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At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Ba(AgSn)2 by Materials Project

Ba(AgSn)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ba is bonded in a 8-coordinate geometry to eight equivalent Ag and eight equivalent Sn atoms. All Ba–Ag bond lengths are 3.79 Å. All Ba–Sn bond lengths are 3.77 Å. Ag is bonded in a 12-coordinate geometry to four equivalent Ba and four equivalent Sn atoms. All Ag–Sn bond lengths are 2.84 Å. Sn is bonded in a 9-coordinate geometry to four equivalent Ba, four equivalent Ag, and one Sn atom. The Sn–Sn bond length is 2.92 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(FeO2)4 by Materials Project

Ba(FeO2)4 crystallizes in the trigonal P-31m space group. The structure is two-dimensional and consists of one Ba(FeO2)4 sheet oriented in the (0, 0, 1) direction. Ba is bonded to twelve O atoms to form BaO12 cuboctahedra that share edges with six equivalent BaO12 cuboctahedra and edges with twelve equivalent FeO4 tetrahedra. There are six shorter (2.98 Å) and six longer (3.25 Å) Ba–O bond lengths. Fe is bonded to four O atoms to form FeO4 tetrahedra that share corners with four equivalent FeO4 tetrahedra and edges with three equivalent BaO12 cuboctahedra. There is three shorter (1.86 Å) and one longer (1.87 Å) Fe–O bond length. There are two inequivalent O sites. In the first O site, O is bonded in a linear geometry to three equivalent Ba and two equivalent Fe atoms. In the second O site, O is bonded in a distorted bent 120 degrees geometry to one Ba and two equivalent Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(GeAu)2 by Materials Project

Ba(AuGe)2 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Ba is bonded in a 8-coordinate geometry to eight equivalent Au and eight equivalent Ge atoms. There are four shorter (3.53 Å) and four longer (3.59 Å) Ba–Au bond lengths. All Ba–Ge bond lengths are 3.60 Å. Au is bonded in a 4-coordinate geometry to four equivalent Ba and four equivalent Ge atoms. There are two shorter (2.70 Å) and two longer (2.74 Å) Au–Ge bond lengths. Ge is bonded in a 9-coordinate geometry to four equivalent Ba and four equivalent Au atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(MgIn)2 by Materials Project

Ba(MgIn)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ba is bonded in a 8-coordinate geometry to eight equivalent Mg and eight equivalent In atoms. All Ba–Mg bond lengths are 4.00 Å. All Ba–In bond lengths are 3.75 Å. Mg is bonded to four equivalent Ba and four equivalent In atoms to form a mixture of corner, edge, and face-sharing MgBa4In4 tetrahedra. All Mg–In bond lengths are 2.99 Å. In is bonded in a 9-coordinate geometry to four equivalent Ba, four equivalent Mg, and one In atom. The In–In bond length is 2.90 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(ClO)2 by Materials Project

(BaO2Cl)2Cl2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional and consists of four hydrochloric acid molecules and one BaO2Cl framework. In the BaO2Cl framework, Ba is bonded in a 4-coordinate geometry to four O and three equivalent Cl atoms. There are a spread of Ba–O bond distances ranging from 2.72–2.81 Å. There are a spread of Ba–Cl bond distances ranging from 3.24–3.33 Å. There are two inequivalent O sites. In the first O site, O is bonded in a distorted bent 120 degrees geometry to two equivalent Ba and one Cl atom. The O–Cl bond length is 2.41 Å. In the second O site, O is bonded in a distorted bent 120 degrees geometry to two equivalent Ba atoms. Cl is bonded to three equivalent Ba and one O atom to form a mixture of distorted corner and edge-sharing ClBa3O trigonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(AlGa)2 by Materials Project

Ba(GaAl)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ba is bonded in a 8-coordinate geometry to eight equivalent Ga and eight equivalent Al atoms. All Ba–Ga bond lengths are 3.49 Å. All Ba–Al bond lengths are 3.62 Å. Ga is bonded in a 9-coordinate geometry to four equivalent Ba, one Ga, and four equivalent Al atoms. The Ga–Ga bond length is 2.75 Å. All Ga–Al bond lengths are 2.69 Å. Al is bonded to four equivalent Ba and four equivalent Ga atoms to form a mixture of distorted corner, edge, and face-sharing AlBa4Ga4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(BrO)2 by Materials Project

Ba(OBr)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Ba is bonded in a 10-coordinate geometry to four equivalent O and six equivalent Br atoms. There are two shorter (2.80 Å) and two longer (2.87 Å) Ba–O bond lengths. There are a spread of Ba–Br bond distances ranging from 3.37–3.48 Å. O is bonded in a distorted bent 120 degrees geometry to two equivalent Ba and two equivalent Br atoms. Both O–Br bond lengths are 2.62 Å. Br is bonded in a 1-coordinate geometry to three equivalent Ba and two equivalent O atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(BiS2)2 by Materials Project

Ba(BiS2)2 crystallizes in the hexagonal P-6 space group. The structure is three-dimensional. there are five inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine S2- atoms. There are six shorter (3.29 Å) and three longer (3.59 Å) Ba–S bond lengths. In the second Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine S2- atoms. There are six shorter (3.29 Å) and three longer (3.59 Å) Ba–S bond lengths. In the third Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine S2- atoms. There are three shorter (3.25 Å) and six longer (3.54 Å) Ba–S bond lengths. In the fourth Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.23–3.33 Å. In the fifth Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.23–3.33 Å. There are six inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to five S2- atoms to form distorted BiS5 square pyramids that share corners with four BiS6 octahedra, an edgeedge with one BiS6 octahedra, and edges with two equivalent BiS5 square pyramids. The corner-sharing octahedra tilt angles range from 5–87°. There are a spread of Bi–S bond distances ranging from 2.58–3.02 Å. In the second Bi3+ site, Bi3+ is bonded to five S2- atoms to form distorted BiS5 square pyramids that share corners with four BiS6 octahedra, an edgeedge with one BiS6 octahedra, and edges with two equivalent BiS5 square pyramids. The corner-sharing octahedra tilt angles range from 5–87°. There are a spread of Bi–S bond distances ranging from 2.59–3.02 Å. In the third Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with four BiS5 square pyramids, edges with four BiS6 octahedra, and an edgeedge with one BiS5 square pyramid. There are a spread of Bi–S bond distances ranging from 2.70–3.00 Å. In the fourth Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with four BiS5 square pyramids, edges with four BiS6 octahedra, and an edgeedge with one BiS5 square pyramid. There are a spread of Bi–S bond distances ranging from 2.71–2.98 Å. In the fifth Bi3+ site, Bi3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing BiS6 octahedra. The corner-sharing octahedra tilt angles range from 56–64°. There are a spread of Bi–S bond distances ranging from 2.76–2.93 Å. In the sixth Bi3+ site, Bi3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing BiS6 octahedra. The corner-sharing octahedra tilt angles range from 56–64°. There are a spread of Bi–S bond distances ranging from 2.74–2.92 Å. There are twelve inequivalent S2- sites. In the first S2- site, S2- is bonded to two Ba2+ and three Bi3+ atoms to form distorted SBa2Bi3 trigonal bipyramids that share corners with ten SBa2Bi3 square pyramids, corners with four equivalent SBa2Bi3 trigonal bipyramids, edges with five SBaBi4 square pyramids, and edges with two equivalent SBa2Bi3 trigonal bipyramids. In the second S2- site, S2- is bonded to two Ba2+ and three Bi3+ atoms to form distorted SBa2Bi3 trigonal bipyramids that share corners with ten SBa2Bi3 square pyramids, corners with four equivalent SBa2Bi3 trigonal bipyramids, edges with five SBa4Bi square pyramids, and edges with two equivalent SBa2Bi3 trigonal bipyramids. In the third S2- site, S2- is bonded to one Ba2+ and three Bi3+ atoms to form distorted SBaBi3 tetrahedra that share corners with four SBa2Bi3 square pyramids, corners with four equivalent SBaBi3 tetrahedra, corners with three SBa2Bi3 trigonal bipyramids, and an edgeedge with one SBa2Bi3 square pyramid. In the fourth S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Ba2+ and three Bi3+ atoms. In the fifth S2- site, S2- is bonded to two equivalent Ba2+ and three Bi3+ atoms to form distorted SBa2Bi3 square pyramids that share corners with two equivalent SBa4Bi square pyramids, corners with two equivalent SBaBi3 tetrahedra, corners with five SBa2Bi3 trigonal bipyramids, edges with five SBa2Bi3 square pyramids, an edgeedge with one SBaBi3 tetrahedra, and edges with three SBa2Bi3 trigonal bipyramids. In the sixth S2- site, S2- is bonded to two equivalent Ba2+ and three Bi3+ atoms to form distorted SBa2Bi3 square pyramids that share corners with two equivalent SBa4Bi square pyramids, corners with two equivalent SBaBi3 tetrahedra, corners with five SBa2Bi3 trigonal bipyramids, edges with five SBa2Bi3 square pyramids, and edges with three SBa2Bi3 trigonal bipyramids. In the seventh S2- site, S2- is bonded to two equivalent Ba2+ and three Bi3+ atoms to form distorted SBa2Bi3 trigonal bipyramids that share corners with eight SBa2Bi3 square pyramids, a cornercorner with one SBaBi3 tetrahedra, edges with five SBa2Bi3 square pyramids, and edges with four SBa2Bi3 trigonal bipyramids. In the eighth S2- site, S2- is bonded to two equivalent Ba2+ and three Bi3+ atoms to form distorted SBa2Bi3 trigonal bipyramids that share corners with eight SBa2Bi3 square pyramids, corners with two equivalent SBaBi3 tetrahedra, edges with five SBa2Bi3 square pyramids, and edges with four SBa2Bi3 trigonal bipyramids. In the ninth S2- site, S2- is bonded to one Ba2+ and four Bi3+ atoms to form a mixture of distorted edge and corner-sharing SBaBi4 square pyramids. In the tenth S2- site, S2- is bonded to one Ba2+ and four Bi3+ atoms to form a mixture of distorted edge and corner-sharing SBaBi4 square pyramids. In the eleventh S2- site, S2- is bonded to four Ba2+ and one Bi3+ atom to form distorted SBa4Bi square pyramids that share corners with six SBa4Bi square pyramids, corners with four SBa2Bi3 trigonal bipyramids, edges with seven SBa2Bi3 square pyramids, and edges with five SBa2Bi3 trigonal bipyramids. In the twelfth S2- site, S2- is bonded to four Ba2+ and one Bi3+ atom to form a mixture of distorted edge and corner-sharing SBa4Bi square pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(As2O7)2 by Materials Project

Ba(As2O7)2 crystallizes in the orthorhombic Pmna space group. The structure is three-dimensional. Ba is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Ba–O bond distances ranging from 2.83–2.89 Å. There are two inequivalent As sites. In the first As site, As is bonded to six O atoms to form AsO6 octahedra that share corners with two equivalent AsO4 tetrahedra and an edgeedge with one AsO6 octahedra. There are a spread of As–O bond distances ranging from 1.80–1.93 Å. In the second As site, As is bonded to four O atoms to form corner-sharing AsO4 tetrahedra. The corner-sharing octahedral tilt angles are 66°. There are a spread of As–O bond distances ranging from 1.72–1.75 Å. There are five inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to two As atoms. In the second O site, O is bonded in a distorted single-bond geometry to one Ba and one As atom. In the third O site, O is bonded in a distorted single-bond geometry to one Ba and one As atom. In the fourth O site, O is bonded in a water-like geometry to two equivalent As atoms. In the fifth O site, O is bonded in a distorted single-bond geometry to one Ba and one As atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(ZnSi)2 by Materials Project

Ba(ZnSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ba is bonded in a 8-coordinate geometry to eight equivalent Zn and eight equivalent Si atoms. All Ba–Zn bond lengths are 3.42 Å. All Ba–Si bond lengths are 3.43 Å. Zn is bonded in a 4-coordinate geometry to four equivalent Ba and four equivalent Si atoms. All Zn–Si bond lengths are 2.62 Å. Si is bonded in a 9-coordinate geometry to four equivalent Ba, four equivalent Zn, and one Si atom. The Si–Si bond length is 2.49 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(MoSe)3 by Materials Project

Ba(MoSe)3 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. Ba is bonded in a 9-coordinate geometry to nine Se atoms. There are a spread of Ba–Se bond distances ranging from 3.43–3.49 Å. There are three inequivalent Mo sites. In the first Mo site, Mo is bonded in a distorted see-saw-like geometry to four Se atoms. There are a spread of Mo–Se bond distances ranging from 2.68–2.75 Å. In the second Mo site, Mo is bonded in a distorted see-saw-like geometry to four Se atoms. There are a spread of Mo–Se bond distances ranging from 2.68–2.75 Å. In the third Mo site, Mo is bonded in a distorted see-saw-like geometry to four Se atoms. There are two shorter (2.68 Å) and two longer (2.74 Å) Mo–Se bond lengths. There are three inequivalent Se sites. In the first Se site, Se is bonded to three equivalent Ba and four Mo atoms to form a mixture of distorted corner, edge, and face-sharing SeBa3Mo4 hexagonal pyramids. In the second Se site, Se is bonded to three equivalent Ba and four Mo atoms to form a mixture of distorted corner, edge, and face-sharing SeBa3Mo4 hexagonal pyramids. In the third Se site, Se is bonded to three equivalent Ba and four Mo atoms to form a mixture of distorted corner, edge, and face-sharing SeBa3Mo4 hexagonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(ZnGe)2 by Materials Project

Ba(ZnGe)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ba is bonded in a 8-coordinate geometry to eight equivalent Zn and eight equivalent Ge atoms. All Ba–Zn bond lengths are 3.52 Å. All Ba–Ge bond lengths are 3.50 Å. Zn is bonded to four equivalent Ba and four equivalent Ge atoms to form a mixture of distorted face, edge, and corner-sharing ZnBa4Ge4 tetrahedra. All Zn–Ge bond lengths are 2.66 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Ba, four equivalent Zn, and one Ge atom. The Ge–Ge bond length is 2.65 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(InCu)2 by Materials Project

Ba(CuIn)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ba is bonded in a 8-coordinate geometry to eight equivalent Cu and eight equivalent In atoms. All Ba–Cu bond lengths are 3.47 Å. All Ba–In bond lengths are 3.71 Å. Cu is bonded in a 9-coordinate geometry to four equivalent Ba, one Cu, and four equivalent In atoms. The Cu–Cu bond length is 2.66 Å. All Cu–In bond lengths are 2.78 Å. In is bonded to four equivalent Ba and four equivalent Cu atoms to form a mixture of distorted corner, edge, and face-sharing InBa4Cu4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(CdGe)2 by Materials Project

Ba(CdGe)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ba is bonded in a 8-coordinate geometry to eight equivalent Cd and eight equivalent Ge atoms. All Ba–Cd bond lengths are 3.75 Å. All Ba–Ge bond lengths are 3.61 Å. Cd is bonded to four equivalent Ba and four equivalent Ge atoms to form a mixture of distorted face, edge, and corner-sharing CdBa4Ge4 tetrahedra. All Cd–Ge bond lengths are 2.87 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Ba, four equivalent Cd, and one Ge atom. The Ge–Ge bond length is 2.60 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Unravelling the sintering temperature-induced phase transformations in Ba(Fe 0.7 Ta 0.3 )O 3-δ ceramics

This work reports on the fundamental details of the crystal structure and phase transformations in Ba(Fe 0.7 Ta 0.3 )O 3-δ , the best known temperature-independent oxygen-sensing ceramic material for applications in extreme environments. Ba(Fe 0.7 Ta 0.3 )O 3-δ ceramics were synthesized using conventional solid-state ceramic reaction under variable sintering temperatures (T s = 1200–1350 °C). Combined X-ray diffraction (XRD) and high-resolution transmission electron microscopy (TEM) measurements revealed the T s -induced phase transformations and their origin in Ba(Fe 0.7 Ta 0.3 )O 3-δ . Associated with phase transformations, pseudo-cubic (PC) reflections, such as {200} PC , {211} PC , and {220} PC , exhibited distinct anomalies with increasing T s . At T s = 1200 °C, Ba(Fe 0.7 Ta 0.3 )O 3-δ stabilized in mixed orthorhombic + rhombohedral phases (Amm2 + R3m). With increasing T s (≥1250 °C), Ba(Fe 0.7 Ta 0.3 )O 3-δ ceramics stabilized in tetragonal/rhombohedral [P4mm + R3m] mixed phases, while variations in the quantity of the respective phases were observed. Because both structure and crystal chemistry play key roles in achieving enhanced performance in chemical sensing and catalytic converters, detailed understanding of the phase transformations and crystal structure of Ba(Fe 0.7 Ta 0.3 )O 3-δ ceramics, as derived in this work, will be useful to develop chemical sensors with optimum performance for high-temperature and corrosive environments.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Proton surface exchange kinetics of perovskite triple conducting thin films for protonic ceramic electrolysis cells: BaPr 0.9 Y 0.1 O 3–δ (BPY) vs. Ba 1–x Co 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3–δ (BCFZY)

Protonic ceramic electrolysis cells (PCECs) are an attractive green H 2 production technology, given their intermediate-temperature operating range and ability to produce dry H 2 . However, PCECs will benefit from development of more efficient and durable “triple conducting” anodes where steam is split, H incorporated, and oxygen evolved. In this work, we evaluated the kinetics of the steam-splitting/H incorporation reaction on BaPr 0.9 Y 0.1 O 3–δ (BPY) in comparison to the benchmark Ba 1–x Co 0.4 Fe 0.4 Z r0.1 Y 0.1 O 3–δ (BCFZY) composition, replacing most of the transition metal elements (Co, Fe, Zr) with the lanthanide Pr. We prepared geometrically well-defined perovskite BPY and BCFZY thin films by pulsed laser deposition and performed simultaneous optical transmission relaxation and electrical conductivity relaxation measurements at 400–500 °C in 0.21 atm O 2 during switching of the steam partial pressure to isolate and compare their proton surface exchange coefficients (k). The k values of BPY were comparable to those of BCFZY and more stable over time. According to angle-resolved XPS and STEM-EDS mapping of FIB cross-sections, the surface of BPY exhibited Ba enrichment, Pr deficiency, and Si contamination. In contrast, BCFZY exhibited Ba deficiency throughout, no obvious surface segregation, and less Si contamination. The Ba segregation on the BPY film appears to have promoted steam splitting/H incorporation kinetics even though the more basic surface reacted with the acidic environmental SiO x H y . Faster kinetics observed on stoichiometric BCFZY vs. Ba-deficient BCFZY confirmed the benefit of a high A-site Ba concentration. This result contrasts with most work on perovskites applied in solid oxide electrolysis cell anodes, in which A-site segregation is considered deleterious for surface reaction kinetics.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Structure and phase transitions in niobium and tantalum derived nanoscale transition metal perovskites, Ba(Ti,MV)O3, M=Nb,Ta

The prospect of creating ferroelectric or high permittivity nanomaterials provides motivation for investigating complex transition metal oxides of the form Ba(Ti, MV)O3, where M = Nb or Ta. Solid state processing typically produces mixtures of crystalline phases, rarely beyond minimally doped Nb/Ta. Using a modified sol-gel method, we prepared single phase nanocrystals of Ba(Ti, M)O3. Compositional and elemental analysis puts the empirical formulas close to BaTi0.5Nb0.5O3−δ and BaTi0.5Ta0.5O3−δ. For both materials, a reversible temperature dependent phase transition (non-centrosymmetric to symmetric) is observed in the Raman spectrum in the region 533–583 K (260–310 °C); for Ba(Ti, Nb)O3, the onset is at 543 K (270 °C); and for Ba(Ti, Ta)O3, the onset is at 533 K (260 °C), which are comparable with 390–393 K (117–120 °C) for bulk BaTiO3. The crystal structure was resolved by examination of the powder x-ray diffraction and atomic pair distribution function (PDF) analysis of synchrotron total scattering data. It was postulated whether the structure adopted at the nanoscale was single or double perovskite. Double perovskites (A2B′B″O6) are characterized by the type and extent of cation ordering, which gives rise to higher symmetry crystal structures. PDF analysis was used to examine all likely candidate structures and to look for evidence of higher symmetry. The feasible phase space that evolves includes the ordered double perovskite structure Ba2(Ti, MV)O6 (M = Nb, Ta) Fm-3m, a disordered cubic structure, as a suitable high temperature analog, Ba(Ti, MV)O3Pm-3m, and an orthorhombic Ba(Ti, MV)O3Amm2, a room temperature structure that presents an unusually high level of lattice displacement, possibly due to octahedral tilting, and indication of a highly polarized crystal.

Chemistry↗
DOE OSTI2024

Is Ba 3 In 2 O 6 a high- T c superconductor?

It has been suggested that Ba 3 In 2 O 6 might be a high-Tc superconductor. Experimental investigation of the properties of Ba 3 In 2 O 6 was long inhibited by its instability in air. Recently epitaxial Ba 3 In 2 O 6 with a protective capping layer was demonstrated, which finally allows its electronic characterization. The optical bandgap of Ba3In2O6 is determined to be 2.99 eV in-the (001) plane and 2.83 eV along the c-axis direction by spectroscopic ellipsometry. First-principles calculations were carried out, yielding a result in good agreement with the experimental value. Various dopants were explored to induce (super-)conductivity in this otherwise insulating material. Neither A- nor B-site doping proved successful. The underlying reason is predominately the formation of oxygen interstitials as revealed by scanning transmission electron microscopy and first-principles calculations. Additional efforts to induce superconductivity were investigated, including surface alkali doping, optical pumping, and hydrogen reduction. To probe liquid-ion gating, Ba 3 In 2 O 6 was successfully grown epitaxially on an epitaxial SrRuO 3 bottom electrode. So far none of these efforts induced superconductivity in Ba 3 In 2 O 6 , leaving the answer to the initial question of whether Ba 3 In 2 O 6 is a high-T c superconductor to be 'no' thus far.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗