Small-sized metals generally exhibit unusual deformation responses subjected to cyclic loading, since their limited volume cannot effectively accommodate micro-sized dislocation patterns typically found in their bulk counterparts. Here, the cyclic behaviors in Cu nanopillars with different configurations are investigated using in situ transmission electron microscopy fatigue test. Dislocation tangles formed in single- and twinned-crystal nanopillars as a result of cycling-induced operations of multiple slip systems and further unpinning and absorption of pinned dislocations. While, nanopillars configured with low-angle grain boundary (LAGB) underwent the degradation and eventual decomposition of the LAGB due to the cycling-induced emission of grain boundary dislocations, which resulted in high-density mobile dislocations to withstand the cyclic loading. These findings contribute to a systematic and comprehensive understanding of the micro-mechanics of dislocation-related phenomena in the cyclic response of nanoscale metals.
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http://dx.doi.org/10.1002/smll.202406130 | DOI Listing |
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December 2024
Center of Electron Microscopy, State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, China.
J Colloid Interface Sci
November 2024
Tianjin Key Laboratory of Chemical Process Safety, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China; Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin 300071, China. Electronic address:
It is critical and challenging to develop highly active and low cost bifunctional electrocatalysts for the hydrogen/oxygen evolution reaction (HER/OER) in water electrolysis. Herein, we propose cerium-vanadium-based hollow nanopillar arrays supported on nickel foam (CeV-HNA/NF) as bifunctional HER/OER electrocatalysts, which are prepared by etching the V metal-organic framework with Ce salt and then pyrolyzing. Etching results in multidimensional optimizations of electrocatalysts, covering substantial oxygen vacancies, optimized electronic configurations, and an open-type structure of hollow nanopillar arrays, which contribute to accelerating the charge transfer rate, regulating the adsorption energy of H/O-containing reaction intermediates, and fully exposing the active sites.
View Article and Find Full Text PDFPhys Rev Lett
June 2024
Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Solid-state spin qubits are promising candidates for quantum information processing, but controlled interactions and entanglement in large, multiqubit systems are currently difficult to achieve. We describe a method for programmable control of multiqubit spin systems, in which individual nitrogen-vacancy (NV) centers in diamond nanopillars are coupled to magnetically functionalized silicon nitride mechanical resonators in a scanning probe configuration. Qubits can be entangled via interactions with nanomechanical resonators while programmable connectivity is realized via mechanical transport of qubits in nanopillars.
View Article and Find Full Text PDFMetasurfaces made of subwavelength silicon nanopillars provide unparalleled capacity to manipulate light, and have emerged as one of the leading platforms for developing integrated photonic devices. In this study, we report on a compact, passive approach based on planar metasurface optics to generate large optical trap arrays. The unique configuration is achieved with a meta-hologram to convert a single incident laser beam into an array of individual beams, followed up with a metalens to form multiple laser foci for single rubidium atom trapping.
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