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Learning and Controlling Silicon Dopant Transitions in Graphene Using Scanning Transmission Electron Microscopy
A machine learning approach is introduced to determine the transition dynamics of silicon atoms on a single layer of carbon atoms, when stimulated by the electron beam of a scanning transmission electron microscope (STEM). This method is data-centric, leveraging data collected on a STEM. The data samples are processed and filtered to produce symbolic representations, which is used to train a neural network to predict transition probabilities. These learned transition dynamics are then leveraged to guide a single silicon atom throughout the lattice to pre-determined target destinations. Empirical analyses are presented that demonstrate the efficacy and generality of the approach.
Boron Dopant Induced Electron-Rich Bismuth for Electrochemical CO[subscript 2] Reduction with High S
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Influence of Grain Boundary Character on Dopants Segregation in Nanocrystalline Aluminum
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Ab initio prediction of charged species distribution at grain boundaries: Effects of structure and dopants
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Atomically Dispersed Dopants for Stabilizing Ceria Surface Area
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Optimization of capsule dopant levels to improve fuel areal density*
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Correlating the effect of dopant type (Al, Ga, Ta) on the mechanical and electrical properties of hot-pressed Li-garnet electrolyte
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An evaluation of tri-valent oxide (Cr 2 O 3 ) as a grain enlarging dopant for UO 2 nuclear fuels fabricated under reducing environment
A study was performed to evaluate the microstructure and crystallography of nominally 500–2000 Cr 2 O 3 -doped UO 2 fabricated in a temperature range of 1150–1750°C under reducing experimental conditions. We observed an increase in grain size of the samples with the increase in heat treating temperature as expected. For a given sintering temperature (1700–1750°C), an increase in the grain size was also observed with the increase in Cr 2 O 3 concentration up to a value of ~1000–1200 wppm. A decrease in fission gas release as a function of grain size was estimated for the Cr 2 O 3 -doped UO 2 samples assuming specified post-irradiation annealing conditions. A nearly linear decrease was obtained in the lattice parameter of the Cr 2 O 3 -doped UO 2 fcc phase with the increase in Cr 2 O 3 concentration, especially up to a nominal value of 1000 wppm. The lattice parameter decrease was also persistent with the increase in the average grain size as a result of addition of Cr 2 O 3 into the UO 2 lattice. An increase in the crystallite size and a decrease in the microstrain of the $fcc$ phase were observed with the increase in the average grain size of the samples, indicating a higher crystallinity of the Cr 2 O 3 -doped samples than that of the undoped UO 2 sample.
Inhomogeneous Doping of Perovskite Materials by Dopants from Hole-Transport Layer
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Efficient computational search for lanthanide-binding additive dopants for advanced U-Zr based fuels
A rational design strategy combining theory and experiment is highly desirable for the development of U-Zr based fuels that are resistant to lanthanide-induced fuel-cladding chemical interaction (FCCI). Here, we performed rapid computational screening of FCCI-mitigating (via strong lanthanide-binding) elements across the periodic table by utilizing three simple criteria and density functional theory (DFT) calculated total energies of relevant elements and compounds retrieved from high-throughput DFT databases. In addition to successfully identifying previously demonstrated additives, our search leads to the discovery of Bi as a highly effective element among all 68 elements screened, and its effectiveness was experimentally confirmed in this study.
How silicon and boron dopants govern the cryogenic scintillation properties of N -type GaAs
This work is the first report describing how the concentrations of silicon and boron govern the cryogenic scintillation properties of n-type GaAs. It shows that valence band holes are promptly trapped on radiative centers and then combine radiatively with silicon donor band electrons at rates that increase with the density of free carriers. It also presents the range of silicon and boron concentrations needed for efficient light emission under X-ray excitation, which along with its low band gap and apparent absence of afterglow, make scintillating GaAs suitable for the detection of rare, low-energy electronic excitations from interacting dark matter particles. A total of 29 samples from four different suppliers were studied. Luminosities and timing responses were measured for the four principal emission bands centered at 860, 930, 1070, and 1335 nm, and for the total emissions. Excitation pulses of 40 kVp X-rays were provided by a light-excited X-ray tube driven by an ultra-fast laser. Scintillation emissions from 800 to 1350 nm were measured using an InGaAs photomultiplier. Within the concentration ranges of free carriers from 2 x 10 16 /cm 3 to 6 x 10 17 /cm 3 and boron from 1.5 × 10 18 /cm 3 to 6 x 10 18 /cm 3 , nine samples have luminosities > 70 photons/keV and two have luminosities > 110 photons/keV. Other samples in that range have lower luminosities due to higher concentrations of non-radiative centers. The decay times decrease by typically a factor of ten with increasing free carrier concentrations from 10 17 /cm 3 to 2 x 10 18 /cm 3 .
Role of zirconium in neodymium-dopants interactions within uranium-based metallic fuels
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Identifying Lanthanide Energy Levels in Semiconductor Nanoparticles Enables Tailored Multicolor Emission through Rational Dopant Combinations
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