Magnetism has recently been observed in nominally nonmagnetic iron disilicide in the form of epitaxial γ-FeSi nanostructures on Si(111) substrate. To explore the origin of the magnetism in γ-FeSi/Si(111) nanostructures, we performed a systematic first-principles study based on density functional theory. Several possible factors, such as epitaxial strain, free surface, interface, and edge, were examined. The calculations show that among these factors, only the edge can lead to the magnetism in γ-FeSi/Si(111) nanostructures. It is shown that magnetism exhibits a strong dependency on the local atomic structure of the edge. Furthermore, magnetism can be enhanced by creating multiple-step edges. In addition, the results also reveal that edge orientation can have a significant effect on magnetism. These findings, thus, provide insights into a strategy to tune the magnetic properties of γ-FeSi/Si(111) nanostructures through controlling the structure, population, and orientation of the edges.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8066300 | PMC |
http://dx.doi.org/10.3390/nano11040849 | DOI Listing |
Nanotechnology
January 2025
Laboratory of micro- and nanoelectronics, Saint Petersburg Electrotechnical University 'LETI', Prof. Popova st. 5, 197022 St.Petersburg, Russia.
The processes of electrochemical deposition of Ni on vertically aligned GaAs nanowires (NWs) grown by molecular-beam epitaxy (MBE) using Au as a growth catalyst on n-type Si(111) substrates were studied. Based on the results of electrochemical deposition, it was concluded that during the MBE synthesis of NWs the self-induced formation of conductive channels can occur inside NWs, thereby forming quasi core-shell NWs. Depending on the length of the channel compare to the NW heights and the parameters of electrochemical deposition, the different hybrid metal-semiconductor nanostructures, such as Ni nanoparticles on GaAs NW side walls, Ni clusters on top ends of GaAs NWs, core-shell GaAs/Ni NWs, were obtained.
View Article and Find Full Text PDFStruct Dyn
March 2024
Department of Physics and Center for Nanointegration CENIDE, University of Duisburg-Essen, Lotharstrasse. 1, 47057 Duisburg, Germany.
Many fundamental processes of structural changes at surfaces occur on a pico- or femtosecond timescale. In order to study such ultrafast processes, we have combined modern surface science techniques with fs-laser pulses in a pump-probe scheme. Grazing incidence of the electrons ensures surface sensitivity in ultrafast reflection high-energy electron diffraction (URHEED).
View Article and Find Full Text PDFAcc Chem Res
July 2023
Department of Chemistry and Graduate Center for Materials Research, Missouri University of Science and Technology, Rolla, Missouri 65409-1170, United States.
ConspectusThe quality of technological materials generally improves as the crystallographic order is increased. This is particularly true in semiconductor materials, as evidenced by the huge impact that bulk single crystals of silicon have had on electronics. Another approach to producing highly ordered materials is the epitaxial growth of crystals on a single-crystal surface that determines their orientation.
View Article and Find Full Text PDFInt J Mol Sci
December 2022
Institute of Nanotechnologies, Electronics and Equipment Engineering, Southern Federal University, Taganrog 347922, Russia.
This paper presents the results of experimental studies of the effect of Si(111) surface modification by Ga-focused ion beam (FIB) at 30 kV accelerating voltage on the features of the epitaxial GaAs nanowire (NW) growth processes. We experimentally established the regularities of the Ga ions' dose effect during surface modification on the structural characteristics of GaAs NW arrays. Depending on the Ga ion dose value, there is one of three modes on the surface for subsequent GaAs NW growth.
View Article and Find Full Text PDFPhys Chem Chem Phys
May 2023
Departments of Chemistry and of Physics, Quantum Theory Project, University of Florida, Gainesville, Florida 32611, USA.
Metal clusters with 10 to 100 atoms supported by a solid surface show electronic structure typical of molecules and require treatments starting from their atomic structure, and they also can display collective electronic phenomena similar to plasmons in metal solids. We have employed electronic structure results from two different density functionals (PBE and the hybrid HSE06) and a reduced density matrix treatment of the dissipative photodynamics to calculate light absorbance by the large Ag clusters Ag, = 33, 37(open shell) and = 32, 34 (closed shell), adsorbed at the Si(111) surface of a slab, and forming nanostructured surfaces. Results on light absorption are quite different for the two functionals, and are presented here for light absorbances using orbitals and energies from the hybrid functional giving correct energy band gaps.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!