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The behavior of individual nanocrystals during superlattice phase transitions can profoundly affect the structural perfection and electronic properties of the resulting superlattices. However, details of nanocrystal morphological changes during superlattice phase transitions are largely unknown due to the lack of direct observation. Here, we report the dynamic deformability of PbSe semiconductor nanocrystals during superlattice phase transitions that are driven by ligand displacement. Real-time high-resolution imaging with liquid-phase transmission electron microscopy reveals that following ligand removal, the individual PbSe nanocrystals experience drastic directional shape deformation when the spacing between nanocrystals reaches 2 to 4 nm. The deformation can be completely recovered when two nanocrystals move apart or it can be retained when they attach. The large deformation, which is responsible for the structural defects in the epitaxially fused nanocrystal superlattice, may arise from internanocrystal dipole-dipole interactions.
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http://dx.doi.org/10.1126/sciadv.aaw5623 | DOI Listing |
Cryst Growth Des
September 2025
Department of Applied Physics, Eindhoven University of Technology, Groene Loper 19, Eindhoven 5612AP, The Netherlands.
Crystal phase control of III-V semiconductor nanowires grown by the vapor liquid solid mechanism has emerged as a new frontier in nanomaterials in the 2010s. Of particular interest is the ability to grow the metastable wurtzite crystal, which is commercially unavailable in semiconductors such as GaAs and SiGe. The successful growth of wurtzite GaAs nanowires has been demonstrated by precise control of the wetting contact angle of the catalyst particle.
View Article and Find Full Text PDFACS Nano
September 2025
Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
As a versatile platform for exploring exotic quantum phases, moiré superlattices, ranging from twisted graphene to twisted transition metal dichalcogenides, have been intensively studied. In this work, based on exact diagonalization and Hartree-Fock mean-field calculations, the interaction-driven topological phases are investigated in hole-doped twisted bilayer MoS at the high filling factor = 3. Besides the nematic insulator and quantum anomalous Hall phases, the topological Wigner molecule crystal (TWMC) phase is found in the phase diagram.
View Article and Find Full Text PDFACS Nano
September 2025
Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland.
Nanocrystals (NCs) of various compositions have made important contributions to science and technology, with their impact recognized by the 2023 Nobel Prize in Chemistry for the discovery and synthesis of semiconductor quantum dots (QDs). Over four decades of research into NCs has led to numerous advancements in diverse fields, such as optoelectronics, catalysis, energy, medicine, and recently, quantum information and computing. The last 10 years since the predecessor perspective "Prospect of Nanoscience with Nanocrystals" was published in ACS Nano have seen NC research continuously evolve, yielding critical advances in fundamental understanding and practical applications.
View Article and Find Full Text PDFNano Lett
September 2025
Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, California 90095, United States.
Moiré superlattices introduce new length and energy scales, enabling discoveries, such as unconventional superconductivity, in 2D systems. This concept has recently been extended to bulk materials with multiple- spin textures, opening exciting opportunities for spin moiré physics. A notable example is EuAgSb, where a spin moiré superlattice (SMS), manifested as a double- spin modulation, induces a superzone gap opening.
View Article and Find Full Text PDFJ Am Chem Soc
August 2025
Department of Chemistry, University of California, Berkeley, California 94720, United States.
The interplay between symmetry and topology in magnetic materials makes it possible to engineer exotic phases and technologically useful properties. A key requirement for these pursuits is achieving control over local crystallographic and magnetic structure, usually through sample morphology (such as synthesis of bulk crystals versus thin films) and application of magnetic or electric fields. Here we show that VNbS can be crystallized in two ordered superlattices, distinguished by the periodicity of out-of-plane magnetic intercalants.
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