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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on NbFe(PbO3)2 by Materials Project

NbFe(PbO3)2 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal I4mm space group. The structure is three-dimensional. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six equivalent FeO6 octahedra and faces with eight equivalent PbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Nb–O bond distances ranging from 2.00–2.03 Å. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six equivalent NbO6 octahedra and faces with eight equivalent PbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Fe–O bond distances ranging from 2.01–2.06 Å. Pb2+ is bonded to twelve O2- atoms to form PbO12 cuboctahedra that share corners with twelve equivalent PbO12 cuboctahedra, faces with six equivalent PbO12 cuboctahedra, faces with four equivalent NbO6 octahedra, and faces with four equivalent FeO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.84–2.89 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to one Nb5+, one Fe3+, and four equivalent Pb2+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to one Nb5+, one Fe3+, and four equivalent Pb2+ atoms. In the third O2- site, O2- is bonded in a linear geometry to one Nb5+, one Fe3+, and four equivalent Pb2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NbFe(PbO3)2 by Materials Project

NbFe(PbO3)2 is (Cubic) Perovskite-derived structured and crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with four equivalent NbO6 octahedra, and faces with eight PbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Nb–O bond distances ranging from 1.99–2.03 Å. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four equivalent FeO6 octahedra, and faces with eight PbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Fe–O bond distances ranging from 2.03–2.07 Å. There are two inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded to twelve O2- atoms to form PbO12 cuboctahedra that share corners with twelve PbO12 cuboctahedra, faces with six PbO12 cuboctahedra, faces with four equivalent NbO6 octahedra, and faces with four equivalent FeO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.70–3.04 Å. In the second Pb2+ site, Pb2+ is bonded to twelve O2- atoms to form distorted PbO12 cuboctahedra that share corners with twelve PbO12 cuboctahedra, faces with six PbO12 cuboctahedra, faces with four equivalent NbO6 octahedra, and faces with four equivalent FeO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.66–3.09 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to two equivalent Nb5+ and four Pb2+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to two equivalent Fe3+ and four Pb2+ atoms. In the third O2- site, O2- is bonded in a linear geometry to two equivalent Nb5+ and four Pb2+ atoms. In the fourth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Fe3+ and four Pb2+ atoms. In the fifth O2- site, O2- is bonded in a linear geometry to one Nb5+, one Fe3+, and four equivalent Pb2+ atoms. In the sixth O2- site, O2- is bonded in a distorted linear geometry to one Nb5+, one Fe3+, and four equivalent Pb2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NbFe by Materials Project

FeNb is Frank-Kasper $\mu$ Phase-like structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are seven inequivalent Nb sites. In the first Nb site, Nb is bonded in a 10-coordinate geometry to seven Nb and nine equivalent Fe atoms. There are a spread of Nb–Nb bond distances ranging from 2.80–2.96 Å. There are three shorter (2.90 Å) and six longer (3.00 Å) Nb–Fe bond lengths. In the second Nb site, Nb is bonded in a 6-coordinate geometry to four Nb and twelve Fe atoms. There are one shorter (2.72 Å) and three longer (2.95 Å) Nb–Nb bond lengths. There are a spread of Nb–Fe bond distances ranging from 2.76–2.93 Å. In the third Nb site, Nb is bonded in a 8-coordinate geometry to eight Nb and six equivalent Fe atoms. There are one shorter (2.64 Å) and six longer (3.14 Å) Nb–Nb bond lengths. All Nb–Fe bond lengths are 2.69 Å. In the fourth Nb site, Nb is bonded in a 8-coordinate geometry to eight Nb and six equivalent Fe atoms. All Nb–Nb bond lengths are 3.13 Å. All Nb–Fe bond lengths are 2.71 Å. In the fifth Nb site, Nb is bonded in a 6-coordinate geometry to nine Nb and six Fe atoms. All Nb–Nb bond lengths are 2.84 Å. All Nb–Fe bond lengths are 2.82 Å. In the sixth Nb site, Nb is bonded in a 6-coordinate geometry to nine Nb and six Fe atoms. There are three shorter (2.78 Å) and three longer (2.83 Å) Nb–Fe bond lengths. In the seventh Nb site, Nb is bonded to six equivalent Nb and six equivalent Fe atoms to form distorted NbNb6Fe6 cuboctahedra that share corners with twelve equivalent FeNb8Fe4 cuboctahedra, edges with six equivalent NbNb6Fe6 cuboctahedra, and faces with eighteen equivalent FeNb8Fe4 cuboctahedra. All Nb–Fe bond lengths are 2.57 Å. There are three inequivalent Fe sites. In the first Fe site, Fe is bonded to seven Nb and five Fe atoms to form FeNb7Fe5 cuboctahedra that share corners with fifteen FeNb7Fe5 cuboctahedra, edges with five FeNb8Fe4 cuboctahedra, and faces with thirteen FeNb7Fe5 cuboctahedra. There are one shorter (2.44 Å) and four longer (2.46 Å) Fe–Fe bond lengths. In the second Fe site, Fe is bonded to eight Nb and four equivalent Fe atoms to form distorted FeNb8Fe4 cuboctahedra that share corners with two equivalent NbNb6Fe6 cuboctahedra, corners with thirteen FeNb7Fe5 cuboctahedra, edges with five FeNb8Fe4 cuboctahedra, faces with three equivalent NbNb6Fe6 cuboctahedra, and faces with ten equivalent FeNb8Fe4 cuboctahedra. There are two shorter (2.41 Å) and two longer (2.52 Å) Fe–Fe bond lengths. In the third Fe site, Fe is bonded to six equivalent Nb and six equivalent Fe atoms to form FeNb6Fe6 cuboctahedra that share corners with twelve equivalent FeNb7Fe5 cuboctahedra, edges with six equivalent FeNb6Fe6 cuboctahedra, and faces with eighteen equivalent FeNb7Fe5 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NbFe(PO4)2 by Materials Project

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

36 MATERIALS SCIENCE↗
DOE OSTI2020

Absolute crystal and magnetic chiralities in the langasite compound Ba 3 NbFe 3 Si 2 O 14 determined by polarized neutron and x-ray scattering

Here, we present a combined polarized neutron and x-ray scattering study on two enantiopure langasite single crystals aimed at the determination of their absolute structural and magnetic chiralities and the coupling between them. Our respective data sets unambiguously reveal two samples of opposite structural chirality, where the magnetic handedness is pinned by the structural one. Simple energy considerations of the magnetic exchange and single-ion anisotropy parameters reveal that it is not the Dzyaloshinskii-Moriya interaction but the local single-ion anisotropy on a triangular plaquette which plays a key role in stabilizing one of the two magnetic helices.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗