Lotiskorea Newsletter Vol. 30
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📖 Do you want to know more about metallic thin films and growth dynamics? In this latest article, Katayun Barmak, Matthew Patrick and Jeffrey Rickman review the development of grain growth dynamics in nanocrystalline metallic films using the #FusionAX system including #AXON!
💡Grain growth is a phenomenon pivotal in material science and has long eluded comprehensive characterization due to its complex nature. On top of that, most models still fail to fully capture the behavior of true grain growth phenomena at the nanometer scale.
📓This review underscores crucial observations, from the universal grain size distribution to the intriguing correlations between grain boundary character distributions in thin film and bulk materials.
🤖 With automated grain boundary segmentation, low thermal mass microelectromechanical systems, and integrated hardware-software solutions for drift correction and data management (done by AXON), barriers to large-scale and in situ data acquisition were overcome. With these discoveries, next generation grain growth studies on thin films will become more accessible.
Want to read the review? Find it here!
https://hubs.li/Q02qM1j30 |
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📖 Have you ever wanted to look at quantum conductance effects? In these newest publication by Gianluca Milano , Federico Raffone, Katarzyna Bejtka, Ivan De Carlo Matteo Fretto, Fabrizio Candido Pirri, Giancarlo Cicero, Carlo Ricciardi and Ilia Valov memresitive nanowires were imaged using the #FusionAX system!
⚡🔬In this recent study, the authors look at relationships between electrochemical processes, ionic dynamics, and the formation of atomic-sized conductive filaments in memristive Ag nanowires (NWs) using in situ biasing measurements for STEM.
📈 By combining advanced classical molecular dynamics (MD) algorithms with quantum transport simulations (DFT), they were able to gain insights into quantum conductance effects at the single nanowire level.
🔍 Using both experimental and simulation showed the intrinsic relationship between electronic transport and atomic dynamic reconfiguration of the nanofilament but also elucidates deviations from integer multiples of the fundamental quantum of conductance. These deviations, influenced by peculiar dynamic trajectories of nanofilament reconfiguration and conductance fluctuations due to thermal fluctuations, offer a deeper understanding of the quantum regime in memristive devices.
Want to read the entire paper?
https://hubs.ly/Q02mGbjb0 |
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Generally, industrial catalytic reactions occur under high pressure and temperature conditions. The temperatures used in these reactions are so high that catalyst particles may undergo phase transitions consequently increasing or decreasing the catalytic activity of the catalyst. In contrast to monometallic catalysts such as Pt, multimetallic (bi-, tri-, etc.) have large number of microstates each with unique set of properties with compositional and structural degrees of freedom. Therefore, it becomes extremely important to understand the structural evolution in these materials under external stimuli simulating the real reaction conditions.
Researchers from University of Minnesota and Korea Research Institute of Chemical Technology (KRICT) used atomic-resolution operando STEM investigations to understand the phase transition and structural evolution in PtₓSnᵧ bimetallic thin films. They uncovered that how the parent phase directs the phase transitions between different solid state phases. When PtSn₄ is heated to 150°C, anisotropic layered structure is transformed to isotropic cubic PtSn₂ structure with intermediate two-dimensional prestructure directed by PtSn₄ structure. Isotropic cubic PtSn₂ structure further transforms to low-symmetry Pt₂Sn₃ phase having a layered structure at ≥500°C. The transformation here is again directed by the parent PtSn₂ phase. Finally, PtSn₂ to PtSn transition involves isotropic-isotropic phase transformation and atomic diffusion and rearrangements without any well defined interfacial structure. In summary, researchers observed three phase transitions involving four phases of PtₓSnᵧ bimetallic system which the kinetics strongly depending on the parent phase.
Operando atomic-resolution STEM experiments were performed on a probe-corrected Thermo Fisher Scientific Titan (S)TEM operated at 200 kV with convergence and HAADF inner collection semi-angles of 25.5 mrad and 93 mrad respectively. In-situ heating was performed using Protochips Fusion Select heating and electrical biasing holder.
This Z-contrast time sequence demonstrates the growth and anisotropic propagation of PtSn₂ slabs in PtSn₄ matrix.
Read the interesting findings published in the journal Nano Letters.
https://lnkd.in/dyWVkYFp |
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Interlayer stacking in strongly influence charge transport properties in 2D materials. Different stacking patterns (twist angles) in twisted-bilayer 2D materials can have unique impact on their electronic properties. Therefore, it is important to understand the atomic level origin of formation of Moiré superlattices in order to engineer them as per the desired device performance.
Researchers from University of Illinois Urbana-Champaign, 서울대학교 (Seoul National University) and National Institute for Materials Science investigated the thermally-induced structural evolution of twisted-bilayer transition metal dichalcogenides (TB-TMDCs) using in-situ aberration-corrected scanning transmission electron microscopy. Their investigations revealed that formation and dynamics of grain boundary defects along with the atomic dynamics result in nucleation of alignment of nanoscale bilayer domains within the Moiré supercell. The findings could help understand unanticipated properties of Moiré devices and offer routes to structure-direcred fabrication of twisted-bilayer 2D materials for optimal device performance.
In-situ STEM measurements were performed on a probe-corrected Thermo Fisher Scientific Themis Z microscope operated at 80 kV to mitigate the beam-induced knock-on damage. In-situ heating was performed using a Protochips Fusion heating and biasing holder. ADF images were acquired with probe convergence semi-angle of 25.2 mrad.
This atomic-resolution in-situ ADF time sequence demonstrates the nucleation and antiparallel alignment of a domain under in-situ heating.
Read the insightful findings published in the journal Science Advances.
https://lnkd.in/gKyhks5z |
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📖 Have you ever thought about what a structural metamorphesis of Mo-based zeolite imidazole framework-8 (Mo-ZIF-8) looks like at the nanoscale under diverse gaseous atmospheres? The authors of this newest work have looked at zeolite imidazole frameworks (ZIFs) under a reductive atmosphere using the #AtmosphereAX.
💡In this study, the structural transformation of Mo-related materials—Mo2C, Mo nanoparticles, Mo nanoclusters, and even Mo single atoms (Mo-SAs) on porous N-doped carbon (PNC) was investigated under reductive atmosphere at various temperatures.
But that's not all! Our study doesn't stop at oAbservation; it dives deep into understanding the underlying mechanisms driving this evolution. 💡📈 Besides in situ imaging, the authors also looked into the performance of Mo-related materials/PNC in the electrochemical nitrogen reduction reaction (NRR). The Mo-SA/PNC materials showed a remarkable NH3 yield rate and Faradic efficiency at a potential of -0.2 V versus reversible hydrogen electrode.
🔬These findings are great guidelines for the rational design in metal-based metal-organic frameworks and their practical application.
The video shows the decomposition of Mo-ZIF8 in a hydrogen/argon environment.
Want to read the entire paper?
Find it here!
https://hubs.li/Q02qLZRK0 |
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📖 Would you like to be able to observe a catalyst's synthesis behavior in water vapor? In this newest research by Savannah Turner, Nienke Visser, Remco Dalebout , Petra de Jongh and Krijn de Jong published in #Small, the researchers from #UtrechtUniversity looked at the role of water vapor on nickel based catalyst synthesis using our #AtmosphereAX!
🔬In this study, the influence of water vapor at the nanoscale during the reduction of a nickel phyllosilicate catalyst precursor under H2/Ar gas at 700°C was observed and compared with a dry synthesis at 500°C. The authors observed that water vapor not only suppresses and delays nucleation but also paradoxically accelerates particle growth.
☁️ As reduction progresses, water vapor plays a pivotal role in enhancing Ostwald ripening, leading to increased particle coalescence. This lead to the observed mechanism where water vapor facilitates the formation of mobile nickel hydroxide species, thereby promoting faster rates of particle growth during and after reduction.
💡 These findings deepen the understanding of catalyst synthesis dynamics, which can only be observed using nanoscale microscopy combined with gas, vapor and heating!
Find the full publication here:
https://hubs.li/Q02v82-d0 |
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문의
Email : hskim@lotiskorea.com
Tel : 010-2858-2798 |
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