Tomographic layer-by-layer analysis of epitaxial iron-silicide nanostructures by DFT-assisted STS

Matan Dascalu; Oswaldo Diéguez; Liwei D. Geng; Ranjit Pati; Yongmei M. Jin; Ilan Goldfarb

doi:10.1016/j.apsusc.2019.143583

Tomographic layer-by-layer analysis of epitaxial iron-silicide nanostructures by DFT-assisted STS

Matan Dascalu, Oswaldo Diéguez, Liwei D. Geng, Ranjit Pati, Yongmei M. Jin, Ilan Goldfarb

Department of Materials Science and Engineering

Research output: Contribution to journal › Article › peer-review

Abstract

Surface science techniques (STM, STS, and XPS) were combined with ab initio simulations to detect the local crystal structure and chemistry. Solid phase epitaxy of iron on vicinal Si(111) substrate resulted in the formation of 3×3R30° nanoislands and (2×2) films of γ-FeSi₂(111). We identify these structures by comparing experimental normalized derivative conductance curves with tomographic simulated local density of states (LDOS). The thermodynamic tendency of γ-FeSi₂(111) towards Si rich surfaces is manifested in Si rich termination layers and reconstructions. We show that a weighted average of the LDOS from the Fe layer and the reconstruction layer can explain the main states in the normalized derivative conductance curves, enabling in-situ identification of crystal structure and composition of epitaxial deposits.

Original language	English
Article number	143583
Journal	Applied Surface Science
Volume	496
DOIs	https://doi.org/10.1016/j.apsusc.2019.143583
State	Published - 1 Dec 2019

Keywords

Density functional theory
Density of states
Epitaxial growth
Scanning tunneling microscopy and spectroscopy
Self-assembled nanostructures

Access to Document

10.1016/j.apsusc.2019.143583

Cite this

@article{91c9af972f3f4a038ce93de44dd315b8,

title = "Tomographic layer-by-layer analysis of epitaxial iron-silicide nanostructures by DFT-assisted STS",

abstract = "Surface science techniques (STM, STS, and XPS) were combined with ab initio simulations to detect the local crystal structure and chemistry. Solid phase epitaxy of iron on vicinal Si(111) substrate resulted in the formation of 3×3R30° nanoislands and (2×2) films of γ-FeSi2(111). We identify these structures by comparing experimental normalized derivative conductance curves with tomographic simulated local density of states (LDOS). The thermodynamic tendency of γ-FeSi2(111) towards Si rich surfaces is manifested in Si rich termination layers and reconstructions. We show that a weighted average of the LDOS from the Fe layer and the reconstruction layer can explain the main states in the normalized derivative conductance curves, enabling in-situ identification of crystal structure and composition of epitaxial deposits.",

keywords = "Density functional theory, Density of states, Epitaxial growth, Scanning tunneling microscopy and spectroscopy, Self-assembled nanostructures",

author = "Matan Dascalu and Oswaldo Di{\'e}guez and Geng, {Liwei D.} and Ranjit Pati and Jin, {Yongmei M.} and Ilan Goldfarb",

note = "Publisher Copyright: {\textcopyright} 2019 Elsevier B.V.",

year = "2019",

month = dec,

day = "1",

doi = "10.1016/j.apsusc.2019.143583",

language = "אנגלית",

volume = "496",

journal = "Applied Surface Science",

issn = "0169-4332",

publisher = "Elsevier",

}

TY - JOUR

T1 - Tomographic layer-by-layer analysis of epitaxial iron-silicide nanostructures by DFT-assisted STS

AU - Dascalu, Matan

AU - Diéguez, Oswaldo

AU - Geng, Liwei D.

AU - Pati, Ranjit

AU - Jin, Yongmei M.

AU - Goldfarb, Ilan

PY - 2019/12/1

Y1 - 2019/12/1

N2 - Surface science techniques (STM, STS, and XPS) were combined with ab initio simulations to detect the local crystal structure and chemistry. Solid phase epitaxy of iron on vicinal Si(111) substrate resulted in the formation of 3×3R30° nanoislands and (2×2) films of γ-FeSi2(111). We identify these structures by comparing experimental normalized derivative conductance curves with tomographic simulated local density of states (LDOS). The thermodynamic tendency of γ-FeSi2(111) towards Si rich surfaces is manifested in Si rich termination layers and reconstructions. We show that a weighted average of the LDOS from the Fe layer and the reconstruction layer can explain the main states in the normalized derivative conductance curves, enabling in-situ identification of crystal structure and composition of epitaxial deposits.

AB - Surface science techniques (STM, STS, and XPS) were combined with ab initio simulations to detect the local crystal structure and chemistry. Solid phase epitaxy of iron on vicinal Si(111) substrate resulted in the formation of 3×3R30° nanoislands and (2×2) films of γ-FeSi2(111). We identify these structures by comparing experimental normalized derivative conductance curves with tomographic simulated local density of states (LDOS). The thermodynamic tendency of γ-FeSi2(111) towards Si rich surfaces is manifested in Si rich termination layers and reconstructions. We show that a weighted average of the LDOS from the Fe layer and the reconstruction layer can explain the main states in the normalized derivative conductance curves, enabling in-situ identification of crystal structure and composition of epitaxial deposits.

KW - Density functional theory

KW - Density of states

KW - Epitaxial growth

KW - Scanning tunneling microscopy and spectroscopy

KW - Self-assembled nanostructures

UR - http://www.scopus.com/inward/record.url?scp=85071086711&partnerID=8YFLogxK

U2 - 10.1016/j.apsusc.2019.143583

DO - 10.1016/j.apsusc.2019.143583

M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???

AN - SCOPUS:85071086711

VL - 496

JO - Applied Surface Science

JF - Applied Surface Science

SN - 0169-4332

M1 - 143583

ER -

Tomographic layer-by-layer analysis of epitaxial iron-silicide nanostructures by DFT-assisted STS

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this