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DOE OSTI2020

Materials Data on Ce2Te7Cl2O17 by Materials Project

Ce2Te7O17Cl2 crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. Ce4+ is bonded to eight O2- atoms to form distorted edge-sharing CeO8 hexagonal bipyramids. There are a spread of Ce–O bond distances ranging from 2.16–2.58 Å. There are four inequivalent Te4+ sites. In the first Te4+ site, Te4+ is bonded in a 4-coordinate geometry to four O2- atoms. There are two shorter (1.90 Å) and two longer (2.13 Å) Te–O bond lengths. In the second Te4+ site, Te4+ is bonded in a 4-coordinate geometry to four O2- and one Cl1- atom. There are a spread of Te–O bond distances ranging from 1.89–2.30 Å. The Te–Cl bond length is 3.29 Å. In the third Te4+ site, Te4+ is bonded in a 4-coordinate geometry to four O2- and one Cl1- atom. There are a spread of Te–O bond distances ranging from 1.89–2.26 Å. The Te–Cl bond length is 3.36 Å. In the fourth Te4+ site, Te4+ is bonded in a 4-coordinate geometry to four O2- and one Cl1- atom. There are a spread of Te–O bond distances ranging from 1.88–2.42 Å. The Te–Cl bond length is 3.33 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Ce4+ and two Te4+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ce4+ and one Te4+ atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent Te4+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two Te4+ atoms. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Ce4+ and two Te4+ atoms. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Ce4+ and two Te4+ atoms. In the seventh O2- site, O2- is bonded in a linear geometry to one Ce4+ and one Te4+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Ce4+ and two Te4+ atoms. In the ninth O2- site, O2- is bonded in a linear geometry to one Ce4+ and one Te4+ atom. Cl1- is bonded in a 3-coordinate geometry to three Te4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ag32Te20As3 by Materials Project

Ag32As3Te20 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. there are four inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to two equivalent Ag1+ and four equivalent Te2- atoms. Both Ag–Ag bond lengths are 2.94 Å. All Ag–Te bond lengths are 3.31 Å. In the second Ag1+ site, Ag1+ is bonded in a 8-coordinate geometry to five Ag1+ and three Te2- atoms. There are a spread of Ag–Ag bond distances ranging from 2.86–3.05 Å. There are two shorter (2.97 Å) and one longer (3.21 Å) Ag–Te bond lengths. In the third Ag1+ site, Ag1+ is bonded in a 3-coordinate geometry to two equivalent Ag1+ and three Te2- atoms. There are one shorter (2.86 Å) and two longer (2.90 Å) Ag–Te bond lengths. In the fourth Ag1+ site, Ag1+ is bonded in a distorted single-bond geometry to one Ag1+ and six equivalent Te2- atoms. The Ag–Ag bond length is 2.69 Å. All Ag–Te bond lengths are 4.03 Å. As+2.67+ is bonded in a square co-planar geometry to four equivalent Te2- atoms. All As–Te bond lengths are 2.80 Å. There are three inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a distorted pentagonal pyramidal geometry to six equivalent Ag1+ atoms. In the second Te2- site, Te2- is bonded in a 8-coordinate geometry to four Ag1+ and four Te2- atoms. There are two shorter (2.75 Å) and two longer (3.26 Å) Te–Te bond lengths. In the third Te2- site, Te2- is bonded in a 8-coordinate geometry to six Ag1+, one As+2.67+, and one Te2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y5(NiTe)2 by Materials Project

Y5(NiTe)2 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are three inequivalent Y sites. In the first Y site, Y is bonded in a 7-coordinate geometry to three Ni and four equivalent Te atoms. There are two shorter (2.86 Å) and one longer (2.91 Å) Y–Ni bond lengths. There are two shorter (3.34 Å) and two longer (3.37 Å) Y–Te bond lengths. In the second Y site, Y is bonded in a 6-coordinate geometry to three Ni and three equivalent Te atoms. There are two shorter (2.85 Å) and one longer (2.97 Å) Y–Ni bond lengths. There are one shorter (3.15 Å) and two longer (3.24 Å) Y–Te bond lengths. In the third Y site, Y is bonded in a square co-planar geometry to two Ni and two equivalent Te atoms. There are one shorter (2.91 Å) and one longer (3.17 Å) Y–Ni bond lengths. Both Y–Te bond lengths are 3.17 Å. There are two inequivalent Ni sites. In the first Ni site, Ni is bonded in a 9-coordinate geometry to seven Y and two equivalent Ni atoms. Both Ni–Ni bond lengths are 2.50 Å. In the second Ni site, Ni is bonded in a 9-coordinate geometry to seven Y and two equivalent Ni atoms. Te is bonded in a 8-coordinate geometry to eight Y atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y5(CoTe)2 by Materials Project

Y5(CoTe)2 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are three inequivalent Y sites. In the first Y site, Y is bonded in a 7-coordinate geometry to three Co and four equivalent Te atoms. There are one shorter (2.83 Å) and two longer (2.84 Å) Y–Co bond lengths. There are two shorter (3.33 Å) and two longer (3.35 Å) Y–Te bond lengths. In the second Y site, Y is bonded in a 6-coordinate geometry to three Co and three equivalent Te atoms. There are two shorter (2.85 Å) and one longer (2.92 Å) Y–Co bond lengths. There are one shorter (3.15 Å) and two longer (3.20 Å) Y–Te bond lengths. In the third Y site, Y is bonded in a distorted square co-planar geometry to two Co and two equivalent Te atoms. There are one shorter (2.95 Å) and one longer (3.26 Å) Y–Co bond lengths. Both Y–Te bond lengths are 3.18 Å. There are two inequivalent Co sites. In the first Co site, Co is bonded in a 9-coordinate geometry to seven Y and two equivalent Co atoms. Both Co–Co bond lengths are 2.38 Å. In the second Co site, Co is bonded in a 9-coordinate geometry to seven Y and two equivalent Co atoms. Te is bonded in a 8-coordinate geometry to eight Y atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AgSb(Te8Pb7)2 by Materials Project

AgSb(Pb7Te8)2 is alpha Po-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ag1+ is bonded to six Te2- atoms to form AgTe6 octahedra that share corners with two equivalent PbTe6 octahedra, corners with four equivalent SbTe6 octahedra, and edges with twelve PbTe6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.98 Å) and four longer (3.36 Å) Ag–Te bond lengths. There are four inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded to six Te2- atoms to form a mixture of edge and corner-sharing PbTe6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (3.22 Å) and four longer (3.27 Å) Pb–Te bond lengths. In the second Pb2+ site, Pb2+ is bonded to six Te2- atoms to form PbTe6 octahedra that share corners with six PbTe6 octahedra, edges with two equivalent AgTe6 octahedra, edges with two equivalent SbTe6 octahedra, and edges with eight equivalent PbTe6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are two shorter (3.23 Å) and four longer (3.27 Å) Pb–Te bond lengths. In the third Pb2+ site, Pb2+ is bonded to six Te2- atoms to form PbTe6 octahedra that share corners with six equivalent PbTe6 octahedra, an edgeedge with one AgTe6 octahedra, an edgeedge with one SbTe6 octahedra, and edges with ten PbTe6 octahedra. The corner-sharing octahedra tilt angles range from 0–8°. There are a spread of Pb–Te bond distances ranging from 3.20–3.28 Å. In the fourth Pb2+ site, Pb2+ is bonded to six Te2- atoms to form PbTe6 octahedra that share a cornercorner with one AgTe6 octahedra, a cornercorner with one SbTe6 octahedra, corners with four equivalent PbTe6 octahedra, and edges with twelve PbTe6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (3.27 Å) and two longer (3.40 Å) Pb–Te bond lengths. Sb3+ is bonded to six Te2- atoms to form SbTe6 octahedra that share corners with two equivalent PbTe6 octahedra, corners with four equivalent AgTe6 octahedra, and edges with twelve PbTe6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (3.11 Å) and four longer (3.17 Å) Sb–Te bond lengths. There are six inequivalent Te2- sites. In the first Te2- site, Te2- is bonded to six Pb2+ atoms to form a mixture of edge and corner-sharing TePb6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the second Te2- site, Te2- is bonded to six Pb2+ atoms to form a mixture of edge and corner-sharing TePb6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the third Te2- site, Te2- is bonded to one Ag1+, four Pb2+, and one Sb3+ atom to form TeAgSbPb4 octahedra that share corners with six TePb6 octahedra and edges with twelve TeAgSbPb4 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the fourth Te2- site, Te2- is bonded to one Ag1+ and five Pb2+ atoms to form TeAgPb5 octahedra that share corners with six TeAgPb5 octahedra and edges with twelve TePb6 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. In the fifth Te2- site, Te2- is bonded to five Pb2+ and one Sb3+ atom to form TeSbPb5 octahedra that share corners with six TeAgPb5 octahedra and edges with twelve TePb6 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. In the sixth Te2- site, Te2- is bonded to one Ag1+, four Pb2+, and one Sb3+ atom to form TeAgSbPb4 octahedra that share corners with six TePb6 octahedra and edges with twelve TeAgSbPb4 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. Both Te–Pb bond lengths are 3.20 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K2TeO5 by Materials Project

K2TeO5 crystallizes in the orthorhombic Immm space group. The structure is two-dimensional and consists of two K2TeO5 sheets oriented in the (0, 0, 1) direction. there are three inequivalent K sites. In the first K site, K is bonded in a 6-coordinate geometry to four equivalent O atoms. All K–O bond lengths are 2.78 Å. In the second K site, K is bonded in a 4-coordinate geometry to four equivalent O atoms. All K–O bond lengths are 2.74 Å. In the third K site, K is bonded in a distorted T-shaped geometry to three O atoms. There are two shorter (2.57 Å) and one longer (2.60 Å) K–O bond lengths. Te is bonded to six O atoms to form edge-sharing TeO6 octahedra. There are a spread of Te–O bond distances ranging from 1.90–2.04 Å. There are five inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Te atom. In the second O site, O is bonded in a 1-coordinate geometry to three K and one Te atom. In the third O site, O is bonded in a water-like geometry to two equivalent Te atoms. In the fourth O site, O is bonded in a water-like geometry to two equivalent Te atoms. In the fifth O site, O is bonded in a bent 150 degrees geometry to one K and one Te atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ni(Te4Mo3)2 by Materials Project

Ni(Mo3Te4)2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Mo+2.33+ sites. In the first Mo+2.33+ site, Mo+2.33+ is bonded to five Te2- atoms to form MoTe5 square pyramids that share corners with four MoTe5 square pyramids, corners with two equivalent NiTe4 tetrahedra, and edges with five MoTe5 square pyramids. There are a spread of Mo–Te bond distances ranging from 2.73–2.90 Å. In the second Mo+2.33+ site, Mo+2.33+ is bonded to five Te2- atoms to form MoTe5 square pyramids that share corners with four MoTe5 square pyramids, corners with two equivalent NiTe4 tetrahedra, and edges with five MoTe5 square pyramids. There are a spread of Mo–Te bond distances ranging from 2.72–2.91 Å. In the third Mo+2.33+ site, Mo+2.33+ is bonded to five Te2- atoms to form distorted MoTe5 square pyramids that share corners with four MoTe5 square pyramids, a cornercorner with one NiTe4 tetrahedra, edges with five MoTe5 square pyramids, and a faceface with one NiTe4 tetrahedra. There are a spread of Mo–Te bond distances ranging from 2.73–2.97 Å. In the fourth Mo+2.33+ site, Mo+2.33+ is bonded to five Te2- atoms to form MoTe5 square pyramids that share corners with four MoTe5 square pyramids, corners with two equivalent NiTe4 tetrahedra, and edges with five MoTe5 square pyramids. There are a spread of Mo–Te bond distances ranging from 2.73–2.90 Å. In the fifth Mo+2.33+ site, Mo+2.33+ is bonded to five Te2- atoms to form MoTe5 square pyramids that share corners with four MoTe5 square pyramids, a cornercorner with one NiTe4 tetrahedra, edges with five MoTe5 square pyramids, and an edgeedge with one NiTe4 tetrahedra. There are a spread of Mo–Te bond distances ranging from 2.77–2.88 Å. In the sixth Mo+2.33+ site, Mo+2.33+ is bonded to five Te2- atoms to form MoTe5 square pyramids that share corners with four MoTe5 square pyramids, edges with five MoTe5 square pyramids, and an edgeedge with one NiTe4 tetrahedra. There are a spread of Mo–Te bond distances ranging from 2.77–2.87 Å. Ni2+ is bonded to four Te2- atoms to form NiTe4 tetrahedra that share corners with eight MoTe5 square pyramids, edges with two MoTe5 square pyramids, and a faceface with one MoTe5 square pyramid. There are a spread of Ni–Te bond distances ranging from 2.46–2.62 Å. There are eight inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 1-coordinate geometry to three Mo+2.33+ and one Ni2+ atom. In the second Te2- site, Te2- is bonded in a 4-coordinate geometry to three Mo+2.33+ atoms. In the third Te2- site, Te2- is bonded in a 1-coordinate geometry to four Mo+2.33+ and one Ni2+ atom. In the fourth Te2- site, Te2- is bonded in a 1-coordinate geometry to four Mo+2.33+ and one Ni2+ atom. In the fifth Te2- site, Te2- is bonded in a 4-coordinate geometry to four Mo+2.33+ atoms. In the sixth Te2- site, Te2- is bonded in a distorted rectangular see-saw-like geometry to four Mo+2.33+ atoms. In the seventh Te2- site, Te2- is bonded in a 1-coordinate geometry to four Mo+2.33+ and one Ni2+ atom. In the eighth Te2- site, Te2- is bonded in a 4-coordinate geometry to four Mo+2.33+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsMnInTe3 by Materials Project

CsMnInTe3 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 8-coordinate geometry to eight Te2- atoms. There are a spread of Cs–Te bond distances ranging from 3.90–4.56 Å. In the second Cs1+ site, Cs1+ is bonded in a 8-coordinate geometry to eight Te2- atoms. There are a spread of Cs–Te bond distances ranging from 3.90–4.57 Å. There are three inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to four Te2- atoms to form MnTe4 tetrahedra that share corners with four equivalent MnTe4 tetrahedra and corners with four InTe4 tetrahedra. There are two shorter (2.74 Å) and two longer (2.76 Å) Mn–Te bond lengths. In the second Mn2+ site, Mn2+ is bonded to four Te2- atoms to form MnTe4 tetrahedra that share corners with four MnTe4 tetrahedra and corners with four InTe4 tetrahedra. There are two shorter (2.74 Å) and two longer (2.76 Å) Mn–Te bond lengths. In the third Mn2+ site, Mn2+ is bonded to four Te2- atoms to form MnTe4 tetrahedra that share corners with four equivalent MnTe4 tetrahedra and corners with four InTe4 tetrahedra. There are two shorter (2.74 Å) and two longer (2.76 Å) Mn–Te bond lengths. There are two inequivalent In3+ sites. In the first In3+ site, In3+ is bonded to four Te2- atoms to form InTe4 tetrahedra that share corners with two equivalent InTe4 tetrahedra and corners with four MnTe4 tetrahedra. There are two shorter (2.83 Å) and two longer (2.84 Å) In–Te bond lengths. In the second In3+ site, In3+ is bonded to four Te2- atoms to form InTe4 tetrahedra that share corners with two equivalent InTe4 tetrahedra and corners with four MnTe4 tetrahedra. There are a spread of In–Te bond distances ranging from 2.82–2.85 Å. There are six inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 3-coordinate geometry to two Cs1+, two Mn2+, and one In3+ atom. In the second Te2- site, Te2- is bonded in a 3-coordinate geometry to two Cs1+, two Mn2+, and one In3+ atom. In the third Te2- site, Te2- is bonded in a 4-coordinate geometry to four Cs1+ and two In3+ atoms. In the fourth Te2- site, Te2- is bonded in a 4-coordinate geometry to four Cs1+ and two In3+ atoms. In the fifth Te2- site, Te2- is bonded in a 3-coordinate geometry to two Cs1+, two Mn2+, and one In3+ atom. In the sixth Te2- site, Te2- is bonded in a 3-coordinate geometry to two Cs1+, two Mn2+, and one In3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ce2Te7Br2O17 by Materials Project

Ce2Te7O17Br2 crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. Ce4+ is bonded to eight O2- atoms to form distorted edge-sharing CeO8 hexagonal bipyramids. There are a spread of Ce–O bond distances ranging from 2.16–2.59 Å. There are four inequivalent Te4+ sites. In the first Te4+ site, Te4+ is bonded in a 4-coordinate geometry to four O2- and two equivalent Br1- atoms. There are a spread of Te–O bond distances ranging from 1.89–2.30 Å. There are one shorter (3.37 Å) and one longer (3.52 Å) Te–Br bond lengths. In the second Te4+ site, Te4+ is bonded in a 4-coordinate geometry to four O2- atoms. There are two shorter (1.91 Å) and two longer (2.13 Å) Te–O bond lengths. In the third Te4+ site, Te4+ is bonded in a 4-coordinate geometry to four O2- and two equivalent Br1- atoms. There are a spread of Te–O bond distances ranging from 1.89–2.26 Å. There are one shorter (3.41 Å) and one longer (3.47 Å) Te–Br bond lengths. In the fourth Te4+ site, Te4+ is bonded in a 4-coordinate geometry to four O2- and one Br1- atom. There are a spread of Te–O bond distances ranging from 1.88–2.45 Å. The Te–Br bond length is 3.42 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Ce4+ and two Te4+ atoms. In the second O2- site, O2- is bonded in a linear geometry to one Ce4+ and one Te4+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ce4+ and one Te4+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ce4+ and two Te4+ atoms. In the fifth O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent Te4+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two Te4+ atoms. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Ce4+ and two Te4+ atoms. In the eighth O2- site, O2- is bonded in a linear geometry to one Ce4+ and one Te4+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Ce4+ and two Te4+ atoms. Br1- is bonded in a 5-coordinate geometry to five Te4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hf2Te3 by Materials Project

Hf2Te3 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. there are three inequivalent Hf sites. In the first Hf site, Hf is bonded to six equivalent Te atoms to form a mixture of edge and corner-sharing HfTe6 octahedra. The corner-sharing octahedral tilt angles are 51°. All Hf–Te bond lengths are 2.89 Å. In the second Hf site, Hf is bonded to six equivalent Te atoms to form a mixture of face, edge, and corner-sharing HfTe6 octahedra. The corner-sharing octahedral tilt angles are 49°. There are three shorter (2.92 Å) and three longer (2.95 Å) Hf–Te bond lengths. In the third Hf site, Hf is bonded to six equivalent Te atoms to form a mixture of face and corner-sharing HfTe6 octahedra. The corner-sharing octahedra tilt angles range from 49–51°. All Hf–Te bond lengths are 2.90 Å. Te is bonded in a rectangular see-saw-like geometry to four Hf atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K7Na(TeO8)4 by Materials Project

K7Na(TeO8)4 crystallizes in the orthorhombic Immm space group. The structure is two-dimensional and consists of two K7Na(TeO8)4 sheets oriented in the (0, 1, 0) direction. there are four inequivalent K sites. In the first K site, K is bonded in a 8-coordinate geometry to eight O atoms. There are four shorter (2.69 Å) and four longer (3.10 Å) K–O bond lengths. In the second K site, K is bonded in a 8-coordinate geometry to eight O atoms. There are four shorter (2.67 Å) and four longer (2.75 Å) K–O bond lengths. In the third K site, K is bonded in a 6-coordinate geometry to two equivalent O atoms. Both K–O bond lengths are 2.72 Å. In the fourth K site, K is bonded in a hexagonal bipyramidal geometry to eight equivalent O atoms. All K–O bond lengths are 2.80 Å. Na is bonded in a linear geometry to two equivalent O atoms. Both Na–O bond lengths are 2.28 Å. Te is bonded to six O atoms to form edge-sharing TeO6 octahedra. There are a spread of Te–O bond distances ranging from 1.89–2.06 Å. There are seven inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Te atom. In the second O site, O is bonded in a 1-coordinate geometry to two K and one Te atom. In the third O site, O is bonded in a 4-coordinate geometry to three K and one O atom. The O–O bond length is 1.29 Å. In the fourth O site, O is bonded in a 1-coordinate geometry to two K and one O atom. The O–O bond length is 1.27 Å. In the fifth O site, O is bonded in a water-like geometry to two equivalent Te atoms. In the sixth O site, O is bonded in a distorted trigonal planar geometry to one Na and two equivalent Te atoms. In the seventh O site, O is bonded in a single-bond geometry to one Te atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Fe2Te4BrClO10 by Materials Project

Fe2Te4O10BrCl crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form distorted edge-sharing FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.95–2.34 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form edge-sharing FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.94–2.14 Å. There are four inequivalent Te4+ sites. In the first Te4+ site, Te4+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Te–O bond distances ranging from 1.88–2.00 Å. In the second Te4+ site, Te4+ is bonded in a 6-coordinate geometry to four O2- atoms. There are a spread of Te–O bond distances ranging from 1.93–2.59 Å. In the third Te4+ site, Te4+ is bonded in a 5-coordinate geometry to four O2- and one Br1- atom. There are a spread of Te–O bond distances ranging from 1.89–2.57 Å. The Te–Br bond length is 3.17 Å. In the fourth Te4+ site, Te4+ is bonded in a 2-coordinate geometry to two O2-, two equivalent Br1-, and one Cl1- atom. There is one shorter (1.88 Å) and one longer (1.92 Å) Te–O bond length. There are one shorter (3.25 Å) and one longer (3.31 Å) Te–Br bond lengths. The Te–Cl bond length is 2.39 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Fe3+ and one Te4+ atom. In the second O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Fe3+ and one Te4+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Fe3+ and one Te4+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe3+ and one Te4+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to three Te4+ atoms. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Te4+ atoms. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to one Fe3+ and one Te4+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Fe3+ and one Te4+ atom. In the ninth O2- site, O2- is bonded to three Fe3+ and one Te4+ atom to form distorted edge-sharing OFe3Te tetrahedra. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to one Fe3+ and one Te4+ atom. Br1- is bonded in a 3-coordinate geometry to three Te4+ atoms. Cl1- is bonded in a single-bond geometry to one Te4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Topological Antiferromagnetic Van der Waals Phase in Topological Insulator/Ferromagnet Heterostructures Synthesized by a CMOS-Compatible Sputtering Technique

Breaking time-reversal symmetry by introducing magnetic order, thereby opening a gap in the topological surface state bands, is essential for realizing useful topological properties such as the quantum anomalous Hall and axion insulator states. In this work, a novel topological antiferromagnetic (AFM) phase is created at the interface of a sputtered, c-axis-oriented, topological insulator/ferromagnet heterostructure—Bi 2 Te 3 /Ni 80 Fe 20 because of diffusion of Ni in Bi 2 Te 3 (Ni-Bi 2 Te 3 ). The AFM property of the Ni-Bi2Te3 interfacial layer is established by observation of spontaneous exchange bias in the magnetic hysteresis loop and compensated moments in the depth profile of the magnetization using polarized neutron reflectometry. Analysis of the structural and chemical properties of the Ni-Bi2Te3 layer is carried out using selected-area electron diffraction, electron energy loss spectroscopy, and X-ray photoelectron spectroscopy. These studies, in parallel with first-principles calculations, indicate a solid-state chemical reaction that leads to the formation of Ni=Te bonds and the presence of topological antiferromagnetic (AFM) compound NiBi 2 Te 4 in the Ni-Bi 2 Te 3 interface layer. The Neél temperature of the Ni-Bi 2 Te 3 layer is ≈ 63 K, which is higher than that of typical magnetic topological insulators (MTIs). The presented results provide a pathway toward industrial complementary metal-oxide-semiconductor (CMOS)-process-compatible sputtered-MTI heterostructures, leading to novel materials for topological quantum devices.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Corrosion property of Alloy 625 in Molten FLiNaK salt according to the Tellurium Concentrations

For this work, the corrosion properties of Alloy 625 have been studied in molten FLiNaK salt for 48 h at 700 °C as a function of tellurium (Te) concentrations using immersion tests and electrochemical methods. Under specific Te concentrations, we found that Te-induced corrosion can be suppressed and help protect the alloy against corrosion. The sample after the immersion test containing 0.1 wt.% Te (0.1 wt.% Te sample) had the lowest corrosion depth and mass loss, coupled with the highest charge transfer resistance, obtained using electrochemical impedance spectroscopy (EIS). On the other hand, the alloy with Te content above 0.1 wt.% exhibited severe corrosion penetration and lower charge transfer resistance in FLiNaK. Based on thermodynamical and electrochemical analyses, a corrosion mechanism of Alloy 625 in the molten salt containing Te was theorized involving the formation of stable corrosion products such as Ni/Fe rich layer depleted in Cr, nickel telluride, and chromium oxide.

Hong, Minsung↗
DOE OSTI2020

Coulomb blockade effects in a topological insulator grown on a high- T c cuprate superconductor

The evidence for proximity-induced superconductivity in heterostructures of topological insulators and high- T c cuprates has been intensely debated. We use molecular-beam epitaxy to grow thin films of topological insulator Bi 2 Te 3 on a cuprate Bi 2 Sr 2 CaCu 2 O 8+x , and study the surface of Bi 2 Te 3 using low-temperature scanning tunneling microscopy and spectroscopy. In few unit-cell thick Bi 2 Te 3 films, we find a V-shaped gap-like feature at the Fermi energy in d I /d V spectra. By reducing the coverage of Bi 2 Te 3 films to create nanoscale islands, we discover that this spectral feature dramatically evolves into a much larger hard gap, which can be understood as a Coulomb blockade gap. This conclusion is supported by the evolution of d I /d V spectra with the lateral size of Bi 2 Te 3 islands, as well as by topographic measurements that show an additional barrier separating Bi 2 Te 3 and Bi 2 Sr 2 CaCu 2 O 8+x . We conclude that the prominent gap-like feature in d I /d V spectra in Bi 2 Te 3 films is not a proximity-induced superconducting gap. Instead, it can be explained by Coulomb blockade effects, which take into account additional resistive and capacitive coupling at the interface. Our experiments provide a fresh insight into the tunneling measurements of complex heterostructures with buried interfaces.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2026

ZTF-SEDm Type Ia supernova sample for Twins Embedding spectrophotometric standardization

Aims. This paper has two aims: the first aim is to build a large homogeneous spectrophotometric sample of Type Ia supernovae (SNe Ia) from the second data release of the Zwicky Transient Facility (ZTF DR2). We used the spectrum sample from the low-resolution ( R ∼ 100) SEDmachine (SEDm) Integral Field Spectrograph (IFS) that gathered 3069 spectra. This is one of the largest samples of such collections that can attempt to reproduce the Twins Embedding (TE) spectrophotometric standardization method. This is our second objective. The method was developed based on high-quality spectra from 200 SNe Ia of the Nearby Supernova factory (SNfactory) and led to an exceptionally low value of 0.073 mag for the intrinsic scatter. Methods. As the SEDm is not designed as a spectrophotometric instrument, we first improved the flux-calibration accuracy of the SN Ia spectrum sample using the ZTF photometric data, which were calibrated at the percent level. We corrected the spectra for second-order polynomials, fitted by comparing the synthetic photometry in the ZTF g , r , i filters with the light-curve (LC) data. We then applied the three steps of the TE parameterization to a subset of 783 ZTF SN spectra near maximum light while comparing results from SNfactory and ZTF. We finally analyzed the standardization methods based on the TE parameters. Results. The precision of the phase-correction model, which is the first step of the TE, is estimated at 0.01 mag in g band based on ZTF data. Despite the challenge posed by the spectrum-extraction pipeline associated with the SEDm (flux calibration, leftover host signal, low signal-to-noise ratio, and low resolution), we applied a first standardization in color based on the second step of the TE, called read between the lines (RBTL), to the ZTF sample. We reached a Hubble residual scatter of 0.153 mag, all in normalized median absolute deviation, which is to be compared to the ∼0.11 mag obtained with the SNfactory data. The SALT color and stretch standardization reaches a scatter of 0.164 mag for the same ZTF SN Ia sample, and its host steps are ∼0.1 mag and zero for RBTL. When considering the scatter due to the redshift error and flux calibration error, we estimated a RBTL scatter of ∼0.129 mag for this ZTF sample as an upper limit because we identified an additional contribution from a systematic error in color. We tested the standardization based on the nonlinear TE parameters, and, as expected from the low spectrum quality, it did not improve the overall dispersion. Conclusions. We release 1897 flux calibrated spectra of 1607 SNe Ia with an estimated photometric accuracy of 0.07 mag. We further demonstrate that some amount of spectrophotometric SN Ia standardization can be done with limited-quality spectra. The RBTL standardization is more efficient than that of SALT with one parameter less, and the resulting host steps are consistent with zero. This makes it less prone to astrophysical bias. For future spectroscopic surveys, targeting the extraction pipeline for a thorough flux calibration and good signal-to-noise ratio would enable us to compute the full TE standardization, which would further reduce the scatter in the distance estimate.

Ganot, C↗
DOE OSTI2025

Coherently coupled carrier and phonon dynamics in elemental tellurium probed by extreme ultraviolet transient absorption

The narrow band-gap semiconductor elemental tellurium (Te) has a unique electronic structure due to strong spin-orbit splitting and a lack of inversion symmetry of its helical lattice. Using broadband extreme ultraviolet core-level transient absorption, we simultaneously measure the coherently coupled photoinduced carrier and lattice dynamics at the Te N4,5 edge initiated by a few-cycle NIR pulse. Ultrafast excitation of carriers leads to a coherently excited A1 phonon oscillation and the generation of a hot carrier population distribution that oscillates in temperature, and the phonon excursion and hot carrier temperature are π out of phase with respect to each other. The depths of modulation suggest a significant coupling between the electronic and lattice degrees of freedom in Te. A long-lived shift of the absorption edge suggests an excited state of Te in another equilibrium potential energy surface that lives on the order of the carrier recombination timescale. The observed phonon-induced oscillations of the hot carriers are supportive of a change in the metallicity, whereby Te becomes more metallic with increasing phonon-induced displacement. Additionally, near the Fermi level we observe an energy-dependent phase of the displacive excitation of the A1 phonon mode. The discovery of coherent coupling between the lattice and hot carriers in Te provides the basis to investigate coherent interactions between spin and orbital degrees of freedom. The results spectrally and temporally resolve the correlation between photoexcited hot carriers and coherent lattice excitations, providing insight on the optical manipulation of the Te electronic structure at high carrier densities exceeding 1021cm−3.

Adelman, Jonah R↗
DOE OSTI2020

Adsorption-controlled growth of MnTe(Bi2Te3)n by molecular beam epitaxy exhibiting stoichiometry-controlled magnetism

We report the growth of the intrinsic magnetic topological system MnTe ( Bi 2 Te 3 ) n by molecular beam epitaxy. By mapping the temperature and the Bi:Mn flux ratio, it is shown that there is a narrow growth window for the n = 1 phase Mn Bi 2 Te 4 with 2.0 < Bi : Mn < 2.6 at 225°C. In this work, the films are stoichiometric and excess Bi and Te is not incorporated. At higher flux ratios (Bi:Mn≥4.5) it is found that the n = 2 Mn Bi 4 Te 7 phase is stabilized. Transport measurements indicate that the Mn Bi 2 Te 4 and Mn Bi 4 Te 7 undergo magnetic transitions around 25 and 10 K, respectively, consistent with antiferromagnetic phases found in the bulk. Further, for Mn-rich conditions (Bi:Mn<2), ferromagnetism emerges that exhibits a clear hysteretic state in the Hall effect, which likely indicates Mn-doped Mn Bi 2 Te 4 . Understanding how to grow ternary chalcogenide phases is the key to synthesizing new materials and to interface magnetism and topology, which together are routes to realize and control exotic quantum phenomena.

36 MATERIALS SCIENCE↗