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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on KB(CO2)4 by Materials Project

KB(CO2)4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.82–3.21 Å. B3+ is bonded in a tetrahedral geometry to four O2- atoms. There is two shorter (1.48 Å) and two longer (1.49 Å) B–O bond length. There are two inequivalent C3+ sites. In the first C3+ site, C3+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.22 Å) and one longer (1.33 Å) C–O bond length. In the second C3+ site, C3+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.22 Å) and one longer (1.34 Å) C–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to one B3+ and one C3+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent K1+ and one C3+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and one C3+ atom. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to one K1+, one B3+, and one C3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KB(S2O7)2 by Materials Project

KB(S2O7)2 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.80–3.40 Å. In the second K1+ site, K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.84–3.21 Å. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded to four O2- atoms to form BO4 tetrahedra that share corners with four SO4 tetrahedra. There is two shorter (1.48 Å) and two longer (1.49 Å) B–O bond length. In the second B3+ site, B3+ is bonded to four O2- atoms to form BO4 tetrahedra that share corners with four SO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.47–1.49 Å. There are eight inequivalent S6+ sites. In the first S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share a cornercorner with one BO4 tetrahedra and a cornercorner with one SO4 tetrahedra. There are a spread of S–O bond distances ranging from 1.43–1.67 Å. In the second S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share a cornercorner with one BO4 tetrahedra and a cornercorner with one SO4 tetrahedra. There are a spread of S–O bond distances ranging from 1.42–1.65 Å. In the third S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share a cornercorner with one BO4 tetrahedra and a cornercorner with one SO4 tetrahedra. There are a spread of S–O bond distances ranging from 1.42–1.64 Å. In the fourth S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share a cornercorner with one BO4 tetrahedra and a cornercorner with one SO4 tetrahedra. There are a spread of S–O bond distances ranging from 1.43–1.65 Å. In the fifth S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share a cornercorner with one BO4 tetrahedra and a cornercorner with one SO4 tetrahedra. There are a spread of S–O bond distances ranging from 1.43–1.65 Å. In the sixth S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share a cornercorner with one BO4 tetrahedra and a cornercorner with one SO4 tetrahedra. There are a spread of S–O bond distances ranging from 1.42–1.67 Å. In the seventh S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share a cornercorner with one BO4 tetrahedra and a cornercorner with one SO4 tetrahedra. There are a spread of S–O bond distances ranging from 1.42–1.66 Å. In the eighth S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share a cornercorner with one BO4 tetrahedra and a cornercorner with one SO4 tetrahedra. There are a spread of S–O bond distances ranging from 1.43–1.66 Å. There are twenty-eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and one S6+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and one S6+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and one S6+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and one S6+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and one S6+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and one S6+ atom. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and one S6+ atom. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and one S6+ atom. In the ninth O2- site, O2- is bonded in a single-bond geometry to two K1+ and one S6+ atom. In the tenth O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and one S6+ atom. In the eleventh O2- site, O2- is bonded in a single-bond geometry to one S6+ atom. In the twelfth O2- site, O2- is bonded in a distorted single-bond geometry to two K1+ and one S6+ atom. In the thirteenth O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and one S6+ atom. In the fourteenth O2- site, O2- is bonded in a single-bond geometry to one K1+ and one S6+ atom. In the fifteenth O2- site, O2- is bonded in a single-bond geometry to one K1+ and one S6+ atom. In the sixteenth O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and one S6+ atom. In the seventeenth O2- site, O2- is bonded in a bent 120 degrees geometry to one B3+ and one S6+ atom. In the eighteenth O2- site, O2- is bonded in a bent 120 degrees geometry to one B3+ and one S6+ atom. In the nineteenth O2- site, O2- is bonded in a bent 120 degrees geometry to one B3+ and one S6+ atom. In the twentieth O2- site, O2- is bonded in a bent 120 degrees geometry to one B3+ and one S6+ atom. In the twenty-first O2- site, O2- is bonded in a bent 120 degrees geometry to one B3+ and one S6+ atom. In the twenty-second O2- site, O2- is bonded in a bent 120 degrees geometry to one B3+ and one S6+ atom. In the twenty-third O2- site, O2- is bonded in a bent 120 degrees geometry to one B3+ and one S6+ atom. In the twenty-fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one B3+ and one S6+ atom. In the twenty-fifth O2- site, O2- is bonded in a bent 120 degrees geometry to two S6+ atoms. In the twenty-sixth O2- site, O2- is bonded in a bent 120 degrees geometry to two S6+ atoms. In the twenty-seventh O2- site, O2- is bonded in a bent 120 degrees geometry to two S6+ atoms. In the twenty-eighth O2- site, O2- is bonded in a bent 120 degrees geometry to two S6+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KB(SO4)2 by Materials Project

KB(SO4)2 crystallizes in the tetragonal P4/ncc space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight equivalent O2- atoms. There are four shorter (2.87 Å) and four longer (2.95 Å) K–O bond lengths. B3+ is bonded to four equivalent O2- atoms to form BO4 tetrahedra that share corners with four equivalent SO4 tetrahedra. All B–O bond lengths are 1.48 Å. S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with two equivalent BO4 tetrahedra. There is two shorter (1.44 Å) and two longer (1.56 Å) S–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to one B3+ and one S6+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent K1+ and one S6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2022

The Arabidopsis T‐DNA mutant SALK_008491 carries a 14‐kb deletion on chromosome 3 that provides rare insights into the plant response to dynamic light stress

Abstract In nature, plants experience rapid changes in light intensity and quality throughout the day. To maximize growth, they have established molecular mechanisms to optimize photosynthetic output while protecting components of the light‐dependent reaction and CO 2 fixation pathways. Plant phenotyping of mutant collections has become a powerful tool to unveil the genetic loci involved in environmental acclimation. Here, we describe the phenotyping of the transfer‐DNA (T‐DNA) insertion mutant line SALK_008491, previously known as nhd1‐1 . Growth in a fluctuating light regime caused a loss in growth rate accompanied by a spike in photosystem (PS) II damage and increased non‐photochemical quenching (NPQ). Interestingly, an independent nhd1 null allele did not recapitulate the NPQ phenotype. Through bulk sequencing of a backcrossed segregating F 2 pool, we identified an ~14‐kb large deletion on chromosome 3 (Chr3) in SALK_008491 affecting five genes upstream of NHD1 . Besides NHD1 , which encodes for a putative plastid Na + /H + antiporter, the stromal NAD‐dependent D‐3‐phosphoglycerate dehydrogenase 3 ( PGDH3 ) locus was eradicated. Although some changes in the SALK_008491 mutant's photosynthesis can be assigned to the loss of PGDH3, our follow‐up studies employing respective single mutants and complementation with overlapping transformation‐competent artificial chromosome (TAC) vectors reveal that the exacerbated fluctuating light sensitivity in SALK_008491 mutants result from the simultaneous loss of PGDH3 and NHD1. Altogether, the data obtained from this large deletion‐carrying mutant provide new and unintuitive insights into the molecular mechanisms that function to protect the photosynthetic machinery. Moreover, our study renews calls for caution when setting up reverse genetic studies using T‐DNA lines. Although second‐site insertions, indels, and SNPs have been reported before, large deletion surrounding the insertion site causes yet another problem. Nevertheless, as shown through this research, such unpredictable genetic events following T‐DNA mutagenesis can provide unintuitive insights that allow for understanding complex phenomena such as the plant acclimation to dynamic high light stress.

Lopez, Laura S.↗
DOE OSTI2023

kb_DRAM: annotation and metabolic profiling of genomes with DRAM in KBase

Microbial genome annotation is the process of identifying structural and functional elements in DNA sequences and subsequently attaching biological information to those elements. DRAM is a tool developed to annotate bacterial, archaeal, and viral genomes derived from pure cultures or metagenomes. DRAM goes beyond traditional annotation tools by distilling multiple gene annotations to genome level summaries of functional potential. Despite these benefits, a downside of DRAM is the requirement of large computational resources, which limits its accessibility. Further, it did not integrate with downstream metabolic modeling tools that require genome annotation. To alleviate these constraints, DRAM and the viral counterpart, DRAM-v, are now available and integrated with the freely accessible KBase cyberinfrastructure. With kb_DRAM users can generate DRAM annotations and functional summaries from microbial or viral genomes in a point-and-click interface, as well as generate genome-scale metabolic models from DRAM annotations.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Materials Data on KB(CN)4 by Materials Project

K(CN)4B crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional and consists of four boron molecules and one K(CN)4 framework. In the K(CN)4 framework, K1+ is bonded in a distorted body-centered cubic geometry to eight equivalent N3- atoms. There are four shorter (2.95 Å) and four longer (3.24 Å) K–N bond lengths. 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 1-coordinate geometry to two equivalent K1+ and one C2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KB by Materials Project

BK1 is Halite, Rock Salt structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. K is bonded to six equivalent B atoms to form a mixture of edge and corner-sharing KB6 octahedra. The corner-sharing octahedral tilt angles are 0°. All K–B bond lengths are 3.15 Å. B is bonded to six equivalent K atoms to form a mixture of edge and corner-sharing BK6 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KB(CF3)4 by Materials Project

K(CF3)4B crystallizes in the orthorhombic P2_12_12_1 space group. The structure is three-dimensional and consists of four boron molecules and one K(CF3)4 framework. In the K(CF3)4 framework, K1+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of K–F bond distances ranging from 2.65–3.22 Å. There are four inequivalent C2+ sites. In the first C2+ site, C2+ is bonded in a trigonal non-coplanar geometry to three F1- atoms. All C–F bond lengths are 1.38 Å. In the second C2+ site, C2+ is bonded in a trigonal non-coplanar geometry to three F1- atoms. There are a spread of C–F bond distances ranging from 1.37–1.39 Å. In the third C2+ site, C2+ is bonded in a trigonal non-coplanar geometry to three F1- atoms. There is one shorter (1.37 Å) and two longer (1.39 Å) C–F bond length. In the fourth C2+ site, C2+ is bonded in a trigonal non-coplanar geometry to three F1- atoms. All C–F bond lengths are 1.38 Å. There are twelve inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted single-bond geometry to one K1+ and one C2+ atom. In the second F1- site, F1- is bonded in a distorted single-bond geometry to one K1+ and one C2+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to one K1+ and one C2+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one K1+ and one C2+ atom. In the fifth F1- site, F1- is bonded in a single-bond geometry to one K1+ and one C2+ atom. In the sixth F1- site, F1- is bonded in a single-bond geometry to one C2+ atom. In the seventh F1- site, F1- is bonded in a distorted single-bond geometry to one K1+ and one C2+ atom. In the eighth F1- site, F1- is bonded in a single-bond geometry to one K1+ and one C2+ atom. In the ninth F1- site, F1- is bonded in a single-bond geometry to one K1+ and one C2+ atom. In the tenth F1- site, F1- is bonded in a single-bond geometry to one K1+ and one C2+ atom. In the eleventh F1- site, F1- is bonded in a single-bond geometry to one C2+ atom. In the twelfth F1- site, F1- is bonded in a single-bond geometry to one K1+ and one C2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2022

KBase Narrative - kb_DRAM E. coli annotation

Here we are annotating a E. coli K-12 genome using both DRAM and RAST then using those annotations to build models. The genome is from NCBI RefSeq ID NC_000913.

Shaffer, Michael↗
DOE OSTI2023

Saccharomycopsis sp. KB-2023a isolate UFMG-CM-Y6991, whole genome shotgun sequencing project

Three yeast isolates were obtained from soil and rotting wood samples collected in an Amazonian rainforest biome in Brazil. Comparison of the intergenic spacer 5.8S region and the D1/D2 domains of the large subunit rRNA gene showed that the isolates represent a novel species of the genus Saccharomycopsis. A tree inferred from the D1/D2 sequences placed the novel species near a subclade containing Saccharomycopsis lassenensis, Saccharomycopsis fermentans, Saccharomycopsis javanensis, Saccharomycopsis babjevae, Saccharomycopsis schoenii and Saccharomycopsis oosterbeekiorum, but with low bootstrap support. In terms of sequence divergence, the novel species had the highest identity in the D1/D2 domains with Saccharomycopsis capsularis, from which it differed by 36 substitutions. In contrast, a phylogenomic analysis based on 1061 single-copy orthologs for a smaller set of Saccharomycopsis species whose whole genome sequences are available indicated that the novel species represented by strain UFMG-CM-Y6991 is phylogenetically closer to Saccharomycopsis fodiens and Saccharomycopsis sp. TF2021a (=Saccharomycopsis phalluae). The novel yeast is homothallic and produces asci with one spheroidal ascospore with an equatorial or subequatorial ledge. The name Saccharomycopsis praedatoria sp. nov. is proposed to accommodate the novel species. The holotype of Saccharomycopsis praedatoria is CBS 16589(T). The MycoBank number is MB849369. S. praedatoria was able to kill cells of Saccharomyces cerevisiae by means of penetration with infection pegs, a trait common to most species of Saccharomycopsis.

Amazonian Forest↗
DOE OSTI2022

Kink mechanism in Cu/Nb nanolaminates explored by $\mathcal{in}$ $\mathcal{situ}$ pillar compression

We report Nano metallic laminates (NMLs) exhibit different failure modes depending on the loading conditions due to their mechanical anisotropies. Kinking is a typical failure mode in many NMLs compressed along a layer-parallel direction. However, a detailed description of the microstructure evolution during kink band (KB) formation and an in-depth understanding of the formation mechanisms are lacking. In this work, the KB process is investigated in Cu/Nb NMLs by in situ micro pillar compression in the scanning electron microscope (SEM) along a layer-parallel direction. Post-mortem S/TEM and transmission Kikuchi diffraction (TKD) analyses show that kink banding leads to significant microstructure changes characterized by an accumulation of geometrically necessary dislocations (GNDs) and of tilt geometrically necessary boundaries (GNBs) near KB boundaries (KBBs). The distinct microstructure evolution implies that KB formation is facilitated by the inhomogeneous microstructures resulting in constrained deformation modes. Specifically, dislocations active on slip planes nearly parallel to the interfaces make a major contribution to kink evolution after the onset of kinking. Once layer-parallel slip systems are activated, preexisting lattice dislocations and dislocations nucleating from interfaces will accumulate as GNDs near KBBs via the stochastic storage of lattice dislocations that have certain Burgers vectors. GNDs can further transform into GNBs via cross-slip and climb driven processes near the KBB. Furthermore, GNBs near KBBs can grow by incorporating more GNDs or by coalescence to accommodate the KB evolution. We further hypothesize that microstructural perturbations and their ensuing stresses can initiate KB formation in Cu/Nb NMLs.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Proton Quenching in Rare-Earth Inorganic Scintillators: GAGG:Ce and YSO:Ce

Scintillator detectors are an integral component of radiation detection systems for a variety of applications such as medical imaging, accelerator diagnostics, and space science. Typically, a scintillator detector’s response is characterized using gamma sources to understand the detection response to different types of radiation, including charged particle detection. However, there exists a nonlinearity of the amount of light produced from an incident gamma ray of specific energy and the light produced from an incident charged particle of the same energy. This important effect, known as quenching, must be accounted for to interpret energies from charged particles incident on detectors. In this article, we present results of quenching parameterization for two types of cerium-doped inorganic scintillators, Y2SiO5:Ce (YSO:Ce) and Gd3Al2Ga3O12:Ce (GAGG:Ce). We measured the light output from incident proton energies from 1 to 25 MeV using a 3-MV tandem accelerator and two reactions: Au(p,p)Au and 3He(d,p)⁴He. Using gamma-ray sources to calibrate the detectors, we compared the measured electron-equivalent energy versus the incident energy expected. Using an adaptation of the Birks semi-empirical formula, we extracted the Birks parameter (kB) to understand quenching. For one of the GAGG:Ce samples, the kB parameter of 0.0072 [g cm-2 MeV-1] is comparable to a similar study where the value of kB was 0.0065 [g cm-2 MeV-1]. For YSO:Ce, no other kB values were found in the literature. Three different types of GAGG:Ce were used to collect measurements of kB as a function of dopant concentration.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2023

Ion Beam Figuring System for Synchrotron X-Ray Mirrors Achieving Sub-0.2-µrad and Sub-0.5-nm Root Mean Square

Abstract Optics with high-precision height and slope are increasingly desired in numerous industrial fields. For instance, Kirkpatrick–Baez (KB) mirrors play an important role in synchrotron X-ray applications. A KB system is composed of two aspherical, grazing-incidence mirrors used to focus an X-ray beam. The fabrication of KB mirrors is challenging due to the aspherical departure of the mirror surfaces from base geometries and the high-quality requirements for slope and height residuals. In this paper, we present the process of manufacturing an elliptical cylinder KB mirror using our in-house-developed ion beam figuring (IBF) and metrology technologies. First, the key aspects of figuring and finishing processes with IBF are illustrated in detail. The effect of positioning error on the convergence of the residual slope error is highlighted and compensated. Finally, inspection and cross-validation using different metrology instruments are performed and used as the final validation of the mirror. Results confirm that relative to the requested off-axis ellipse, the mirror has achieved 0.15-µrad root mean square (RMS) and 0.36-nm RMS residual slope and height errors, respectively, while maintaining the initial 0.3-nm RMS microroughness.

36 MATERIALS SCIENCE↗
DOE OSTI2020

An intra-node HPC network architecture with nanosecond-scale photonic switches

We propose a single-stage network architecture for intra-node connectivity that makes use of nanosecond-scale photonic switches. Although buffering at the switch points is of vital importance for complex multi-stage networks, this is not the case for smaller-scale single-stage networks where the end nodes are located only one hop apart. By limiting the buffering to the end points, the proposed architecture manages to minimize the required electro-optic and opto-electronic conversions, leading in this way to both low end-to-end latency and better energy efficiency. Combining these advantages with nanosecond-scale switching times can allow for high-throughput operation even for frequent switch reconfigurations. The performance of the proposed architecture is evaluated via discrete-event simulations for a wide range of synthetic-traffic cases. The simulation results show that high-throughput operation of ≥90% can be achieved even for small message sizes, i.e., 32 KB for all-to-all communication and 2 KB for uniform random traffic, at a data rate of 400 Gb/s and a switch reconfiguration time of ≤72 ns. Moreover, if 100-ns reconfiguration times are achievable as opposed to 150-ns, then for the all-to-all traffic case a 16% and 28% reduction in completion time can be achieved for message sizes of 8 KB and 1 KB, respectively. In a forthcoming era of optically interfaced processors and accelerators, nanosecond-scale photonic switches appear as a highly promising solution for keeping up with the intra-node bandwidth scaling due to their high-bandwidth, low-latency and fast-switching capabilities.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2024

Superconductivity in CH 4 and BH – 4 containing compounds derived from the high-pressure superhydrides

Inspired by the synthesis of the high-pressure Fm3m LaH 10 superconducting superhydride, systematic density functional theory (DFT) calculations are performed to study ternaries that could be derived from it by replacing two of the hydrogen atoms with boron or carbon and varying the identity of the electropositive element. Though many of the resulting alkali-metal and alkaline-earth MC 2 H 8 phases are predicted to be dynamically stable at mild pressures, their superconducting critical temperatures (T c s) are low because their metallicity results from the filling of an electride-like band. Substitution with a trivalent element leads to phases with substantial metal d- character at the Fermi level whose T c s are typically above 40 K. Here, among the MB 2 H 8 phases examined, KB 2 H 8 , RbB 2 H 8 and CsB 2 H 8 are predicted to be dynamically stable at very mild pressures, and their stability is rationalized by a DFT-Chemical Pressure analysis that elucidates the role of the M atom size. Quantum anharmonic effects strongly affect the properties of KB 2 H 8 , the highest predicted T c compound, near 10 GPa, but molecular dynamics simulations reveal it would decompose below its T c at this pressure. Nonetheless, at ca. 50 GPa KB 2 H 8 is predicted to be thermally stable with a superconducting figure of merit surpassing that of the recently synthesized LaBeH 8 .

36 MATERIALS SCIENCE↗
DOE OSTI2023

The effect of annealing on kink band formation in Ag/Fe nanolaminates

Kink banding is a common, though not well understood, failure mechanism in anisotropic materials such as nano metallic laminates (NMLs). In this work, we investigate the effect of annealing on kink band (KB) formation in Ag/Fe NMLs prepared by accumulative roll bonding (ARB) using in situ micropillar compression, scanning/transmission electron microscopy (S/TEM), and transmission Kikuchi diffraction (TKD) analyses. Our results show that annealing increases the KB initiation strain, decreases the probability of KB formation, and decreases the load drop magnitude accompanying kink banding in Ag/Fe NMLs. Post-compression analyses reveal that annealing facilitates more uniform deformation of pillars and affects the formation of geometrically necessary grain boundaries (GNBs) near the kink band boundary (KBB). Compared to its as-rolled counterpart, annealed Ag/Fe has wider KBs with blunter KBBs.

36 MATERIALS SCIENCE↗