The growth mode of small Ni clusters evaporated in UHV on HOPG has been investigated by scanning tunnelling microscopy. The size, the size distribution, and the shape of the clusters have been evaluated for different evaporation conditions and annealing temperatures. The total coverage of the surface strongly depends on the evaporation rate and time, whereas the influence of these parameters is low on the cluster size. Subsequent stepwise annealing has been performed. This results in a reduction of the total amount of the Ni clusters accompanied by a decreasing in the overall coverage of the surface. The diameter of the clusters appears to be less influenced by the annealing than is their height. Besides this, the cluster shape is strongly influenced, changing to a quasi-hexagonal geometry after the first annealing step, indicating single-crystal formation. Finally, a reproducible methodology for picking up individual clusters is reported [1].
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http://dx.doi.org/10.3762/bjnano.4.48 | DOI Listing |
Phys Rev Lett
December 2024
Massachusetts Institute of Technology, Research Laboratory of Electronics, Cambridge, Massachusetts 02139, USA.
Classical transport of electrons and holes in nanoscale devices leads to heating that severely limits performance, reliability, and efficiency. In contrast, recent theory suggests that interband quantum tunneling and subsequent thermalization of carriers with the lattice results in local cooling of devices. However, internal cooling in nanoscale devices is largely unexplored.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Brookhaven National Laboratory, Condensed Matter Physics and Materials Science Division, Upton, New York 11973, USA.
We present a protocol for detecting multipartite entanglement in itinerant many-body electronic systems using single-particle Green's functions. To achieve this, we first establish a connection between the quantum Fisher information and single-particle Green's functions by constructing a set of witness operators built out of single electron creation and destruction operators in a doubled system. This set of witness operators is indexed by a momentum k.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
CEITEC-Central European Institute of Technology, Brno University of Technology, Purkyňova 123, Brno 61200, Czech Republic.
Detailed atomic-scale understanding is a crucial prerequisite for rational design of next-generation single-atom catalysts (SACs). However, the sub-ångström precision needed for systematic studies is challenging to achieve on common SACs. Here, we present a two-dimensional (2D) metal-organic system featuring Fe-N single-atom sites, where the metal-organic structure is modulated by 0.
View Article and Find Full Text PDFJ Phys Condens Matter
January 2025
Department of Physics, Lund University, BOX 118, Lund, 221 00, SWEDEN.
In recent years, studies of surfaces at more realistic conditions has advanced significantly, leading to an increased understanding of surface dynamics under reaction conditions. The development has mainly been due to the development of new experimental techniques or new experimental approaches. Techniques such as High Pressure Scanning Tunneling/Force Microscopy (HPSTM/HPAFM), Ambient Pressure X-ray Photo emission Spectroscopy (APXPS), Surface X-Ray Diffraction (SXRD), Polarization-Modulation InfraRed Reflection Absorption Spectroscopy (PMIRRAS) and Planar Laser Induced Fluorescence (PLIF) at semi-realistic conditions has been used to study planar model catalysts or industrial materials under operating conditions.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 201210, China.
The emergence of spinon quasiparticles, which carry spin but lack charge, is a hallmark of collective quantum phenomena in low-dimensional quantum spin systems. While the existence of spinons has been demonstrated through scattering spectroscopy in ensemble samples, real-space imaging of these quasiparticles within individual spin chains has remained elusive. In this study, we construct individual Heisenberg antiferromagnetic spin-1/2 chains using open-shell [2]triangulene molecules as building blocks.
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