with two equivalent WMg10Fe2 cuboctahedra, edges with two equivalent FeMg10W2 cuboctahedra, faces with two equivalent WMg10Fe2 cuboctahedra, faces with two equivalent FeMg10W2 cuboctahedra, and faces with four MgMg8Fe2W2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 2.91–3.03 Å. There are one shorter (3.03 Å) and one longer (3.21 Å) Mg–W bond lengths. There are one shorter (3.10 Å) and one longer (3.14 Å) Mg–Fe bond lengths. In the fourth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent WMg10Fe2 cuboctahedra, corners with four equivalent FeMg10W2 cuboctahedra, corners with ten MgMg8Fe2W2 cuboctahedra, edges with six MgMg12 cuboctahedra, and faces with eight MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 2.99–3.25 Å. In the fifth Mg site, Mg is bonded in a 12-coordinate geometry to four Mg, one W, and one Fe atom. The Mg–W bond length is 2.90 Å. The Mg–Fe bond length is 2.87 Å. In the sixth Mg site, Mg is bonded in a distorted single-bond geometry to five Mg and one Fe atom. The Mg–Fe bond length is 2.86 Å. In the seventh Mg site, Mg is bonded in a distorted single-bond geometry to five Mg and one W atom. The Mg–W bond length is 2.92 Å. W is bonded to ten Mg and two equivalent Fe atoms to form WMg10Fe2 cuboctahedra that share corners with six equivalent WMg10Fe2 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with two equivalent FeMg10W2 cuboctahedra, edges with four equivalent MgMg8Fe2W2 cuboctahedra, faces with two equivalent FeMg10W2 cuboctahedra, and faces with six MgMg12 cuboctahedra. Both W–Fe bond lengths are 3.00 Å. Fe is bonded to ten Mg and two equivalent W atoms to form FeMg10W2 cuboctahedra that share corners with six equivalent FeMg10W2 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with two equivalent WMg10Fe2 cuboctahedra, edges with four equivalent MgMg8Fe2W2 cuboctahedra, faces with two equivalent WMg10Fe2 cuboctahedra, and faces with six MgMg12 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KMg6W by Materials Project

KMg6W crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. K is bonded to twelve Mg atoms to form KMg12 cuboctahedra that share corners with four equivalent KMg12 cuboctahedra, corners with eight equivalent WMg12 cuboctahedra, edges with eight equivalent MgK2Mg8W2 cuboctahedra, faces with two equivalent KMg12 cuboctahedra, faces with four equivalent MgK2Mg8W2 cuboctahedra, and faces with four equivalent WMg12 cuboctahedra. There are a spread of K–Mg bond distances ranging from 3.27–3.44 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded to two equivalent K, eight Mg, and two equivalent W atoms to form distorted MgK2Mg8W2 cuboctahedra that share corners with twelve equivalent MgK2Mg8W2 cuboctahedra, edges with four equivalent KMg12 cuboctahedra, edges with four equivalent WMg12 cuboctahedra, faces with two equivalent KMg12 cuboctahedra, faces with two equivalent WMg12 cuboctahedra, and faces with six equivalent MgK2Mg8W2 cuboctahedra. There are two shorter (3.20 Å) and six longer (3.21 Å) Mg–Mg bond lengths. There are one shorter (3.26 Å) and one longer (3.29 Å) Mg–W bond lengths. In the second Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent K, six Mg, and two equivalent W atoms. Both Mg–Mg bond lengths are 2.82 Å. Both Mg–W bond lengths are 2.95 Å. In the third Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent K, six Mg, and two equivalent W atoms. Both Mg–W bond lengths are 2.98 Å. In the fourth Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent K, six Mg, and two equivalent W atoms. Both Mg–W bond lengths are 2.97 Å. W is bonded to twelve Mg atoms to form WMg12 cuboctahedra that share corners with four equivalent WMg12 cuboctahedra, corners with eight equivalent KMg12 cuboctahedra, edges with eight equivalent MgK2Mg8W2 cuboctahedra, faces with two equivalent WMg12 cuboctahedra, faces with four equivalent KMg12 cuboctahedra, and faces with four equivalent MgK2Mg8W2 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaMg6W by Materials Project

NaMg6W crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Na is bonded to twelve Mg atoms to form NaMg12 cuboctahedra that share corners with four equivalent NaMg12 cuboctahedra, corners with eight equivalent WMg12 cuboctahedra, edges with eight equivalent MgNa2Mg8W2 cuboctahedra, faces with two equivalent NaMg12 cuboctahedra, faces with four equivalent MgNa2Mg8W2 cuboctahedra, and faces with four equivalent WMg12 cuboctahedra. There are a spread of Na–Mg bond distances ranging from 3.10–3.26 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded to two equivalent Na, eight Mg, and two equivalent W atoms to form distorted MgNa2Mg8W2 cuboctahedra that share corners with twelve equivalent MgNa2Mg8W2 cuboctahedra, edges with four equivalent NaMg12 cuboctahedra, edges with four equivalent WMg12 cuboctahedra, faces with two equivalent NaMg12 cuboctahedra, faces with two equivalent WMg12 cuboctahedra, and faces with six equivalent MgNa2Mg8W2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.09–3.13 Å. There are one shorter (3.10 Å) and one longer (3.12 Å) Mg–W bond lengths. In the second Mg site, Mg is bonded in a 12-coordinate geometry to two equivalent Na, eight Mg, and two equivalent W atoms. There are a spread of Mg–Mg bond distances ranging from 2.85–3.37 Å. Both Mg–W bond lengths are 2.97 Å. In the third Mg site, Mg is bonded in a 12-coordinate geometry to two equivalent Na, eight Mg, and two equivalent W atoms. Both Mg–W bond lengths are 2.98 Å. In the fourth Mg site, Mg is bonded in a 12-coordinate geometry to two equivalent Na, eight Mg, and two equivalent W atoms. Both Mg–W bond lengths are 3.00 Å. W is bonded to twelve Mg atoms to form WMg12 cuboctahedra that share corners with four equivalent WMg12 cuboctahedra, corners with eight equivalent NaMg12 cuboctahedra, edges with eight equivalent MgNa2Mg8W2 cuboctahedra, faces with two equivalent WMg12 cuboctahedra, faces with four equivalent NaMg12 cuboctahedra, and faces with four equivalent MgNa2Mg8W2 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on W2Cl4O7 by Materials Project

(WO3Cl2)4O2 crystallizes in the orthorhombic Ccce space group. The structure is zero-dimensional and consists of eight water molecules and four WO3Cl2 clusters. In each WO3Cl2 cluster, W is bonded in a 6-coordinate geometry to four O and two Cl atoms. There are a spread of W–O bond distances ranging from 1.73–2.15 Å. There are one shorter (2.37 Å) and one longer (2.43 Å) W–Cl bond lengths. There are four inequivalent O sites. In the first O site, O is bonded in a linear geometry to two equivalent W atoms. In the second O site, O is bonded in a linear geometry to two equivalent W atoms. In the third O site, O is bonded in a single-bond geometry to one W atom. In the fourth O site, O is bonded in a single-bond geometry to one W atom. There are two inequivalent Cl sites. In the first Cl site, Cl is bonded in a distorted single-bond geometry to one W atom. In the second Cl site, Cl is bonded in a single-bond geometry to one W atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on V2Co9W by Materials Project

V2WCo9 is beta Cu3Ti-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are two inequivalent V sites. In the first V site, V is bonded to twelve Co atoms to form VCo12 cuboctahedra that share corners with three equivalent WCo12 cuboctahedra, corners with six equivalent VCo12 cuboctahedra, corners with six equivalent CoV3Co8W cuboctahedra, edges with twenty-one CoV2Co8W2 cuboctahedra, faces with three equivalent WCo12 cuboctahedra, faces with four equivalent VCo12 cuboctahedra, and faces with twelve CoV3Co8W cuboctahedra. There are a spread of V–Co bond distances ranging from 2.46–2.53 Å. In the second V site, V is bonded to twelve Co atoms to form VCo12 cuboctahedra that share corners with six equivalent VCo12 cuboctahedra, corners with twelve CoV2Co8W2 cuboctahedra, edges with eighteen CoV2Co8W2 cuboctahedra, faces with four equivalent VCo12 cuboctahedra, faces with four equivalent WCo12 cuboctahedra, and faces with twelve CoV3Co8W cuboctahedra. There are six shorter (2.50 Å) and six longer (2.51 Å) V–Co bond lengths. W is bonded to twelve Co atoms to form WCo12 cuboctahedra that share corners with three equivalent VCo12 cuboctahedra, corners with six equivalent WCo12 cuboctahedra, corners with six equivalent CoV3Co8W cuboctahedra, edges with twenty-one CoV2Co8W2 cuboctahedra, faces with seven VCo12 cuboctahedra, and faces with twelve CoV3Co8W cuboctahedra. There are a spread of W–Co bond distances ranging from 2.50–2.55 Å. There are five inequivalent Co sites. In the first Co site, Co is bonded to three V, one W, and eight Co atoms to form distorted CoV3Co8W cuboctahedra that share corners with two equivalent VCo12 cuboctahedra, corners with thirteen CoV2Co8W2 cuboctahedra, edges with three equivalent WCo12 cuboctahedra, edges with four VCo12 cuboctahedra, edges with fourteen CoV3Co8W cuboctahedra, a faceface with one WCo12 cuboctahedra, faces with three VCo12 cuboctahedra, and faces with fifteen CoV3Co8W cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.43–2.59 Å. In the second Co site, Co is bonded to two V, two equivalent W, and eight Co atoms to form distorted CoV2Co8W2 cuboctahedra that share corners with two equivalent VCo12 cuboctahedra, corners with thirteen CoV2Co8W2 cuboctahedra, edges with two equivalent WCo12 cuboctahedra, edges with five VCo12 cuboctahedra, edges with fourteen CoV3Co8W cuboctahedra, faces with two VCo12 cuboctahedra, faces with two equivalent WCo12 cuboctahedra, and faces with fifteen CoV3Co8W cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.44–2.57 Å. In the third Co site, Co is bonded to three V, one W, and eight Co atoms to form distorted CoV3Co8W cuboctahedra that share corners with two equivalent VCo12 cuboctahedra, corners with two equivalent WCo12 cuboctahedra, corners with fourteen CoV3Co8W cuboctahedra, edges with two equivalent WCo12 cuboctahedra, edges with four VCo12 cuboctahedra, edges with twelve CoV3Co8W cuboctahedra, a faceface with one WCo12 cuboctahedra, faces with three VCo12 cuboctahedra, and faces with sixteen CoV3Co8W cuboctahedra. There are three shorter (2.48 Å) and two longer (2.53 Å) Co–Co bond lengths. In the fourth Co site, Co is bonded to three V, one W, and eight Co atoms to form distorted CoV3Co8W cuboctahedra that share corners with two equivalent VCo12 cuboctahedra, corners with thirteen CoV2Co8W2 cuboctahedra, edges with three equivalent WCo12 cuboctahedra, edges with four VCo12 cuboctahedra, edges with fourteen CoV3Co8W cuboctahedra, a faceface with one WCo12 cuboctahedra, faces with three VCo12 cuboctahedra, and faces with fifteen CoV3Co8W cuboctahedra. Both Co–V bond lengths are 2.51 Å. The Co–W bond length is 2.50 Å. There are a spread of Co–Co bond distances ranging from 2.43–2.59 Å. In the fifth Co site, Co is bonded to two V, two equivalent W, and eight Co atoms to form distorted CoV2Co8W2 cuboctahedra that share corners with two equivalent VCo12 cuboctahedra, corners with thirteen CoV2Co8W2 cuboctahedra, edges with two equivalent WCo12 cuboctahedra, edges with five VCo12 cuboctahedra, edges with fourteen CoV3Co8W cuboctahedra, faces with two VCo12 cuboctahedra, faces with two equivalent WCo12 cuboctahedra, and faces with fifteen CoV3Co8W cuboctahedra. There are one shorter (2.46 Å) and one longer (2.50 Å) Co–V bond lengths. Both Co–W bond lengths are 2.51 Å. There are a spread of Co–Co bond distances ranging from 2.44–2.57 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbMg6W by Materials Project

RbMg6W crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Rb is bonded to twelve Mg atoms to form RbMg12 cuboctahedra that share corners with four equivalent RbMg12 cuboctahedra, corners with eight equivalent WMg12 cuboctahedra, edges with eight equivalent MgRb2Mg8W2 cuboctahedra, faces with two equivalent RbMg12 cuboctahedra, faces with four equivalent MgRb2Mg8W2 cuboctahedra, and faces with four equivalent WMg12 cuboctahedra. There are a spread of Rb–Mg bond distances ranging from 3.37–3.54 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded to two equivalent Rb, eight Mg, and two equivalent W atoms to form distorted MgRb2Mg8W2 cuboctahedra that share corners with twelve equivalent MgRb2Mg8W2 cuboctahedra, edges with four equivalent RbMg12 cuboctahedra, edges with four equivalent WMg12 cuboctahedra, faces with two equivalent RbMg12 cuboctahedra, faces with two equivalent WMg12 cuboctahedra, and faces with six equivalent MgRb2Mg8W2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.24–3.27 Å. There are one shorter (3.36 Å) and one longer (3.38 Å) Mg–W bond lengths. In the second Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Rb, four equivalent Mg, and two equivalent W atoms. Both Mg–W bond lengths are 2.95 Å. In the third Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Rb, four equivalent Mg, and two equivalent W atoms. Both Mg–W bond lengths are 2.94 Å. In the fourth Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Rb, four equivalent Mg, and two equivalent W atoms. Both Mg–W bond lengths are 2.93 Å. W is bonded to twelve Mg atoms to form WMg12 cuboctahedra that share corners with four equivalent WMg12 cuboctahedra, corners with eight equivalent RbMg12 cuboctahedra, edges with eight equivalent MgRb2Mg8W2 cuboctahedra, faces with two equivalent WMg12 cuboctahedra, faces with four equivalent RbMg12 cuboctahedra, and faces with four equivalent MgRb2Mg8W2 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrMg6W by Materials Project

SrMg6W crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Sr is bonded to twelve Mg atoms to form SrMg12 cuboctahedra that share corners with four equivalent SrMg12 cuboctahedra, corners with eight equivalent WMg12 cuboctahedra, edges with eight equivalent MgSr2Mg8W2 cuboctahedra, faces with two equivalent SrMg12 cuboctahedra, faces with four equivalent MgSr2Mg8W2 cuboctahedra, and faces with four equivalent WMg12 cuboctahedra. There are a spread of Sr–Mg bond distances ranging from 3.24–3.41 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded to two equivalent Sr, eight Mg, and two equivalent W atoms to form distorted MgSr2Mg8W2 cuboctahedra that share corners with twelve equivalent MgSr2Mg8W2 cuboctahedra, edges with four equivalent SrMg12 cuboctahedra, edges with four equivalent WMg12 cuboctahedra, faces with two equivalent SrMg12 cuboctahedra, faces with two equivalent WMg12 cuboctahedra, and faces with six equivalent MgSr2Mg8W2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.17–3.22 Å. There are one shorter (3.21 Å) and one longer (3.28 Å) Mg–W bond lengths. In the second Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Sr, six Mg, and two equivalent W atoms. There are one shorter (2.83 Å) and one longer (2.84 Å) Mg–Mg bond lengths. Both Mg–W bond lengths are 2.97 Å. In the third Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Sr, six Mg, and two equivalent W atoms. Both Mg–W bond lengths are 3.00 Å. In the fourth Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Sr, six Mg, and two equivalent W atoms. Both Mg–W bond lengths are 3.00 Å. W is bonded to twelve Mg atoms to form WMg12 cuboctahedra that share corners with four equivalent WMg12 cuboctahedra, corners with eight equivalent SrMg12 cuboctahedra, edges with eight equivalent MgSr2Mg8W2 cuboctahedra, faces with two equivalent WMg12 cuboctahedra, faces with four equivalent SrMg12 cuboctahedra, and faces with four equivalent MgSr2Mg8W2 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2022

The Pantheon+ Analysis: Cosmological Constraints

We present constraints on cosmological parameters from the Pantheon+ analysis of 1701 light curves of 1550 distinct Type Ia supernovae (SNe Ia) ranging in redshift from z = 0.001 to 2.26. This work features an increased sample size from the addition of multiple cross-calibrated photometric systems of SNe covering an increased redshift span, and improved treatments of systematic uncertainties in comparison to the original Pantheon analysis, which together result in a factor of 2 improvement in cosmological constraining power. For a flat ΛCDM model, we find Ω M = 0.334 ± 0.018 from SNe Ia alone. For a flat w 0 CDM model, we measure w 0 = –0.90 ± 0.14 from SNe Ia alone, H 0 = 73.5 ± 1.1 km s –1 Mpc –1 when including the Cepheid host distances and covariance (SH0ES), and w 0 = $-{0.978}_{-0.031}^{+0.024}$ when combining the SN likelihood with Planck constraints from the cosmic microwave background (CMB) and baryon acoustic oscillations (BAO); both w 0 values are consistent with a cosmological constant. We also present the most precise measurements to date on the evolution of dark energy in a flat w 0 w a CDM universe, and measure w a = $-{0.1}_{-2.0}^{+0.9}$ from Pantheon+ SNe Ia alone, H 0 = 73.3 ± 1.1 km s –1 Mpc –1 when including SH0ES Cepheid distances, and w a = $-{0.65}_{-0.32}^{+0.28}$ when combining Pantheon+ SNe Ia with CMB and BAO data. Finally, we find that systematic uncertainties in the use of SNe Ia along the distance ladder comprise less than one-third of the total uncertainty in the measurement of H 0 and cannot explain the present "Hubble tension" between local measurements and early universe predictions from the cosmological model.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2022

Liquid lithium wetting and percolation in a porous tungsten/liquid Li plasma facing component (PFC)

This work explores the concept of a hybrid material system designed to protect the plasma from high-Z material emission while also protecting an underlying high-Z wall material from erosion by integrating a low-Z component in the liquid phase. Plasma-surface interaction properties of a porous tungsten (W)-liquid metal hybrid system, having the favorable bulk thermomechanical properties of W while serving as a scaffold for a liquid metal with self-healing and radiative vapor shielding characteristics, are examined. W-substrates with 70% density of bulk W and 1–5 μm sized pores have been fabricated with 50-nm W powders using spark plasma sintering. Enhanced lithium (Li) wettability, driven by percolation through the porous W architecture, is demonstrated with in-situ liquid Li drop measurements. Finally, results show complete wetting of liquid Li at 250 °C in the porous W, 100 °C lower temperature than what has been observed on traditional W surfaces. In operando ion beam analysis of Li films deposited on porous W substrates provides microscopic evidence of Li percolation into the substrate and a first look at D retention up to a depth of 100 nm after plasma exposure at a flux of 10 20 m –2 s –1 , 250 eV/amu D + plasma to a fluence of 1.16 × 10 23 m –2 at a temperature of 200 °C.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2020

Tailoring ductile-phase toughened tungsten hierarchical microstructures for plasma-facing materials

Biological materials, such as bones, nacre, etc., have been found to show attractive and unique combinations of stiffness, strength and fracture toughness. Research has been conducted in various engineering areas to mimic the naturally hierarchical microstructures or nanostructures of these materials to produce materials with optimum stiffness, high strength and fracture toughness for their intended structural applications. In the same objective, this work applies a multiscale microstructural approach recently developed to investigate the deformation and fracture behavior of ductile phase toughened tungsten (W) materials such as tungsten-nickel/iron (W-Ni/Fe) composites that possess lamellar-like and hierarchical “brick-and-mortar” (BAM) microstructures. First, the approach is used to simulate tensile loading of W-Ni/Fe specimens cut out from hot-rolled W-Ni/Fe plates which possess lamellar-like microstructures. The finite element model of the gage section of the specimen consists of a W-Ni/Fe dual-phase microstructural domain in which the constitutive behaviors of W and Ni/Fe phases are described by an elastic-plastic damage model. The predicted material stress-strain response and crack pattern development as a function of loading are then compared to the corresponding experimental results to determine the constitutive model parameters for W and Ni/Fe. Subsequently, the model parameters are used to analyze W-Ni/Fe BAM microstructures that are artificially created to investigate the effects of microstructural features and morphologies on the composite stress-strain response, damage, and fracture patterns. The modeling shows that regular BAM microstructures that experience bridging mechanism combined with crack penetration across W-phase regions exhibit significantly higher strengths than the rather random lamellar-like microstructures. More significantly, however adjusting the brick’s length-to-height ratio, the BAM microstructure can be designed to allow a more distributed damage zone which leads to increased strength, ductility and fracture energy.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Retention and surface morphology evaluation of fine-grain dispersion-strengthened tungsten for plasma-facing component applications

This study exposed novel fine-grain dispersion-strengthened tungsten (W) to high fluence, low energy deuterium (D) and helium (He) plasmas to evaluate how material microstructure and composition affect hydrogen retention and surface morphology. Tested materials included fine-grain dispersion-strengthened tungsten (DSW) with 3 wt% zirconium carbide (ZrC) dispersoids, fine-grain dense W without any dispersoids (FGW), and coarse-grained polycrystalline ‘ITER-grade’ W. Samples were exposed to D 2 + and He + plasmas at fusion-relevant fluences (∼10 25 m -2 ) and ion energies (75 eV) over a range of temperatures (200 °C, 300 °C, 450 °C for D, 850 °C for He). Helium ion microscopy was performed on the exposed samples to evaluate surface morphology changes and material integrity. After D plasma exposure, the ZrC dispersoids showed near-surface degradation at exposure temperatures above 300 °C, but no detrimental morphology changes were observed for the adjacent W grains. After He plasma-exposure, nano-structured fuzz formation was observed in the tungsten matrix of all samples. The ZrC dispersoids maintained their integrity despite the surrounding fuzz growth, with clear delineation between the W fuzz and dispersoid regions. Thermal desorption spectroscopy showed that ZrC DSW consistently retained more D than the FGW by about a factor of 2 across all temperatures. At 200 °C and 300 °C, the ITER-W displayed lower D retention than both the DSW and FGW, however at 450 °C ITER-W showed the highest retention, about 50% more than DSW. He retention was comparable across all samples, with the highest retention observed in the fine-grain W, only 26% higher than in ITER-W. These insights on retention behavior will inform further optimization of these novel fine-grained tungsten materials with and without dispersoid additives.

Dispersion-strengthened tungsten↗
DOE OSTI2025

Formation of tungsten ethylidene complexes from diethyl complexes through a proton-catalyzed rearrangement of ethylene

Here, W(NAr) 2 Et 2 (Ar = 2,6-diisopropylphenyl) reacts with two equivalents of R F9 OH (OR F9 = OC(CF 3 ) 3 ) to yield W(NAr)(ArNH 2 )(OR F9 )2(C 2 H 4 ) complexes and ethane. In solution W(NAr)(ArNH 2 )(OR F9 ) 2 (C 2 H 4 ) decomposes to give R F9 OH, ethane, W(NAr)(OR F9 ) 2 (C 2 H 4 ), and W(NAr)(NHAr′)(ArNH 2 )(OR F9 ), in which Ar′ contains a dehydrogenated isopropyl group (Ar′ = (2-i-Pr)(6-CMe=CH 2 )C 6 H 3 ) coordinated to the metal. On a similar time scale W(NAr)(OR F9 ) 2 (CHCH 3 ) complexes are formed from W(NAr)(OR F9 ) 2 (C 2 H 4 ) through an ArNH 2 -catalyzed rearrangement of the ethylene ligand. W(NAr)(NHAr′)(ArNH 2 )(OR F9 ) reacts with cyclohexene to form methylenecyclohexene and complexes that contain an NHAr″ ligand where Ar″ is a disubstituted (methyl/aryl) alkylidene, (2-i-Pr)(6-CMe)C 6 H 3 ) that is tethered to the metal through the amido nitrogen. In contrast to W(NAr)(ArNH 2 )(OR F9 ) 2 (C 2 H 4 ), analogous OR F6 (OCMe(CF 3 ) 2 ) and OR F3 (OCMe 2 (CF 3 )) complexes are relatively stable at 22 °C.

Maji, Milan [University of California, Riverside, ↗
DOE OSTI2020

First-principles study of hydrogen behavior near W/WC interfaces

Hydrogen (H) solution, migration, and binding to vacancies near the tungsten/tungsten carbide (W/WC) interfaces based on hcp WC or bcc W (W/WCb and Wb/WC) have been studied by first-principles simulations to provide insights into the effect of C on H behavior in W exposed to C deposition in fusion reactors. The H behavior near the W/WC interfaces is related to the tensile or compressive strain due to the lattice match and interfacial effects. Near the W/WCb interface, the H solution energy in hcp WC increases approaching the interface, while it decreases from the W side to the interface. The configuration change of the W slab significantly decreases the H solution energy but has only a modest effect on the H migration energy barrier in comparison with the values in bcc W. The interface enhances the H binding to vacancies in WC layers. Both the interface and configuration adjustment of the W slab reduce the H binding to vacancies on the W side of the interface. Near the Wb/WC interface, H solution energies in both WC and W slabs weakly decrease approaching the interface. The configuration change of the WC slab significantly increases the H solution energy and binding energy to vacancies but decreases the H migration energy barrier in comparison with the values in hcp WC. The H energetics near the W/WC interfaces indicate the likelihood of H localization and diffusion in the W side of the interface, rather than diffusing through the interface into WC layers.

Yang, L. (ORCID:0000000322166071)↗
DOE OSTI2025

Temperature effects of ion irradiation on the nanostructural features in ductile-phase-toughened tungsten composites

Ductile-phase toughened tungsten (DPT W) composites have emerged as promising candidates for load-bearing components behind the plasma-facing tungsten armor in fusion reactors due to their enhanced thermomechanical properties. This study focuses on a composite consisting of W particles embedded in a ductile NiFeW solution matrix, hot-rolled to a thickness reduction of 87% (87R DPT W). Sequential irradiations with Ni2+ and He+ ions were performed to identical doses and helium concentrations at room temperature (RT) and 1273 K. Irradiation at RT produced no discernible nanostructural features due to the immobility of mono-vacancies, whereas cavity formation was observed at 973 K. At 1273 K, the W phase exhibited larger cavities, reduced cavity number density, and lower volumetric swelling compared to 973 K. Notably, nanosized NiFeW precipitates formed within the W phase at 1273 K, a phenomenon absent at 973 K. A new phase of cubic (NiFe)6W6C was also observed at the interphase boundary. In contrast, the NiFeW matrix showed no nanostructural changes at 1273 K, likely due to cavity dissociation. Separate irradiations at 1273 K indicated that Ni2+ ions induced precipitate formation in the W phase, while He+ ions exclusively caused cavity formation. The microstructure of 87R DPT W irradiated at RT and subsequently annealed at 1273 K closely resembled that of material irradiated directly at 1273 K. Like oxide-dispersion-strengthened steels, the observed nanoparticle-embedded W can inhibit dislocation propagation, potentially delaying the ductile-to-brittle transition temperature. These findings highlight the potential of NiFeW nanoparticle-reinforced W composites as irradiation-resistant materials for fusion reactors.

Jiang, Weilin (ORCID:0000000183028313)↗
DOE OSTI2024

Power and isotope effects in the ITER baseline scenario with tungsten and tungsten-equivalent radiators in DIII-D

Abstract Experiments in DIII-D document the ITER Baseline Scenario (IBS) at q 95 ∼ 3 and P IN / P LH ∼ 1–2, in both deuterium and hydrogen utilizing Kr and Xe as Tungsten-equivalent radiators. The power threshold for H-mode operation ( P LH ) was determined experimentally without added impurities and found to be about a factor of two higher than the scaling law. In recent IBS experiments in deuterium, intrinsic levels of metals such as Tungsten (W) or molybdenum and inconel are present that reduce the pedestal pressure by 20%–25%. A complete radiative collapse of deuterium IBS plasmas occurs at W core concentrations C W = 10 −5 . Simulations show that for core temperatures expected for ITER, the plasmas would not have a radiative collapse at C W = 1 × 10 −5 , moreover Q = 8–10 would still be achieved for C W up to 3 × 10 −5 . In contrast to deuterium, the IBS in hydrogen is not affected by intrinsic high-Z impurities, indicating that hydrogen H-modes in ITER may not inform the D-T phase with respect to W accumulation and discharge survival. Compared to deuterium, the pedestal pressure in hydrogen is ∼25% lower, with much higher ELM frequency of 150 Hz, decreasing with input power. Krypton was injected in a matrix scan of input power and impurity flow in IBS hydrogen discharges. Krypton impurity density profiles in hydrogen are similar to deuterium plasmas, but at Kr flows that are 2–3 times higher for the same input power. Krypton is transported into the core and affects the whole radius; at the highest injection rates a radiative collapse occurs at core radiation fractions of 0.3–0.35, consistent with the expected maximum W radiation fraction for ITER core plasmas. Comparing the results with previous International Tokamak Physics Activity database studies of the IBS confirms that at higher radiation fraction due to high-Z impurities, a drop in H 98 of >10% is observed. On the other hand, the results using Kr as a W-equivalent radiator indicate that metal (W) devices at lower core temperatures than ITER may provide overly pessimistic performance extrapolations to ITER for deuterium-tritium operation. The new DIII-D results support a more attractive option for the ITER Research Plan with a short hydrogen phase for system commissioning, transitioning to deuterium operations as soon as possible to provide relevant conditions for deuterium-tritium operations.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
NASA NTRS1994

Photoevaporation of disks around massive stars and application to ultracompact H II regions

Young massive stars produce sufficient Lyman continuum photon luminosity Phi(sub i) to significantly affect the structure and evolution of the accretion disks surrounding them. A nearly static, ionized, isothermal 10(exp 4) K atmosphere forms above the neutral disk for disk radii r less than r(sub g) = 10(exp 15) M(sub 1) cm, where M(sub *) = 10 solar mass M(sub 1) is the stellar mass. For r approximately greater than r(sub g) the diffuse field created by hydrogen recombinations to the ground state in the photoionized gas above the disk produces a steady evaporation at the surface of the disk, and this H II gas flows freely out to the ISM (the 'disk wind'). The detailed structure depends on the mass-loss rate dot-M(sub w) of the fast, approximately greater than 1000 km/sec, stellar wind from the massive star. A critical mass-loss rate dot-M(sub cr) is defined such that the ram pressure of the stellar wind equals the thermal pressure of the H II atmosphere at r(sub g). In the weak stellar wind solution, dot-M(sub w) less than dot-M(sub cr), the diffuse photons from the atmosphere above r(sub g) produce a photoevaporative mass-loss rate from the disk at r approximately greater than r(sub g) of order 1 x 10(exp -5)(Phi(sub 49))(exp 1/2)(M(sub 1))(exp 1/2) solar mass/year, where Phi(sub i) = 10(exp 49) Phi(sub 49)/sec. The resulting slow (10 to 50 km/sec) ionized outflow, which persists for approximately greater than 10(exp 5) year for disk masses M(sub d) approximately 0.3 M(sub *), may explain the observational characteri stics of unresolved, ultracompact H II regions. In the strong stellar wind solution, dot-M(sub w) greater than dot-M(sub cr), the ram pressure of the stellar wind blows down the atmosphere for r less than r(sub g) and allows the stellar photons to penetrate to greater radii and smaller heights. A slow, ionized outflow produced mainly by diffuse photons is again created for r less than r(sub g); however, it is now dominated by the flow at r(sub w)(greater than r(sub g)), the radius at which the stellar wind ram pressure equals the thermal pressure in the evaporating flow. The mass-loss rate from the disk is of order 6 x 10(exp -5)dot-M(sub w-6) v(sub w8)(Phi (sub 49))(exp -1/2) solar mass/year, where dot-M(sub w-6) = M(sub w)/10(exp -6) solar mass/year and v(sub w8) = v(sub w)/1000 km/sec is the stellar wind velocity. The resulting outflow, which also persists for approximately greater than 10(exp 5) year may explain many of the more extended (r approximately greater than 10(exp 16) cm) ultracompact H II regions. Both the weak-wind and the strong-wind models depend entirely on stellar parameters Phi(sub i), M(sub *), dot-M(sub w)) and are independent of disk parameters as long as an extended r much greater than (r(sub g)), neutral disk exists. We compare both weak-wind and strong-wind model results to the observed radio free-free spectra and luminosities of ultracompact H II regions and to the interesting source MWC 349.

Hollenbach, David↗