A survey of published literature reveals a difference in the density of amorphous and crystalline solids (organic and inorganic) on the order of 10%-15%, whereas for metallic alloys, it is found to be typically less than 5%. Standard geometric models of atomic packing can account for the polymeric and inorganic glasses without requiring changes in interatomic separations (bond lengths). By contrast, the relatively small difference in density between crystalline and glassy metals (and metallic alloys) implies variations in interatomic separations due to merging orbitals giving rise to reduced atomic volumes. To test this hypothesis, quantum density functional theory computations were carried out on ordered and irregular clusters of aluminum. The results point to decreasing interatomic distances with decreasing coordination, from which one can deduce that the geometrical method of random hard sphere packing significantly underestimates the densities of amorphous metallic alloys.
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http://dx.doi.org/10.1063/1.5113733 | DOI Listing |
Nat Commun
January 2025
Analytical Engineering Group, Samsung Advanced Institute of Technology, 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do, Republic of Korea.
To reliably operate anode-less solid-state Li metal batteries, wherein precipitated Li acts as the anode, stabilizing the interface between the solid electrolyte and electrode is crucial. The interface can be controlled by a metal interlayer on the electrolyte to form a Li alloy buffer that facilitates stable Li plating/stripping, thereby mitigating the loss of physical contact and preventing short circuits. However, the mechanism governing stable Li plating/stripping in the metal interlayer without degrading battery materials remains unclear owing to an incomplete understanding of the dynamic and complex electrochemical reactions in the solid state.
View Article and Find Full Text PDFActa Bioeng Biomech
September 2024
Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw, Poland.
The aim of the study was to investigate the influence of the nitrocarburizing process carried out in low temperature plasma using the active screen at 440 °C on the structure and physicochemical properties of the 316LVM steel. In the paper, results of micro-structure and phase composition of the layers, roughness, and surface wettability, potentiodynamic pitting corrosion resistance, penetration of ions into the solution as well as biological tests were present. The studies were conducted for the samples of both mechanically polished and nitrocarburized surfaces, after sterilization, and exposure to the Ringer's solution.
View Article and Find Full Text PDFActa Bioeng Biomech
September 2024
Department of Mechanics, Materials and Biomedical Engineering, Faculty of Mechanical Engineering, Wrocław University of Science and Technology, Wrocław, Poland.
: The aim of this study was to evaluate the abrasive wear of the sliding screw-rod joint used in growth guidance system (GGS) stabilizers, allowing for the translation of the screw along the rod during the spinal growth process in a standard and modified system. : The study used single kinematic screw-rod pairs made of titanium alloy Ti6Al4V. Mechanical tests (cyclic loads) simulated the stabilizer's operation under conditions similar to actual use.
View Article and Find Full Text PDFFoot Ankle Int
January 2025
Royal National Orthopaedic Hospital NHS Trust, Foot & Ankle Unit, Stanmore, United Kingdom.
Background: Ankle and hindfoot fusion in the presence of large bony defects represents a challenging problem. The purpose of this study was to evaluate outcomes of patients who underwent ankle-hindfoot fusions with impaction bone grafting (IBG) with morselized femoral head allograft to fill large bony void defects.
Methods: This was a 3-center, retrospective review of a consecutive series of 49 patients undergoing ankle or hindfoot fusions with femoral head IBG for filling large bony defects.
Nanoscale
January 2025
Department of Chemistry and Centre for Atomic Engineering of Advanced Materials, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, Anhui University, Hefei, Anhui 230601, P. R. China.
Investigating the impact of heteroatom alloying extents on regulating the cluster structures is crucial for the fabrication of cluster-based nanomaterials with customized properties. Herein, two structurally comparable PdAu ( = 1, 2) nanoclusters with a uniform surface environment but completely distinct kernel configurations were controllably synthesized and structurally determined. The single Pd-alloyed Pd1Au12 nanocluster retained an icosahedral metal framework, while the Pd2Au12 nanocluster with two Pd heteroatoms exhibited a unique toroidal configuration.
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