Toma Susi

Toma Susi
University of Vienna | UniWien · Physics of Nanostructured Materials Group

D.Sc. (Tech)

About

162
Publications
29,086
Reads
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2,870
Citations
Citations since 2016
127 Research Items
2588 Citations
20162017201820192020202120220100200300400500600
20162017201820192020202120220100200300400500600
20162017201820192020202120220100200300400500600
20162017201820192020202120220100200300400500600
Introduction
"Poised midway between the unvisualizable cosmic vastness of curved spacetime and the dubious, shadowy flickerings of charged quanta, we human beings, more like rainbows and mirages than like raindrops or boulders, are unpredictable self-writing poems -- vague, metaphorical, ambiguous, and sometimes exceedingly beautiful." -Douglas Hofstadter "In science one tries to tell people, in such a way as to be understood by everyone, something that no one ever knew before. But in poetry, its the exact opposite." -P.A.M. Dirac "God is our chosen name for the ceaseless creativity in the natural universe, biosphere, and human cultures." -Stuart A. Kauffman "Love is the only emotion that enhances our intelligence." -Humberto Maturana
Additional affiliations
April 2016 - present
University of Vienna
Position
  • Lecturer
Description
  • Spectroscopy and Microscopy (spectroscopy part)
September 2013 - August 2015
University of Vienna
Position
  • FWF Lise Meitner fellow
June 2011 - August 2013
Aalto University
Position
  • PostDoc Position
Education
January 2008 - June 2011
Aalto University
Field of study
  • Nanomaterials
September 2002 - January 2008
Aalto University
Field of study
  • Materials Science

Publications

Publications (162)
Article
Machine learning and artificial intelligence (ML/AI) are rapidly becoming an indispensable part of physics research, with applications ranging from theory and materials prediction to high-throughput data analysis. In parallel, the recent successes in applying ML/AI methods for autonomous systems from robotics through self-driving cars to organic an...
Article
Full-text available
The manipulation of individual atoms has developed from visionary speculation into an established experimental science. Using focused electron irradiation in a scanning transmission electron microscope instead of a physical tip in a scanning probe microscope confers several benefits, including thermal stability of the manipulated structures, the ab...
Article
We introduce a novel method to improve the computational efficiency for (S)TEM image simulation by employing matrix diagonalization of the mixed envelope function (MEF). The MEF is derived by taking the finite size and the energy spread of the effective electron source into account, and is a component of the transmission cross-coefficient that acco...
Article
We compare the ion-induced electron emission from freestanding monolayers of graphene and MoS2 to find a sixfold higher number of emitted electrons for graphene even though both materials have similar work functions. An effective single-band Hubbard model explains this finding by a charge-up in MoS2 that prevents low energy electrons from escaping...
Article
Full-text available
We present a quantitatively accurate machine-learning (ML) model for the computational prediction of core-electron binding energies, from which X-ray photoelectron spectroscopy (XPS) spectra can be readily obtained. Our model combines density functional theory (DFT) with GW and uses kernel ridge regression for the ML predictions. We apply the new a...
Article
Full-text available
Transmission electron microscopy characterization may damage materials, but an electron beam can also induce interesting dynamics. Elastic knock-on is the main electron irradiation damage mechanism in metals including graphene, and although atomic vibrations influence its cross section, only the out-of-plane direction has been considered so far. He...
Article
Although surface diffusion is critical for many physical and chemical processes, including the epitaxial growth of crystals and heterogeneous catalysis, it is particularly challenging to directly study. Here, we estimate the carbon adatom migration barrier on freestanding monolayer graphene by quantifying its temperature-dependent electron knock-on...
Article
Substituting heteroatoms into graphene can tune its properties for applications ranging from catalysis to spintronics. The further recent discovery that covalent impurities in graphene can be manipulated at atomic precision using a focused electron beam may open avenues towards sub-nanometer device architectures. However, the preparation of clean s...
Article
Full-text available
Heterostructures composed of two-dimensional (2D) materials are already opening many new possibilities in such fields of technology as electronics and magnonics, but far more could be achieved if the number and diversity of 2D materials is increased. So far, only a few dozen 2D crystals have been extracted from materials that exhibit a layered phas...
Preprint
Although surface diffusion is critical for many physical and chemical processes, including the epitaxial growth of crystals and heterogeneous catalysis, it is particularly challenging to directly study. Here, we estimate the carbon adatom migration barrier on freestanding monolayer graphene by quantifying its temperature-dependent electron knock-on...
Article
As a one-atom thick, mechanically strong, and chemically stable material with unique electronic properties, graphene can serve as the basis for a large number of applications. One way to tailor its properties is the controlled introduction of covalently bound heteroatoms into the lattice. In this study, we demonstrate efficient implantation of indivi...
Preprint
Full-text available
Doping of the graphene lattice with transition metal atoms resulting in high magnetic anisotropy energy (MAE) is an important goal of materials research owing to its potential application in spintronics. In this article, by using spin-polarized density functional theory including spin-orbit coupling, we examined magnetic properties of graphene with...
Preprint
We present a quantitatively accurate machine-learning (ML) model for the computational prediction of core-electron binding energies, from which x-ray photoelectron spectroscopy (XPS) spectra can be readily obtained. Our model combines density functional theory (DFT) with $GW$ and uses kernel ridge regression for the ML predictions. We apply the new...
Preprint
Full-text available
Elastic knock-on is the main electron irradiation damage mechanism in metals including graphene. Atomic vibrations influence its cross-section, but only the out-of-plane direction has been considered so far in the literature. Here, we present a full three-dimensional theory of knock-on damage including the effect of temperature and vibrations to de...
Article
Full-text available
A major factor underlying several of scholarship's most pressing problems is its antiquated journal system with its trifecta of reproducibility, affordability and functionality crises. Any solution needs to not only solve the current problems but also be capable of preventing a takeover by corporations. Technically, there is broad agreement on the...
Preprint
Full-text available
Heterostructures composed of two-dimensional (2D) materials are already opening many new possibilities in such fields of technology as electronics and magnonics, but far more could be achieved if the number and diversity of 2D materials is increased. So far, only a few dozen 2D crystals have been extracted from materials that exhibit a layered phas...
Article
Full-text available
Diamond and graphene are carbon allotropes with starkly different physical characteristics. Their combination into graphene-on-diamond heterostructures could benefit from the complementary properties of both components. Graphitization of single-crystalline diamond surfaces is a promising synthesis route, but a clear understanding of the growth of g...
Article
Full-text available
Single atoms and few-atom nanoclusters are of high interest in catalysis and plasmonics, but pathways for their fabrication and placement remain scarce. We report here the self-assembly of room-temperature-stable single indium (In) atoms and few-atom In clusters (2–6 atoms) that are anchored to substitutional silicon (Si) impurity atoms in suspende...
Article
Full-text available
The precise positioning of dopant atoms within bulk crystal lattices could enable novel applications in areas including solid-state sensing and quantum computation. Established scanning probe techniques are capable tools for the manipulation of surface atoms, but at a disadvantage due to their need to bring a physical tip into contact with the samp...
Article
The electronic properties of stacked few‐layer 2D materials are highly dependent on their precise structural arrangement. In article number 2100388, featured on the front cover, Michael J. Zachman, Miaofang Chi, and co‐workers describe a four‐dimensional scanning transmission electron microscopy technique that utilizes interference between Bragg di...
Preprint
Full-text available
The precise positioning of dopant atoms within bulk crystal lattices could enable novel applications in areas including solid-state sensing and quantum computation. Established scanning probe techniques are capable tools for the manipulation of surface atoms, but at a disadvantage due to their need to bring a physical tip into contact with the samp...
Article
Full-text available
Structural engineering is the first step toward changing properties of materials. While this can be at relative ease done for bulk materials, for example, using ion irradiation, similar engineering of 2D materials and other low-dimensional structures remains a challenge. The difficulties range from the preparation of clean and uniform samples to th...
Article
Full-text available
Processes of research evaluation are coming under increasing scrutiny, with detractors arguing that they have adverse effects on research quality, and that they support a research culture of competition to the detriment of collaboration. Based on three personal perspectives, we consider how current systems of research evaluation lock early career r...
Article
Van der Waals materials composed of stacks of individual atomic layers have attracted considerable attention due to their exotic electronic properties that can be altered by, e.g., manipulating the twist angle of bilayer materials or the stacking sequence of trilayer materials. To fully understand and control the unique properties of these few-laye...
Article
Simulation of transmission electron microscopy (TEM) images or diffraction patterns is often required to interpret experimental data. Since nuclear cores dominate electron scattering, the scattering potential is typically described using the independent atom model, which completely neglects valence bonding and its effect on the transmitting electro...
Article
Full-text available
Transmission electron microscopy (TEM) and scanning TEM (STEM) are indispensable tools for materials characterization. However, during a typical (S)TEM experiment, the sample is subject to a number of effects that can change its atomic structure. Of these, perhaps the least discussed are chemical modifications due to the non-ideal vacuum around the...
Article
Full-text available
Vertically stacked low-dimensional heterostructures are outstanding systems both for exploring fundamental physics and creating new devices. Due to nanometerscale building blocks, atomic scale phenomena become for them of fundamental importance, including during device operation. These can be accessed in situ in aberration-corrected scanning transm...
Article
Simulation of transmission electron microscopy (TEM) images or diffraction patterns is often required to interpret experimental data. Since nuclear cores dominate electron scattering, the scattering potential is typically described using the independent atom model, which completely neglects valence bonding and its effect on the transmitting electro...
Article
The simulation of transmission electron microscopy (TEM) images or diffraction patterns is often required to interpret their contrast and extract specimen features. This is especially true for high-resolution phase-contrast imaging of materials, but electron scattering simulations based on atomistic models are widely used in materials science and s...
Chapter
Full-text available
The chemical composition of graphene samples and their dopants, functional groups, and impurities is vital information not only for applications but also for many fundamental studies. Other characterization methods mainly based on core-level techniques including X-ray and electron spectroscopies are the most appropriate tools for determining these...
Preprint
Full-text available
Transmission electron microscopy (TEM) and scanning TEM (STEM) are indispensable tools for materials characterization. However, during a typical (S)TEM experiment, the sample is subject to a number of effects that can change its atomic structure. Of these, perhaps the least discussed are chemical modifications due to the non-ideal vacuum around the...
Preprint
Full-text available
Van der Waals materials composed of stacks of individual atomic layers have attracted considerable attention due to their exotic electronic properties that can be altered by, for example, manipulating the twist angle of bilayer materials or the stacking sequence of trilayer materials. To fully understand and control the unique properties of these f...
Preprint
The simulation of transmission electron microscopy (TEM) images or diffraction patterns is often required to interpret their contrast and extract specimen features. This is especially true for high-resolution phase-contrast imaging of materials, but model-based reconstructions in TEM are widely used across the physical and biological sciences. Sinc...
Preprint
Single atoms and few-atom nanoclusters are of high interest in catalysis and plasmonics, but pathways for their fabrication and stable placement remain scarce. We report here the self-assembly of room-temperature-stable single indium (In) atoms and few-atom In clusters (2-6 atoms) that are anchored to substitutional silicon (Si) impurity atoms in s...
Article
Atomistic Understanding of Damage and Beam-Driven Dynamics in 2D Materials - Alexandru Chirita, Alexander Markevich, Jani Kotakoski, Toma Susi
Article
Uncovering the Mechanism for Electron-Beam Manipulation of Dopants in Silicon - Alexander Markevich, Bethany Hudak, Andrew Lupini, Toma Susi
Article
abTEM: ab Initio Transmission Electron Microscopy Image Simulation - Jacob Madsen, Toma Susi
Article
Quantitative Measurement and Utilization of Electron Irradiation Effects in 2D Materials - Gregor Leuthner, Thuy An Bui, Georg Zagler, Bernhard Fickl, Mohammad Monazam, Alexandru Chirita, Toma Susi, Jani Kotakoski
Article
The electronic and magnetic properties of graphene can be modulated by doping it with other elements, especially those with a different number of valence electrons. In this article, we first provide a three-dimensional reconstruction of the atomic structure of a phosphorus substitution in graphene by using aberration-corrected scanning transmission...
Preprint
Full-text available
The Community of Open Scholarship Grassroots Networks (COSGN), includes 120 grassroots networks, representing virtually every region of the world and every research discipline. These networks communicate and coordinate on topics of common interest. We propose, using an NSF 19-501 Full-Scale implementation grant, to formalize governance and coordina...
Article
Full-text available
Synopsis We have investigated theoretically the possibility to diffract hydrogen atoms through a suspended graphene single layer. Using quantum and semi classical approaches we evaluate the momentum and energy exchange to the electronic and vibrational system and estimate their influence on the coherence and spot size.
Article
Full-text available
The recent discovery that impurity atoms in crystals can be manipulated with focused electron irradiation has opened novel perspectives for top‐down atomic engineering. These achievements have been enabled by advances not only in electron optics and microscope stability but also in the preparation of suitable materials with impurity elements incorp...
Preprint
Full-text available
Important recent advances in transmission electron microscopy instrumentation and capabilities have made it indispensable for atomic-scale materials characterization. At the same time, the availability of two-dimensional materials has provided ideal samples where each atom or vacancy can be resolved. Recent studies have also revealed new possibilit...
Article
Full-text available
Pertinent existing hydrogen technologies for energy storage require unsustainable amounts of scarce platinum group metals. Here, an electrocatalyst comprising high-aspect-ratio platinum nanowires (PtNWs) on single-walled carbon nanotubes (SWNTs) with ultralow Pt content (340 ngPt cm⁻²) is employed for hydrogen evolution reaction (HER). A comparable...
Article
Full-text available
Along with hydrogen, carbon, nitrogen and oxygen are the arguably most important elements for organic chemistry. Due to their rich variety of possible bonding configurations, they can form a staggering number of compounds. Here, we present a detailed analysis of nitrogen and oxygen bonding configurations in a defective carbon (graphene) lattice. Us...
Article
Full-text available
The established application of graphene in organic/inorganic spin‐valve spintronic assemblies is as a spin‐transport channel for spin‐polarized electrons injected from ferromagnetic substrates. To generate and control spin injection without such substrates, the graphene backbone must be imprinted with spin‐polarized states and itinerant‐like spins....
Article
Full-text available
The atomic structure of nanomaterials is often studied using transmission electron microscopy. In addition to image formation, the energetic electrons impinging on the sample may also cause damage. In a good conductor such as graphene, the damage is limited to the knock-on process caused by elastic electron-nucleus scattering. This process is deter...
Article
Automated Real-time Analysis of Atomic-resolution STEM Images - Volume 25 Supplement - Jacob Madsen, Andreas Postl, Toma Susi
Article
Full-text available
Substitutional Si Doping of Graphene and Nanotubes through Ion Irradiation-Induced Vacancies - Volume 25 Supplement - Heena Inani, Kimmo Mustonen, Alexander Markevich, Er-Xiong Ding, Mukesh Tripathi, Aqeel Hussian, Clemens Mangler, Esko I. Kauppinen, Toma Susi, Jani Kotakoski
Article
Full-text available
Electron-Beam Manipulation of Lattice Impurities in Graphene and Single-Walled Carbon Nanotubes - Volume 25 Supplement - Toma Susi, Mukesh Tripathi, Kimmo Mustonen, Alexander Markevich, Clemens Mangler, Cong Su, Ju Li, Juan Carlos Idrobo, Jannik Meyer, Jani Kotakoski
Article
Atomic-scale Chemical Manipulation of Materials in the Scanning Transmission Electron Microscope under Controlled Atmospheres - Volume 25 Supplement - Gregor T Leuthner, Clemens Mangler, Jannik C Meyer, Toma Susi, Jani Kotakoski
Article
Quantifying Elastic and Inelastic Electron Irradiation Damage in Transmission Electron Microscopy of 2D Materials - Volume 25 Supplement - Toma Susi, Tibor Lehnert, Ute Kaiser, Jannik Meyer, Jani Kotakoski