NanoScale Corporation (United States)

An XGBoost regression model has been utilized to accurately predict the temperature-dependent thermal conductivity (κ), electrical conductivity (σ), Seebeck coefficient (S), and figure of merit (ZT) of skutterudite materials from 50 to 1000 K. Shapley values, derived from cooperative game theory, were employed to quantify the contributions of various material descriptors, providing valuable insights into the underlying correlations and trade-offs between different features and thermoelectric properties. The analysis revealed crucial factors influencing the thermoelectric performance of skutterudites, including temperature, compositional attributes, electronic configurations, and structural properties. The model predicts a room-temperature ZT of approximately 0.45 for Nd(CoP3)4, a promising thermoelectric material that has not yet been experimentally investigated. In addition, the prediction of half-metallic ferromagnetic behavior in Nd(CoP3)4 by first-principles density functional theory (DFT) with Hubbard corrections has led to the investigation of its thermoelectric properties. At elevated temperatures, a strong correlation was observed between XGBoost predictions and DFT calculations for the σ and S of Nd(CoP3)4. The agreement between predicted and calculated values was less pronounced, though still reasonable, for κ and ZT. By integrating machine learning with fundamental materials science principles, this study paves the way for accelerated discovery and optimization of high-performance thermoelectric materials, contributing to the advancement of sustainable energy technologies and the pursuit of a more energy-efficient future.

The performance of bimetallic dilute alloy catalysts is largely determined by the size of minority metal ensembles on the nanoparticle surface. By analyzing the synthesis of catalysts comprising Pd8Au92 nanoparticles supported on silica using surface-sensitive techniques, we report that whether Pd overgrowth occurs before or after Au nanoparticle deposition onto the support controls the surface Pd ensemble size and abundance. These differences in Pd ensembles influence catalytic reactivity in H2–D2 isotope exchange and benzaldehyde hydrogenation, which, in correlation with theoretical calculations, is used to elucidate the active site(s) in each reaction. To clarify how the synthetic sequence controls the formation of Pd ensembles, we combine numerical wetting calculations and molecular dynamics simulations (with a machine-learned force field) to visualize Pd deposition and migration on the nanoparticle surface, respectively. Our results suggest that the nanoparticle–support interface restricts nanoparticle accessibility to Pd deposition, which consequently controls the Pd ensemble size, illustrating the critical role of nanoscale wetting phenomena during bimetallic catalyst preparation.

Exchange-coupled interfaces are pivotal in exploiting two-dimensional (2D) ferromagnetism. Due to the extraordinary correlations among charge, spin, orbital and lattice degrees of freedom, layered magnetic transition metal chalcogenides (TMCs) bode well for exotic topological phenomena. Here we report the realization of wafer-scale Cr2Te3down to monolayer (ML) on insulating SrTiO3(111) and/or Al2O3(001) substrates using molecular beam epitaxy. Robust ferromagnetism persists in the 2D limit. In particular, the Curie temperatureTCof 2 ML Cr2Te3increases from 100 K to ∼120 K when proximitized to topological insulator (TI) (Bi,Sb)2Te3, with substantially boosted magnetization as observed via polarized neutron reflectometry. Our experiments and theory strongly indicate that the Bloembergen-Rowland interaction is likely universal underlyingTCenhancement in TI-coupled magnetic heterostructures. The topological-surface-enhanced magnetism in 2D TMC enables further exchange coupling physics and quantum hybrid studies, including paving the way to realize interface-modulated topological electronics.

While great progress is being made in achieving high power conversion efficiency (PCE), durability, and reliability in rigid and flexible n–i–p perovskite solar cells (PSCs), there is still room for improvement. Among myriad ways this can be achieved, one way is to improve the processing and quality of electron transport layers (ETLs) used in PSCs. To that end, here we explore the use of SnO2/TiO2 bilayer ETLs in both rigid and flexible PSCs. In the case of rigid PSCs, chemical bath deposition (CBD) is used where the bilayer architecture affords the CBD of high‐quality ETL, which results in PSCs with up to 25.13% PCE and operational stability T 80 (80% of initial PCE retained) of 2220 h under 1‐sun continuous illumination with maximum power‐point tracking. In the case of flexible PSCs, once again, the bilayer architecture allows us to fabricate high‐quality ETL using spin coating, which results in PSCs with up to 22.54% PCE and excellent mechanical durability, withstanding 20 000 bending cycles with ≈92% of the initial PCE retained. Mechanisms underlying the enhanced performance and stability/durability of rigid and flexible PSCs that use SnO2/TiO2 bilayer ETLs are elucidated. This approach could be extended to other ETL systems for PSCs for further improvements in PCE, durability, and reliability.

Metallophthalocyanine (MPc)-linked conductive two-dimensional (2D) metal-organic frameworks (MOFs) hold tremendous promise as modular 2D materials in sensing, catalysis, and energy-related applications due to their combinatory bimetallic system from the MPc core and bridging metal nodes, endowing them with high electrical conductivity and multifunctionality. Despite significant advances, there is a gap in fundamental understanding regarding the periodic effects of metal nodes on the structural properties of MPc-linked 2D MOFs. Herein, we report a series of highly crystalline MOFs wherein copper phthalocyanine (CuPc) is linked with Ni, Cu, and Zn nodes (CuPc-O-M, M: Ni, Cu, Zn). The prepared CuPc-O-M MOFs exhibit p-type semiconducting properties with an exceptionally high range of electrical conductivity. Notably, the differences in the 3d orbital configurations of the Ni, Cu, and Zn nodes in CuPc-O-M MOFs lead to perturbations of the interlayer stacking patterns of the 2D framework materials, which ultimately affect material properties, such as semiconducting band gaps and charge transport within the framework. The Cu2+ (3d9) metal node within the eclipsed interlayer stacking of CuPc-O-Cu MOF demonstrates excellent charge transport, which results in the smallest band gap of 1.14 eV and the highest electrical conductivity of 9.3 S m-1, while the Zn2+ (3d10) metal node within CuPc-O-Zn results in a slightly inclined interlayer stacking, leading to the largest band gap of 1.27 eV and the lowest electrical conductivity of 2.9 S m-1. These findings form an important foundation in the strategic molecular design of this class of materials for multifaceted functionality that builds upon the electronic properties of these materials.

Fibrin has unique biomechanical properties which are essential for its role as a scaffold for blood clots. Fibrin is highly extensible and demonstrates significant strain stiffening behaviour, which is essential for stress-distribution in the network. Yet the exact structures of fibrin at the sub-fibre level that contribute to its unique biomechanical characteristic are unknown. Here we show how truncations of the fibrinogen αC-region impact the biomechanical properties of fibrin fibres. Surprisingly, absence of the complete αC-region did not influence the low strain modulus of fibrin fibres but led to premature fibre rupture and decreased extensibility. Intermediate effects were observed with partial deletion of the αC-region, reflected by intermediate rupture stress and toughness. However, overall strain-stiffening behaviour remained even in absence of the αC-region, indicating that strain stiffening is not due to stress being transferred from the αC-region to the protofibril backbone. Upon stress-relaxation, decay constants and their relative contribution to the total relaxation remained similar at all strains, showing that a distinct relaxation process is present until fibre rupture. However, relative contribution of fast relaxation was maximal only in crosslinked fibres if the flexible αC-connector was present. These data show that the αC-region is not the main load-bearing structure within fibrin fibres and point to a critical role for the protofibril backbone instead. We present a revised structural model based on protofibril branching that fully explains the unique biomechanical behaviour of fibrin fibres, while the αC-region primarily acts as a safety latch at the highest of strains. Statement of SignificanceThe findings presented in this paper reveal critically important details about how the molecular structure of fibrin contributes to its unique mechanical properties which are essential to fulfil its function as the scaffold of blood clots. In this work we used engineered proteins with alterations in an important but highly disordered area of the molecule called αC-region and we provide direct evidence for the first time for how the absence of either the globular αC-domain, or the complete αC-region impacts the mechanical behaviour of individual fibrin fibres. Using these results we developed a new structural model of protofibril organisation within fibrin fibres that fully explains their strain stiffening, relatively low modulus and their high, largely variable, extensibility.

Quantum geometry in condensed-matter physics has two components: the real part quantum metric and the imaginary part Berry curvature. Whereas the effects of Berry curvature have been observed through phenomena such as the quantum Hall effect in two-dimensional electron gases and the anomalous Hall effect (AHE) in ferromagnets, the quantum metric has rarely been explored. Here, we report a nonlinear Hall effect induced by the quantum metric dipole by interfacing even-layered MnBi2Te4 with black phosphorus. The quantum metric nonlinear Hall effect switches direction upon reversing the antiferromagnetic (AFM) spins and exhibits distinct scaling that is independent of the scattering time. Our results open the door to discovering quantum metric responses predicted theoretically and pave the way for applications that bridge nonlinear electronics with AFM spintronics.