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All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

The distinct conditions of atmospheric and underground nuclear tests revealed by Zn isotopic compositions of nuclear debris samples

We analyzed the Zn isotopic compositions of nuclear debris samples from atmospheric and underground nuclear tests. Samples from the site of atmospheric tests exhibit a range of Zn isotopic fractionation (δ 66 Zn JMC-Lyon = 0.23–0.86 ‰) while samples from underground tests exhibit Zn isotopic compositions with minimal variation among samples and from terrestrial igneous rock standards (δ 66 ZnJMC-Lyon = 0.28–0.39 ‰). In conclusion, the larger range of δ 66 Zn JMC-Lyon observed in atmospheric test samples relative to underground test samples is likely the result of the open system characteristics of atmospheric nuclear tests and the closed system characteristics of underground nuclear tests.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2021

The subsurface structure of abraded Al–Zn–Mg–Cu alloy

Surface abrasion has been shown to introduce heavy shear stress and produce a few hundred nanometers thick altered surface layer (ASL) on Al alloys. Such ASLs exhibit microstructural changes at room temperature and different corrosion resistance than the underlying substrate. Here, we report how sample dimensions and temperature affect the deformed subsurface microstructure evolution on an abraded Al–Zn–Mg–Cu alloy using transmission electron microscopy (TEM) and atom probe tomography. The ASL microstructure evolves differently in the bulk sample than in the thin TEM specimen. In the freshly abraded ASL, the original η'/η precipitates and grain boundaries were deformed toward the abrasion direction. After 7-day natural aging of the freshly abraded bulk sample, well-defined subgrains formed locally in the ASL, and unusual Al 2 Cu (θ) and Mg x Zn y phases precipitated at the subgrain boundaries. However, during natural aging of this TEM specimen taken from the abraded and aged bulk samples, much faster changes occurred, including the continued formation of subgrains and θ particles in the entire ASL, and the diffusion of Zn atoms out of Mg x Zn y particles to form a Zn particle. On the other hand, no obvious microstructural changes occurred in the ASL during 3-month natural aging of the TEM specimen immediately taken from the freshly abraded sample. Finally, this work advances the understanding of how Al alloy microstructures respond during and following any shear deformation, and complex and unexpected effects of sample dimensions on the behavior.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Precision measurement of 65 Zn electron-capture decays with the KDK coincidence setup

65 Zn is a common calibration source, moreover used as a radioactive tracer in medical and biological studies. In many cases, γ-spectroscopy is a preferred method of 65 Zn standardization, which relies directly on the branching ratio of Jπ( 65 Zn) = 5/2- → Jπ( 65 Cu) = 5/2 - via electron capture (EC*). We measure the relative intensity of this branch to that proceeding directly to the ground state (EC 0 ) using a novel coincidence technique, finding I EC 0/IEC* = 0.9684 ± 0.0018. Re-evaluating the decay scheme of 65 Zn by adopting the commonly evaluated branching ratio of I β+ = 1.4271(7)% we obtain IEC* = (50.08 ± 0.06)%, and I EC 0 = (48.50 ± 0.06)%. The associated 1115 keV gamma intensity agrees with the previously reported NNDC value, and is now accessible with a factor of ~2 increase in precision. Our re-evaluation removes reliance on the deduction of this gamma intensity from numerous measurements, some of which disagree and depend directly on total activity determination. The KDK experimental technique provides a new avenue for verification or updates to the decay scheme of 65 Zn, and is applicable to other isotopes.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2023

Tuning the Radius Ratio to Enhance Thermoelectric Properties in the Zintl Compounds AM 2 Sb 2 (A = Ba, Sr; M = Zn, Cd)

Five novel Zintl phase solid solutions in the Ba 1–x Sr x Zn 2–y Cd y Sb 2 (0 ≤ x ≤ 0.13(1); 0 ≤ y ≤ 0.32(2)) system were successfully synthesized by the molten Pb metal-flux method, and the powder X-ray diffraction and single-crystal X-ray diffraction analyses proved that all five title compounds adopted the BaCu 2 S 2 -type phase having the orthorhombic Pnma space group (Z = 4, Pearson code oP20) with five crystallographically independent atomic sites. The previously studied BaCu 2 S 2 -type antimonides demonstrated a limited tolerance for doping in contrast to the CaAl 2 Si 2 -type antimonides. To understand the relatively narrower phase width and limited dopability of the title BaCu 2 S 2 -type phase than the CaAl 2 Si 2 -type phase in the overall Ba 1–x Sr x Zn 2–y Cd y Sb 2 system, the radius ratio of cations and anionic elements r + /r – for two structure types were thoroughly investigated. For the first time, the r + /r – ratio was identified as a critical factor for the phase selectivity: (1) r + /r – > 1 favored the BaCu 2 S 2 -type phase, and (2) r + /r – < 1 favored the CaAl 2 Si 2 -type phase. Further, we also revealed the structural transformation mechanism from the more widely observed CaAl 2 Si 2 -type phase to the title BaCu 2 S 2 -type phase as the relatively larger cationic elements were introduced to the system. A series of DFT calculations using the three hypothetical models indicated that a resonance peak near EF in the density of states curves was descended from the relatively flat band structure at several special symmetry points rationalizing the enhanced Seebeck coefficients of Ba 0.94(1) Sr 0.06 Zn 1.86(3) Cd 0.14 Sb 2 and Ba 0.96(1) Sr 0.04 Zn 1.68(2) Cd 0.32 Sb 2 . Electron localization function analysis rationalized the correlation between the polarity change of anionic Zn/Cd–Sb bonds and the charge carrier mobility on the anionic frameworks. Temperature-dependent thermoelectric properties were studied for the four title compounds, and the results proved that the Sr and Cd doping in the title Ba 1–x Sr x Zn 2–y Cd y Sb 2 system successfully enhanced the ZT values through the increased Seebeck coefficients and the reduced total thermal conductivities.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Semiconducting Zn x Mo 3 S 13 -GO Chalcocarbogel: A High-Capacity and Stable Sulfur-Equivalent Conversion-Based Electrode for Lithium-Ion Batteries

Lithium–sulfur batteries with a sulfur electrode offer a theoretical capacity of ∼1672 mAh g –1 , but rapid capacity loss mainly constrains their practical application. This work introduces a semiconducting and amorphous Zn x Mo 3 S 13 -GO (x = 0.5) chalcocarbogel sulfur-equivalent electrode with superior capacity and stability for lithium-ion batteries (LIBs). The Zn x Mo 3 S 13 -GO is synthesized in solution under ambient conditions, and its local structure contains S–S, M-Q (M = Mo, Zn; Q = S, O), C–S, and Mo–Mo bonding motifs with Mo coordination environment closely related to Mo 3 S 13 anions, as determined by X-ray photoelectron spectroscopy, synchrotron X-ray scattering, X-ray absorption spectroscopy, and ab initio molecular dynamics simulations. The Li/Zn x Mo 3 S 13 -GO cell offers an initial discharge capacity of 1019 mAh g –1 at a rate of C/3. After the activation cycles, the Li/Zn x Mo 3 S 13 -GO cell demonstrates good cycling stability, retaining a discharge capacity of 519.4 mAh g –1 after 250 cycles with ∼99.98% Coulombic efficiency and excellent rate capabilities. Moreover, it provides an initial discharge capacity of ∼574 mAh g –1 and maintains a retention capacity of 279 mAh g –1 at 1C after 625 cycles. The Lewis acidic Zn 2+ ion enhances the Lewis basic polysulfide anchoring ability and reduces the dissolution of polysulfides produced during the redox process through Zn–S covalent interaction, while the semiconducting and amorphous structure of the chalcocarbogel increases the electrical and ionic conductivity. Furthermore, this work highlights chalcocarbogels’ potential for developing high-capacity and stable electrodes for LIBs.

25 ENERGY STORAGE↗
DOE OSTI2025

Determination of Site Occupancy in the M–Pd–Zn (M = Cu, Ag, and Au) γ-Brass Phase by CALculation of PHAse Diagrams Modeling and Rietveld Refinement

The Pd–Zn γ-brass phase provides exciting opportunities for synthesizing site-isolated catalysts with precisely controlled Pd active site ensembles. Introducing a third metallic element into the γ-brass lattice further perturbs the catalytic active site ensembles. Here, in this work, we introduce coinage metallic elements M (M = Cu, Ag, and Au) into the Pd–Zn γ-brass phase and investigate the site occupation factors of each element in the γ-brass lattice. The CALculation of PHAse Diagrams (CALPHAD) modeling approach supported by energetics predicted by the density functional theory and X-ray and neutron diffraction with Rietveld refinement were used to identify the SOF on each Wyckoff site for various M amounts alloyed into the Pd–Zn γ-brass phase. The present analysis unveils the strong preference for Pd occupying the outer tetrahedral (OT) site in the γ-brass lattice, while the coinage metallic elements tend to substitute for Zn on the octahedral (OH) site. The determination of site occupancy in the bulk M–Pd–Zn γ-brass phase provides opportunities to investigate and tailor potential catalytically active site ensembles in the γ-brass phase materials.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Sputtered p-Type Cu x Zn 1– x S Back Contact to CdTe Solar Cells

As thin-film cadmium telluride (CdTe) solar cells gain prominence, one particular challenge is optimizing contacts and their interfaces to transfer charge without losses in efficiency. Back contact recombination is still significant and will prevent CdTe solar technology from reaching its full potential in device efficiency, and transparent back contacts have not been developed for bifacial solar technology or multijunction solar cells. To address these challenges, here we investigate sputtered Cu x Zn 1– x S as a p-type semi-transparent back contact material to thin-film polycrystalline CdTe solar cells at Cu concentrations x = 0.30, 0.45, and 0.60. This material is selected for its high hole conductivity (160–2120 S cm –1 ), wide optical band gap (2.25–2.75 eV), and variable ionization potential (approximately 6–7 eV) that can be aligned to that of CdTe. We report that without device optimization, CdTe solar cells with these Cu x Zn 1– x S back contacts perform as well as control cells with standard ZnTe:Cu back contacts. We observe no reduction in external quantum efficiency, low contact barrier heights of approximately 0.3 eV, and carrier lifetimes on par with those of baseline CdTe. These cells are relatively stable over one year in air, with V OC and efficiency of the x = 0.30 cell decreasing by only 1 and 3%, respectively. Using scanning electron microscopy and scanning transmission electron microscopy to investigate the Cu x Zn 1– x S/CdTe interface, we demonstrate that the Cu x Zn 1– x S layer segregates into a bilayer of Cu-Te-S and Zn-Cd-S, and thermodynamic reaction calculations support these findings. Despite its bilayer formation, the back contact still functions well. This investigation explains some of the physical mechanisms governing the device stack, inspires future work to understand interfacial chemistry and charge transfer, and elicits optimization to achieve higher-efficiency CdTe cells.

14 SOLAR ENERGY↗
DOE OSTI2020

Potentiodynamics of the Zinc and Proton Storage in Disordered Sodium Vanadate for Aqueous Zn-Ion Batteries

A rechargeable Zn-ion battery is a promising aqueous system, where coinsertion of Zn 2+ and H + could address the obstacles of the sluggish ionic transport in cathode materials imposed by multivalent battery chemistry. However, there is a lack of fundamental understanding of this dual-ion transport, especially the potentiodynamics of the storage process. Here, a quantitative analysis of Zn 2+ and H + transport in a disordered sodium vanadate (NaV 3 O 8 ) cathode material has been reported. Collectively, synchrotron X-ray analysis shows that both Zn 2+ and H + storages follow an intercalation storage mechanism in NaV 3 O 8 and proceed in a sequential manner, where intercalations of 0.26 Zn 2+ followed by 0.24 H + per vanadium atom occur during discharging, while reverse dynamics happens during charging. We find that such a unique and synergistic dual-ion sequential storage favors a high capacity (265 mA h g –1 ) and an energy density (221 W h kg –1 ) based on the NaV 3 O 8 cathode and a great cycling life (a capacity retention of 78% after 2000 cycles) in Zn/NaV 3 O 8 full cells.

36 MATERIALS SCIENCE↗
DOE OSTI2024

A Comparison of CdS and Zn(O,S) Buffer Layers in (Ag,Cu)(In,Ga)Se2 Solar Cells

Cu(In,Ga)Se 2 -based solar cells typically use a C dS buffer layer, even though its relatively low bandgap causes parasitic absorption. While alternatives to CdS have been explored in other studies, limited results have been shown for Ag-alloyed CIGS (ACIGS). In this study, ACIGS solar cells with both CdS and Zn(O,S) buffer layers were fabricated and compared for solar cell performance. The Zn(O,S) buffer slightly improved J sc through reduced absorption, although surface optimization is necessary. The Zn(O,S) ACIGS also had improved FF through reduced series resistance and ideality factor, which could be improved further through optimization. However, the Voc in the Zn(O,S) samples was reduced, likely due to increased bulk and front interface recombination. This study shows the promise of Zn(O,S) as a buffer layer in ACIGS solar cells and suggests pathways for further improvement.

absorption↗
NASA NTRS1991

Effect of Zn additions on precipitation during aging of alloy 8090

Precipitation events have been observed by TEM under two different aging conditions in three 'stretched' alloys, whose compositions are encompassed by the 8090 composition window but contain Zn additions of up to 1.07 wt pct. DSC was also used to obtain deeper insight of the precipitation-event effects obtainable through Zn content variation; it was thereby revealed that Zn is incorporated into the delta-prime phase, perhaps stabilizing it. Coarse, Zn-containing precipitates can form on the boundaries and within the interiors of the grains, when the Zn content reaches the presently investigated maximum of 1.07 wt pct.

Kilmer, R. J.↗
NASA NTRS2022

The Zn, S, and Cl Isotope Compositions of Mare Basalts: Implications for the Effects of Eruption Style and Pressure on Volatile Element Stable Isotope Fractionation on the Moon

We compare the stable isotope compositions of Zn, S, and Cl for Apollo mare basalts to better constrain the sources and timescales of lunar volatile loss. Mare basalts have broadly elevated yet limited ranges in δ(66)Zn, δ(34)S, and δ(37)Cl_(SBC+WSC) values of 1.27 ± 0.71, 0.55 ± 0.18, and 4.1 ± 4.0‰, respectively, compared to the silicate Earth at 0.15, –1.28, and 0‰, respectively. We find that the Zn, S, and Cl isotope compositions are similar between the low- and high-Ti mare basalts, providing evidence of a geochemical signature in the mare basalt source region that is inherited from lunar formation and magma ocean crystallization. The uniformity of these compositions implies mixing following mantle overturn, as well as minimal changes associated with subsequent mare magmatism. Degassing of mare magmas and lavas did not contribute to the large variations in Zn, S, and Cl isotope compositions found in some lunar materials (i.e., 15‰ in δ(66)Zn, 60‰ in δ(34)S, and 30‰ in δ(37)Cl). This reflects magma sources that experienced minimal volatile loss due to high confining pressures that generally exceeded their equilibrium saturation pressures. Alternatively, these data indicate effective isotopic fractionation factors were near unity. Our observations of S isotope compositions in mare basalts contrast to those for picritic glasses (Saal and Hauri 2021), which vary widely in S isotope compositions from –14.0 to 1.3‰, explained by extensive degassing of picritic magmas under high-P/P_(Sat) values (>0.9) during pyroclastic eruptions. The difference in the isotope compositions of picritic glass beads and mare basalts may result from differences in effusive (mare) and explosive (picritic) eruption styles, wherein the high-gas contents necessary for magma fragmentation would result in large effective isotopic fractionation factors during degassing of picritic magmas. Additionally, in highly vesiculated basalts, the δ(34)S and δ(37)Cl values of apatite grains are higher and more variable than the corresponding bulk-rock values. The large isotopic range in the vesiculated samples is explained by late-stage low-pressure “vacuum” degassing (P/P-(Sat) ~ 0) of mare lavas wherein vesicle formation and apatite crystallization took place post-eruption. Bulk-rock mare basalts were seemingly unaffected by vacuum degassing. Degassing of mare lavas only became important in the final stages of crystallization recorded in apatite—potentially facilitated by cracks/fractures in the crystallizing flow. We conclude that samples with wide-ranging volatile element isotope compositions are likely explained by localized processes, which do not represent the bulk Moon.

Halogens↗
DOE OSTI2020

Materials Data on Zn(BIr)2 by Materials Project

Zn(IrB)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ir is bonded in a 8-coordinate geometry to four equivalent Zn and four equivalent B atoms. All Ir–Zn bond lengths are 2.67 Å. All Ir–B bond lengths are 2.16 Å. Zn is bonded in a body-centered cubic geometry to eight equivalent Ir atoms. B is bonded in a 8-coordinate geometry to four equivalent Ir and four equivalent B atoms. All B–B bond lengths are 2.12 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Zn(CN)2 by Materials Project

Zn(CN)2 is Tungsten structured and crystallizes in the cubic P-43m space group. The structure is zero-dimensional and consists of one Zn(CN)4 cluster and one zinc molecule. In the Zn(CN)4 cluster, Zn2+ is bonded in a tetrahedral geometry to four equivalent N3- atoms. All Zn–N bond lengths are 1.97 Å. C2+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.17 Å. N3- is bonded in a linear geometry to one Zn2+ and one C2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Zn(GaNi)3 by Materials Project

Zn(NiGa)3 crystallizes in the cubic Ia-3d space group. The structure is three-dimensional. Ni is bonded in a distorted body-centered cubic geometry to two equivalent Zn and six equivalent Ga atoms. Both Ni–Zn bond lengths are 2.48 Å. There are a spread of Ni–Ga bond distances ranging from 2.45–2.57 Å. Zn is bonded to six equivalent Ni atoms to form distorted corner-sharing ZnNi6 cuboctahedra. Ga is bonded in a 6-coordinate geometry to six equivalent Ni atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Zn(Bi19O30)2 by Materials Project

Bi38ZnO60 crystallizes in the trigonal P3 space group. The structure is three-dimensional. Zn is bonded to four O atoms to form ZnO4 tetrahedra that share corners with twelve BiO5 square pyramids. There are three shorter (2.03 Å) and one longer (2.05 Å) Zn–O bond lengths. There are fourteen inequivalent Bi sites. In the first Bi site, Bi is bonded to five O atoms to form distorted BiO5 square pyramids that share corners with eight BiO5 square pyramids, a cornercorner with one ZnO4 tetrahedra, and an edgeedge with one BiO5 square pyramid. There are a spread of Bi–O bond distances ranging from 2.10–2.67 Å. In the second Bi site, Bi is bonded to five O atoms to form distorted BiO5 square pyramids that share corners with eight BiO5 square pyramids, a cornercorner with one BiO4 tetrahedra, and an edgeedge with one BiO5 square pyramid. There are a spread of Bi–O bond distances ranging from 2.11–2.65 Å. In the third Bi site, Bi is bonded to five O atoms to form distorted BiO5 square pyramids that share corners with eight BiO5 square pyramids, a cornercorner with one ZnO4 tetrahedra, and an edgeedge with one BiO5 square pyramid. There are a spread of Bi–O bond distances ranging from 2.12–2.69 Å. In the fourth Bi site, Bi is bonded to five O atoms to form distorted BiO5 square pyramids that share corners with eight BiO5 square pyramids, a cornercorner with one BiO4 tetrahedra, and an edgeedge with one BiO5 square pyramid. There are a spread of Bi–O bond distances ranging from 2.10–2.72 Å. In the fifth Bi site, Bi is bonded to five O atoms to form distorted BiO5 square pyramids that share corners with eight BiO5 square pyramids, a cornercorner with one BiO4 tetrahedra, and an edgeedge with one BiO5 square pyramid. There are a spread of Bi–O bond distances ranging from 2.12–2.70 Å. In the sixth Bi site, Bi is bonded to five O atoms to form distorted BiO5 square pyramids that share corners with eight BiO5 square pyramids, a cornercorner with one ZnO4 tetrahedra, and an edgeedge with one BiO5 square pyramid. There are a spread of Bi–O bond distances ranging from 2.11–2.67 Å. In the seventh Bi site, Bi is bonded to four O atoms to form corner-sharing BiO4 tetrahedra. There are one shorter (2.04 Å) and three longer (2.05 Å) Bi–O bond lengths. In the eighth Bi site, Bi is bonded to five O atoms to form distorted BiO5 square pyramids that share corners with eight BiO5 square pyramids, a cornercorner with one ZnO4 tetrahedra, and an edgeedge with one BiO5 square pyramid. There are a spread of Bi–O bond distances ranging from 2.11–2.69 Å. In the ninth Bi site, Bi is bonded to five O atoms to form distorted BiO5 square pyramids that share corners with eight BiO5 square pyramids, a cornercorner with one BiO4 tetrahedra, and an edgeedge with one BiO5 square pyramid. There are a spread of Bi–O bond distances ranging from 2.12–2.72 Å. In the tenth Bi site, Bi is bonded to five O atoms to form distorted BiO5 square pyramids that share corners with eight BiO5 square pyramids, a cornercorner with one BiO4 tetrahedra, and an edgeedge with one BiO5 square pyramid. There are a spread of Bi–O bond distances ranging from 2.10–2.66 Å. In the eleventh Bi site, Bi is bonded to five O atoms to form distorted BiO5 square pyramids that share corners with eight BiO5 square pyramids, a cornercorner with one BiO4 tetrahedra, and an edgeedge with one BiO5 square pyramid. There are a spread of Bi–O bond distances ranging from 2.12–2.71 Å. In the twelfth Bi site, Bi is bonded to five O atoms to form distorted BiO5 square pyramids that share corners with eight BiO5 square pyramids, a cornercorner with one BiO4 tetrahedra, and an edgeedge with one BiO5 square pyramid. There are a spread of Bi–O bond distances ranging from 2.11–2.64 Å. In the thirteenth Bi site, Bi is bonded to five O atoms to form distorted BiO5 square pyramids that share corners with eight BiO5 square pyramids, a cornercorner with one BiO4 tetrahedra, and an edgeedge with one BiO5 square pyramid. There are a spread of Bi–O bond distances ranging from 2.11–2.67 Å. In the fourteenth Bi site, Bi is bonded to four O atoms to form corner-sharing BiO4 tetrahedra. There are three shorter (2.04 Å) and one longer (2.05 Å) Bi–O bond lengths. There are twenty-four inequivalent O sites. In the first O site, O is bonded in a trigonal non-coplanar geometry to three Bi atoms. In the second O site, O is bonded in a trigonal planar geometry to three Bi atoms. In the third O site, O is bonded in a distorted trigonal non-coplanar geometry to three Bi atoms. In the fourth O site, O is bonded in a trigonal non-coplanar geometry to three Bi atoms. In the fifth O site, O is bonded in a trigonal planar geometry to three Bi atoms. In the sixth O site, O is bonded in a distorted trigonal non-coplanar geometry to three Bi atoms. In the seventh O site, O is bonded to four Bi atoms to form distorted corner-sharing OBi4 tetrahedra. In the eighth O site, O is bonded in a distorted trigonal non-coplanar geometry to three Bi atoms. In the ninth O site, O is bonded in a distorted trigonal non-coplanar geometry to three Bi atoms. In the tenth O site, O is bonded in a distorted trigonal non-coplanar geometry to three Bi atoms. In the eleventh O site, O is bonded in a distorted trigonal non-coplanar geometry to three Bi atoms. In the twelfth O site, O is bonded to one Zn and three Bi atoms to form corner-sharing OZnBi3 tetrahedra. In the thirteenth O site, O is bonded to four Bi atoms to form distorted corner-sharing OBi4 tetrahedra. In the fourteenth O site, O is bonded in a distorted trigonal non-coplanar geometry to three Bi atoms. In the fifteenth O site, O is bonded in a distorted trigonal non-coplanar geometry to three Bi atoms. In the sixteenth O site, O is bonded in a trigonal non-coplanar geometry to three Bi atoms. In the seventeenth O site, O is bonded in a distorted trigonal non-coplanar geometry to three Bi atoms. In the eighteenth O site, O is bonded in a trigonal planar geometry to three Bi atoms. In the nineteenth O site, O is bonded in a trigonal planar geometry to three equivalent Bi atoms. In the twentieth O site, O is bonded in a trigonal planar geometry to three equivalent Bi atoms. In the twenty-first O site, O is bonded to four Bi atoms to form distorted corner-sharing OBi4 tetrahedra. In the twenty-second O site, O is bonded to four Bi atoms to form corner-sharing OBi4 tetrahedra. In the twenty-third O site, O is bonded to one Zn and three equivalent Bi atoms to form corner-sharing OZnBi3 tetrahedra. In the twenty-fourth O site, O is bonded in a trigonal planar geometry to three equivalent Bi atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Zn(FeO2)4 by Materials Project

Zn(FeO2)4 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent Fe sites. In the first Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share edges with two equivalent ZnO6 octahedra and edges with six FeO6 octahedra. There is four shorter (1.95 Å) and two longer (1.97 Å) Fe–O bond length. In the second Fe site, Fe is bonded to six equivalent O atoms to form FeO6 octahedra that share corners with six equivalent ZnO6 octahedra and edges with six equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 12°. All Fe–O bond lengths are 2.06 Å. Zn is bonded to six equivalent O atoms to form ZnO6 octahedra that share corners with six equivalent FeO6 octahedra and edges with six equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 12°. All Zn–O bond lengths are 2.18 Å. There are two inequivalent O sites. In the first O site, O is bonded in a rectangular see-saw-like geometry to three Fe and one Zn atom. In the second O site, O is bonded in a distorted T-shaped geometry to three equivalent Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Zn(FeO2)2 by Materials Project

ZnFe2O4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eight inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three ZnO6 pentagonal pyramids, edges with six FeO6 octahedra, and an edgeedge with one ZnO6 pentagonal pyramid. There are a spread of Fe–O bond distances ranging from 1.93–2.04 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three ZnO6 pentagonal pyramids, edges with six FeO6 octahedra, and an edgeedge with one ZnO6 pentagonal pyramid. There are a spread of Fe–O bond distances ranging from 1.92–2.16 Å. In the third Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three ZnO6 pentagonal pyramids, edges with six FeO6 octahedra, and an edgeedge with one ZnO6 pentagonal pyramid. There are a spread of Fe–O bond distances ranging from 1.93–2.04 Å. In the fourth Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three ZnO6 pentagonal pyramids, edges with six FeO6 octahedra, and an edgeedge with one ZnO6 pentagonal pyramid. There are a spread of Fe–O bond distances ranging from 1.93–2.18 Å. In the fifth Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share edges with six FeO6 octahedra and edges with two ZnO6 pentagonal pyramids. There are a spread of Fe–O bond distances ranging from 1.93–2.00 Å. In the sixth Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share edges with six FeO6 octahedra and edges with two ZnO6 pentagonal pyramids. There are a spread of Fe–O bond distances ranging from 1.92–2.00 Å. In the seventh Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share edges with six FeO6 octahedra and edges with two ZnO6 pentagonal pyramids. There are a spread of Fe–O bond distances ranging from 1.92–2.00 Å. In the eighth Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share edges with six FeO6 octahedra and edges with two ZnO6 pentagonal pyramids. There are a spread of Fe–O bond distances ranging from 1.93–2.01 Å. There are four inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded to six O2- atoms to form distorted ZnO6 pentagonal pyramids that share corners with six FeO6 octahedra and edges with six FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–20°. There are a spread of Zn–O bond distances ranging from 2.09–2.28 Å. In the second Zn2+ site, Zn2+ is bonded to six O2- atoms to form distorted ZnO6 pentagonal pyramids that share corners with six FeO6 octahedra and edges with six FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–20°. There are a spread of Zn–O bond distances ranging from 2.09–2.27 Å. In the third Zn2+ site, Zn2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Zn–O bond distances ranging from 2.09–2.30 Å. In the fourth Zn2+ site, Zn2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Zn–O bond distances ranging from 2.08–2.30 Å. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Fe3+ and one Zn2+ atom. In the second O2- site, O2- is bonded to three Fe3+ and one Zn2+ atom to form distorted OZnFe3 trigonal pyramids that share corners with four OZn2Fe3 trigonal bipyramids, corners with five OZnFe3 trigonal pyramids, edges with four OZn2Fe3 trigonal bipyramids, and an edgeedge with one OZnFe3 trigonal pyramid. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Fe3+ and one Zn2+ atom. In the fourth O2- site, O2- is bonded to three Fe3+ and one Zn2+ atom to form distorted OZnFe3 trigonal pyramids that share corners with four OZn2Fe3 trigonal bipyramids, corners with five OZnFe3 trigonal pyramids, edges with four OZn2Fe3 trigonal bipyramids, and an edgeedge with one OZnFe3 trigonal pyramid. In the fifth O2- site, O2- is bonded to three Fe3+ and one Zn2+ atom to form OZnFe3 trigonal pyramids that share corners with four OZn2Fe3 trigonal bipyramids, corners with three OZnFe3 trigonal pyramids, and edges with four OZn2Fe3 trigonal bipyramids. In the sixth O2- site, O2- is bonded to three Fe3+ and one Zn2+ atom to form OZnFe3 trigonal pyramids that share corners with four OZn2Fe3 trigonal bipyramids, corners with six OZnFe3 trigonal pyramids, edges with four OZn2Fe3 trigonal bipyramids, and an edgeedge with one OZnFe3 trigonal pyramid. In the seventh O2- site, O2- is bonded to three Fe3+ and one Zn2+ atom to form OZnFe3 trigonal pyramids that share corners with four OZn2Fe3 trigonal bipyramids, corners with three OZnFe3 trigonal pyramids, and edges with four OZn2Fe3 trigonal bipyramids. In the eighth O2- site, O2- is bonded to three Fe3+ and one Zn2+ atom to form OZnFe3 trigonal pyramids that share corners with four OZn2Fe3 trigonal bipyramids, corners with six OZnFe3 trigonal pyramids, edges with four OZn2Fe3 trigonal bipyramids, and an edgeedge with one OZnFe3 trigonal pyramid. In the ninth O2- site, O2- is bonded to three Fe3+ and two Zn2+ atoms to form distorted OZn2Fe3 trigonal bipyramids that share corners with five OZn2Fe3 trigonal bipyramids, corners with three OZnFe3 trigonal pyramids, edges with four OZn2Fe3 trigonal bipyramids, and edges with two OZnFe3 trigonal pyramids. In the tenth O2- site, O2- is bonded to three Fe3+ and two Zn2+ atoms to form OZn2Fe3 trigonal bipyramids that share corners with five OZn2Fe3 trigonal bipyramids, corners with three OZnFe3 trigonal pyramids, edges with four OZn2Fe3 trigonal bipyramids, and edges with four OZnFe3 trigonal pyramids. In the eleventh O2- site, O2- is bonded to three Fe3+ and two Zn2+ atoms to form OZn2Fe3 trigonal bipyramids that share corners with five OZn2Fe3 trigonal bipyramids, corners with three OZnFe3 trigonal pyramids, edges with four OZn2Fe3 trigonal bipyramids, and edges with two OZnFe3 trigonal pyramids. In the twelfth O2- site, O2- is bonded to three Fe3+ and two Zn2+ atoms to form OZn2Fe3 trigonal bipyramids that share corners with five OZn2Fe3 trigonal bipyramids, corners with three OZnFe3 trigonal pyramids, edges with four OZn2Fe3 trigonal bipyramids, and edges with four OZnFe3 trigonal pyramids. In the thirteenth O2- site, O2- is bonded to three Fe3+ and two Zn2+ atoms to form distorted OZn2Fe3 trigonal bipyramids that share corners with five OZn2Fe3 trigonal bipyramids, corners with three OZnFe3 trigonal pyramids, edges with four OZn2Fe3 trigonal bipyramids, and edges with two OZnFe3 trigonal pyramids. In the fourteenth O2- site, O2- is bonded to three Fe3+ and two Zn2+ atoms to form OZn2Fe3 trigonal bipyramids that share corners with five OZn2Fe3 trigonal bipyramids, corners with three OZnFe3 trigonal pyramids, edges with four OZn2Fe3 trigonal bipyramids, and edges with four OZnFe3 trigonal pyramids. In the fifteenth O2- site, O2- is bonded to three Fe3+ and two Zn2+ atoms to form OZn2Fe3 trigonal bipyramids that share corners with five OZn2Fe3 trigonal bipyramids, corners with three OZnFe3 trigonal pyramids, edges with four OZn2Fe3 trigonal bipyramids, and edges with two OZnFe3 trigonal pyramids. In the sixteenth O2- site, O2- is bonded to three Fe3+ and two Zn2+ atoms to form OZn2Fe3 trigonal bipyramids that share corners with five OZn2Fe3 trigonal bipyramids, corners with three OZnFe3 trigonal pyramids, edges with four OZn2Fe3 trigonal bipyramids, and edges with four OZnFe3 trigonal pyramids.

36 MATERIALS SCIENCE↗