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Related papers: Atomic structure of Ge quantum dots on the Si(001)…

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We report scanning tunneling microscopy observations of Ge deposited on the Si(111)-7x7 surface for a sequence of sub-monolayer coverages. We demonstrate that Ge atoms replace so-called Si adatoms. Initially, the replacements are random,…

Materials Science · Physics 2007-05-23 Y. L. Wang , H. -J. Gao , H. M. Guo , Sanwu Wang , Sokrates T. Pantelides

A new approach to solve quasicrystalline atomic structures in 3-dimensional (3D) real space is presented: The atomic pair distribution function (PDF) of face centred icosahedral Ho9Mg26Zn65 [a(6D) = 2x5.18(3)A was obtained from in-house…

Materials Science · Physics 2007-05-23 S. Bruehne , R. Sterzel , E. Uhrig , C. Gross , W. Assmus

We discuss the structural properties and optical response of a small Na cluster inside rare gas (RG) matrices of Ne, Ar, or Kr atoms. The mixed systems are described with a hierarchical model, treating the cluster at a quantum mechanical…

Other Condensed Matter · Physics 2007-06-25 F. Fehrer , P. M. Dinh , P. -G. Reinhard , E. Suraud

Several topics concerning nuclear structure and electromagnetic interactions of heavy nuclei are reviewed. These comprehend the deformed single-particle shell model, nuclear collective motion, symmetry breaking and approximate symmetry…

Nuclear Theory · Physics 2024-06-12 Alejandro Restrepo-Giraldo

Ge/Si structures with vertically stacked quantum dots are simulated to implement the basic elements of a quantum computer for operation with electron spin states. Elastic-strain fields are simulated using the conjugate gradient method and…

Mesoscale and Nanoscale Physics · Physics 2016-01-05 Yu. N. Morokov , M. P. Fedoruk , A. V. Dvurechenskii , A. F. Zinov'eva , A. V. Nenashev

Self-assembled Ge islands were grown on stripe-patterned Si (001) substrates by solid source molecular beam epitaxy. The surface morphology obtained by atomic force microscopy (AFM) and cross-sectional transmission electron microscopy…

Materials Science · Physics 2009-11-10 Zhenyang Zhong , A. Halilovic , M. Muhlberger , F. Schaffler , G. Bauer

X-ray diffuse scattering in the vicinity of a basis-forbidden (200) Bragg reflection was measured for a sample with uncapped self-assembled Ge islands epitaxially grown on Si(001). Our results provide evidence of atomically ordered SiGe…

In the Ge on Si model heteroepitaxial system, metal patterns on the silicon surface provide unprecedented control over the morphology of highly ordered Ge islands. Island shape including nanorods and truncated pyramids is set by the metal…

The electronic structure of ultra-small Au clusters on thin MgO/Ag(001) films has been analyzed by scanning tunneling spectroscopy and density functional theory. The clusters exhibit two-dimensional (2D) quantum well states, whose shapes…

Materials Science · Physics 2015-05-13 X. Lin , N. Nilius , H. -J. Freund , M. Walter , P. Frondelius , K. Honkala , H. H/"akkinen

One can confine the two-dimensional electron gas in semiconductor heterostructures electrostatically or by etching techniques such that a small electron island is formed. These man-made ``artificial atoms'' provide the experimental…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 M. Koskinen , M. Manninen , B. Mottelson , S. M. Reimann

Classical molecular dynamics simulation with embedded atom method potential had been performed to investigate the surface structure and solidification morphology of aluminum nanoclusters Aln (n = 256, 604, 1220 and 2048). It is found that…

Materials Science · Physics 2015-05-13 F. L. Tang , W. J. Lu , G. B. Chen , Y. Xie , W. Y. Yu

Mn has been found to self-assemble into atomic chains running perpendicular to the surface dimer reconstruction on Si(001). They differ from other atomic chains by a striking asymmetric appearance in filled state scanning tunneling…

Mesoscale and Nanoscale Physics · Physics 2015-12-23 R. Villarreal , M. Longobardi , S. A. Köster , Ch. J. Kirkham , D. Bowler , Ch. Renner

A structure of germanium selenide glasses is simulated by the featured clusters built from the tetrahedral GeSe4 units up to the clusters with six germanium atoms (Ge6Se16H4 and Ge6Se16H8). Quantum chemical calculations at the DFT level…

Materials Science · Physics 2017-08-23 V. Gurin , O. Shpotyuk , V. Boyko

Single layer graphene islands with a typical diameter of several nanometers were grown on a Pt (111) substrate. Scanning tunneling microscopy (STM) analysis showed most of islands are hexagonally shaped and the zigzag-type edge predominates…

Mesoscale and Nanoscale Physics · Physics 2011-01-21 Mayu Yamamoto , Seiji Obata , Koichiro Saiki

It is experimentally observed that adsorbate atoms and vacancies on (111) surfaces of fcc metals cluster into islands which are approximately hexagonal, but which on closer inspection turn out to have equilibrium facets which alternate in…

Condensed Matter · Physics 2009-10-22 G. T. Barkema , M. E. J. Newman , M. Breeman

Application of the two-wavelength X-ray reflectometry to exploration of Ge/Si(001) hereostructures with dense chains of stacked Ge quantum dots is presented

We present structure calculations of neutral and singly ionized Mg clusters of up to 30 atoms, as well as Na clusters of up to 10 atoms. The calculations have been performed using density functional theory (DFT) within the local…

Atomic and Molecular Clusters · Physics 2015-03-19 Stefan Janecek , Eckard Krotscheck , Michael Liebrecht , Roman Wahl

Analytical relationships for the surface and curvature energies of oblate and prolate semi-spheroidal atomic clusters have been obtained. By modifying the cluster shape from a spheroid to a semi-spheroid the most stable shape was changed…

Atomic and Molecular Clusters · Physics 2007-09-18 D. N. Poenaru , R. A. Gherghescu , A. V. Solov'yov , W. Greiner

Two distinct structures of aggregates of atoms connected by anisotropic bonds with a network configuration are discussed from the viewpoint of a point set topology. A specific topological space connects the two types of topological…

Mathematical Physics · Physics 2017-08-10 Shousuke Ohmori , Tomoyuki Yamamoto , Akihiko Kitada

The atomic structure of the recently discovered antiferromagnetic Ga50Pd35.5Tb14.5 2/1 approximant to quasicrystal with the space group of Pa-3(No. 205), a = 23.1449(0) angstrom was determined by means of a single crystal X-ray diffraction.…

Materials Science · Physics 2023-05-17 Farid Labib , Hiroyuki Takakura , Asuka Ishikawa , Ryuji Tamura