Unveiling the nature of atomic defects in graphene on a metal surface

• Karl Rothe,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2024, 15, 416–425, doi:10.3762/bjnano.15.37

• smallest defects appear as a depression without discernible interior structure suggesting the presence of vacancy sites in the graphene lattice. With an atomic force microscope, however, only one kind can be identified as a vacancy defect with four missing carbon atoms, while the other kind reveals an

• intact graphene sheet. Spatially resolved spectroscopy of the differential conductance and the measurement of total-force variations as a function of the lateral and vertical probe–defect distance corroborate the different character of the defects. The tendency of the vacancy defect to form a chemical

• bond with the microscope probe is reflected by the strongest attraction at the vacancy center as well as by hysteresis effects in force traces recorded for tip approach to and retraction from the Pauli repulsion range of vertical distances. Keywords: atomic force microscopy and spectroscopy; graphene

Investigating ripple pattern formation and damage profiles in Si and Ge induced by 100 keV Ar⁺ ion beam: a comparative study

• Indra Sulania,
• Harpreet Sondhi,
• Tanuj Kumar,
• Sunil Ojha,
• G R Umapathy,
• Ambuj Mishra,
• Ambuj Tripathi,
• Richa Krishna,
• Devesh Kumar Avasthi and
• Yogendra Kumar Mishra

Beilstein J. Nanotechnol. 2024, 15, 367–375, doi:10.3762/bjnano.15.33

• subsequently transfers its energy to the atoms of the target material in all the collisions and finally stops. When this energy transfer is sufficient, a displacement of atoms from their equilibrium positions creating a vacancy or a recoil occurs. Alternatively, if the ion energy is high enough such recoils

Controllable physicochemical properties of WO_x thin films grown under glancing angle

• Rupam Mandal,
• Aparajita Mandal,
• Alapan Dutta,
• Rengasamy Sivakumar,
• Sanjeev Kumar Srivastava and
• Tapobrata Som

Beilstein J. Nanotechnol. 2024, 15, 350–359, doi:10.3762/bjnano.15.31

• structural, optical, and electrical properties of glancing angle-deposited NS-WOx thin films, where NS-WOx films of different thicknesses (6–60 nm) are prepared by rf sputtering and exposed to post-growth annealing at 673 K in vacuum (2 × 10−7 mbar). The role of increased oxygen vacancy concentration (OV) on

• concentration within a metal oxide film is known to influence its bandgap and work function values. As OV increases, there is a corresponding rise in electron concentration within the bandgap region, which results in the formation of certain localized electronic states associated with these vacancy defects

Isolation of cubic Si₃P₄ in the form of nanocrystals

• Polina K. Nikiforova,
• Sergei S. Bubenov,
• Vadim B. Platonov,
• Andrey S. Kumskov,
• Nikolay N. Kononov,
• Tatyana A. Kuznetsova and
• Sergey G. Dorofeev

Beilstein J. Nanotechnol. 2023, 14, 971–979, doi:10.3762/bjnano.14.80

• credited to a significant contribution of van der Waals interactions in the studied structure (The P–P distance in the vacancy was 3.22 Å, which is lower than the doubled van der Waals radius of phosphorus [35]). Slight shifts of frequencies are not uncommon for DFT calculations in such cases even when

• XRD evidence that SiP NPs are formed when phosphorus is present in less than an equimolar quantity with respect to hydrogenated silicon. As cubic SiP and Si3P4 are very similar in structure, they are quite likely to be miscible at the nanoscale resulting in a “vacancy doping” scenario with possible

Ultralow-energy amorphization of contaminated silicon samples investigated by molecular dynamics

• Grégoire R. N. Defoort-Levkov,
• Alan Bahm and
• Patrick Philipp

Beilstein J. Nanotechnol. 2023, 14, 834–849, doi:10.3762/bjnano.14.68

• . The 500 subsequent bombardments with their collision cascades lead to the displacement of target atoms, creating disorder and point defects. Hydrogen and oxygen atoms get mixed into the target and can get trapped at interstitial or vacancy sites. The different kind of defects are not intrinsically

Transferability of interatomic potentials for silicene

• Marcin Maździarz

Beilstein J. Nanotechnol. 2023, 14, 574–585, doi:10.3762/bjnano.14.48

• the SO(3) smooth power spectrum potential (SO(3)) fitted to the ground-state of the crystalline silicon structure, strained structures, slabs, vacancy, and liquid configurations from DFT simulations ACE [45]: the machine-learning-based (ML-IAP) variant of the atomic cluster expansion potential (ACE

Plasmonic nanotechnology for photothermal applications – an evaluation

• A. R. Indhu,
• L. Keerthana and
• Gnanaprakash Dharmalingam

Beilstein J. Nanotechnol. 2023, 14, 380–419, doi:10.3762/bjnano.14.33

• curvature [35]. Finally, changes to the material composition, such as through doping or vacancy processing, can affect the LSPR because of changes in the free electron density, the electron effective mass, and the electronic band structure in general [36][37]. An understanding of the changes in absorbance

Recent trends in Bi-based nanomaterials: challenges, fabrication, enhancement techniques, and environmental applications

• Vishal Dutta,
• Ankush Chauhan,
• Ritesh Verma,
• C. Gopalkrishnan and
• Van-Huy Nguyen

Beilstein J. Nanotechnol. 2022, 13, 1316–1336, doi:10.3762/bjnano.13.109

• approach for the in situ synthesis of a series of oxygen-vacancy (OV)-rich Bi0/Bi-based photocatalysts [80]. A new understanding of how Bi0 nanoparticles and OVs are created in situ in Bi-based photocatalysts has been reported. Compared to other Bi-based photocatalysts, Bi0/OV–(BiO)2CO3 showed high

• for separating photogenerated electrons and holes. As a result of the Fe doping, an impurity energy level was produced close to the VB, and an imperfection (oxygen vacancy) energy level was produced close to the CB. Both of these energy levels are in a position to potentially accept photoinduced holes

Theoretical investigations of oxygen vacancy effects in nickel-doped zirconia from ab initio XANES spectroscopy at the oxygen K-edge

• Dick Hartmann Douma,
• Lodvert Tchibota Poaty,
• Alessio Lamperti,
• Stéphane Kenmoe,
• Abdulrafiu Tunde Raji,
• Alberto Debernardi and
• Bernard M’Passi-Mabiala

Beilstein J. Nanotechnol. 2022, 13, 975–985, doi:10.3762/bjnano.13.85

• hybridized with unoccupied Ni 3d states. The intensity of this pre-edge peak, however, reduces upon the introduction of a single vacancy in the 2Ni-doped zirconia matrix. The corresponding ground state remains ferromagnetic, while one of the nickel atoms adopts a trigonal bipyramidal geometry, and the other

• spectrum shows a further decrease in the intensity of the pre-edge peak, compared to the case of a single vacancy. Thus, the changes in the intensity of the pre-edge peak evidence a major structural change in the local environment around nickel atoms and, by extension, in the zirconia matrix. This change

• and magnetic order in a typical diluted magnetic oxide. Such a finding may be crucial for spintronics-related applications. Keywords: defect; ligand field; nickel; oxidation state; oxides; spectroscopy; spintronics; vacancy; X-ray absorption; X-ray absorption near-edge structure (XANES); zirconia

Sodium doping in brookite TiO₂ enhances its photocatalytic activity

• Boxiang Zhuang,
• Honglong Shi,
• Honglei Zhang and
• Zeqian Zhang

Beilstein J. Nanotechnol. 2022, 13, 599–609, doi:10.3762/bjnano.13.52

• confined within the range of 1–3 nm; here, we call it the nanodomain. One nanodomain can develop into the neighboring domain by lattice distortion (Supporting Information File 1, Figure S4a1), interstitial atom, and atomic vacancy (Supporting Information File 1, Figure S4a2). However, these microstructures

Tin dioxide nanomaterial-based photocatalysts for nitrogen oxide oxidation: a review

• Viet Van Pham,
• Hong-Huy Tran,
• Thao Kim Truong and
• Thi Minh Cao

Beilstein J. Nanotechnol. 2022, 13, 96–113, doi:10.3762/bjnano.13.7

• vacancy defects (OVs) [15][16]. Therefore, SnO2 is considered a potential material in various technological fields such as catalysis, optoelectronic devices, rechargeable lithium batteries, electrocatalysis, photocatalysis, solar energy conversion, and gas sensing [17][18][19][20][21][22][23][24]. In the

• band structure, which remains critical for studying charge separation [29]. In another study, a SnO2–Zn2SnO4 Z-scheme photocatalyst system was prepared with a graphene modification to create surface vacancy sites in the composite, which contributed to an enhanced photoactivity in the oxidation of NO

• . Katsiev; J. M. Burst; U. Diebold; A. M. Chaka; B. Delley, Phys. Rev. B, vol. 72, article no. 165414, 2005). Copyright (2005) by the American Physical Society. This content is not subject to CC BY 4.0; (b) SnO2(110) surface including a bridging oxygen vacancy (1-bridging oxygen; 2-bridging OV; 3-oxygen

Measurement of polarization effects in dual-phase ceria-based oxygen permeation membranes using Kelvin probe force microscopy

• Kerstin Neuhaus,
• Christina Schmidt,
• Liudmila Fischer,
• Wilhelm Albert Meulenberg,
• Ke Ran,
• Joachim Mayer and
• Stefan Baumann

Beilstein J. Nanotechnol. 2021, 12, 1380–1391, doi:10.3762/bjnano.12.102

• electrons are trapped at oxygen vacancy sites, allowing also for singly charged () or uncharged (VO) oxygen vacancies in close vicinity to Ce3+ ions [31][32], which show a strongly lowered mobility. For low temperatures, the common electroneutrality equation for acceptor-doped ceria can be shortened, as

Impact of electron–phonon coupling on electron transport through T-shaped arrangements of quantum dots in the Kondo regime

• Patryk Florków and
• Stanisław Lipiński

Beilstein J. Nanotechnol. 2021, 12, 1209–1225, doi:10.3762/bjnano.12.89

• occupation n = 2, two with double occupancy on the single dot and a vacancy on the other dot {(0,2), (2,0)} and four states with single occupancy on each of the dots {(↑,↑), (↑,↓), (↓,↓), (↓,↓)}. For the discussed case of these first states are energetically lower by than the latter. It is well known that

Is the Ne operation of the helium ion microscope suitable for electron backscatter diffraction sample preparation?

• Annalena Wolff

Beilstein J. Nanotechnol. 2021, 12, 965–983, doi:10.3762/bjnano.12.73

• displacements, replacement collisions, vacancy formation, and a collision cascade as well as backscattered ions, secondary ion emission, and ion implantation. A more detailed description of ion–solid interactions can be found in [20][21]. The difference between different ion species, energies, and incident

• determine the resulting interaction volume of the ions for the various conditions as well as vacancy formation and implanted impurity concentration. In addition, the achieved results are compared to those achieved by the conventionally used argon ion polishing (PIPS) and electropolishing approaches. Results

Prediction of Co and Ru nanocluster morphology on 2D MoS₂ from interaction energies

• Cara-Lena Nies and
• Michael Nolan

Beilstein J. Nanotechnol. 2021, 12, 704–724, doi:10.3762/bjnano.12.56

• stability of metal clusters on MoS2, and how these interactions change in the presence of a sulfur vacancy, to develop insight to allow for a prediction of thin film morphology. The strength of interaction between the metals and MoS2 is in the order Co > Ru. The competition between metal–substrate and metal

• –metal interaction allows us to conclude that 2D structures should be preferred for Co on MoS2, while Ru prefers 3D structures on MoS2. However, the presence of a sulfur vacancy decreases the metal–metal interaction, indicating that with controlled surface modification 2D Ru structures could be achieved

• (Supporting Information File 1, section S4) show that vdW forces do not dominate in these types of structures. The defective ML has the same structure as the pristine ML, except that a single S atom has been removed to create a vacancy and the ions are relaxed with no symmetry constraints. Using H2S as a

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

• Frances I. Allen

Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52

• through site-selective irradiation, rather than through chemical functionalization of its surface. Nakaharai et al. irradiated supported single-layer graphene with 30 keV helium ions increasing the dose from ca. 2 × 1015 to 1 × 1016 ions/cm2 (corresponding to an estimated vacancy defect concentration of

• introduction of lattice vacancy defects, and with an increase in the average interatomic distances due to swelling, that is, a magnetovolume effect. And in a recent report implementing in situ current–voltage characterization, site-selective helium ion irradiation of cobalt-based magnetic multilayer structures

• increasing dose the ferroelectric domains were gradually destroyed [57]. Optical properties In early work concerned with tuning optical properties with the HIM, arrays of nitrogen-vacancy centers were fabricated in diamond [58][59]. Starting with a diamond sample that already contained substitutional

Impact of GaAs(100) surface preparation on EQE of AZO/Al₂O₃/p-GaAs photovoltaic structures

• Piotr Caban,
• Rafał Pietruszka,
• Jarosław Kaszewski,
• Monika Ożga,
• Bartłomiej S. Witkowski,
• Krzysztof Kopalko,
• Piotr Kuźmiuk,
• Katarzyna Gwóźdź,
• Ewa Płaczek-Popko,
• Krystyna Lawniczak-Jablonska and
• Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 578–592, doi:10.3762/bjnano.12.48

• ]). The intensities of the defect bands in relation to each other and to the NBE band are associated with the route of AZO growth. The point defects usually observed in ZnO are: oxygen vacancy VO, zinc vacancy VZn, interstitial oxygen Oi, interstitial zinc Zni, and oxygen antisite OZn [44][45]. The

Properties of graphene deposited on GaN nanowires: influence of nanowire roughness, self-induced nanogating and defects

• Jakub Kierdaszuk,
• Piotr Kaźmierczak,
• Justyna Grzonka,
• Aleksandra Krajewska,
• Aleksandra Przewłoka,
• Wawrzyniec Kaszub,
• Zbigniew R. Zytkiewicz,
• Marta Sobanska,
• Maria Kamińska,
• Andrzej Wysmołek and
• Aneta Drabińska

Beilstein J. Nanotechnol. 2021, 12, 566–577, doi:10.3762/bjnano.12.47

• main defects in the N500 sample (maximum of distribution at RDD’ is equal to 4.1). At least 98% of all types of defects in the N500 sample are grain boundaries, which is a higher value than the obtained for vacancy contribution in N0 and N100 samples (88% and 79%, respectively). The standard deviation

Bio-imaging with the helium-ion microscope: A review

• Matthias Schmidt,
• James M. Byrne and
• Ilari J. Maasilta

Beilstein J. Nanotechnol. 2021, 12, 1–23, doi:10.3762/bjnano.12.1

• doped with the fluorescent nitrogen-vacancy defect as well as rare earth metal-based nanoparticles regarding bleaching under the ion beam. Although they are believed to be photostable under electron irradiation, the IL of the nanoscale diamonds decreased significantly under the ion beam even at doses

Oxidation of Au/Ag films by oxygen plasma: phase separation and generation of nanoporosity

• Abdel-Aziz El Mel,
• Said A. Mansour,
• Mujaheed Pasha,
• Atef Zekri,
• Janarthanan Ponraj,
• Akshath Shetty and
• Yousef Haik

Beilstein J. Nanotechnol. 2020, 11, 1608–1614, doi:10.3762/bjnano.11.143

• , supersaturated vacancy clouds form within the metal alloy film. In order to minimize the energy of the system these vacancies tend to condensate and to form voids, which develop into nanopores in a later oxidation stage. The vacancy injection process continues until silver is completely extracted from the film

Wafer-level integration of self-aligned high aspect ratio silicon 3D structures using the MACE method with Au, Pd, Pt, Cu, and Ir

• Mathias Franz,
• Romy Junghans,
• Paul Schmitt,
• Adriana Szeghalmi and
• Stefan E. Schulz

Beilstein J. Nanotechnol. 2020, 11, 1439–1449, doi:10.3762/bjnano.11.128

• comparably as catalyst [23]. Chartier et al. [13] reported the etching mechanisms of the MACE process. The cathodic reaction is the reduction of H2O2 at the noble metal interface within an acidic solution. This reduction transfers an electron to the H+ ion and produces a hole (an electron vacancy) h+: The

Atomic defect classification of the H–Si(100) surface through multi-mode scanning probe microscopy

• Jeremiah Croshaw,
• Thomas Dienel,
• Taleana Huff and
• Robert Wolkow

Beilstein J. Nanotechnol. 2020, 11, 1346–1360, doi:10.3762/bjnano.11.119

• (DB) of a surface Si atom (Figure 2a), a subsurface vacancy (Figure 2b), a SiH3 group (Figure 2i), and an unidentified surface point defect (Figure 2k). Second, defects affecting a whole dimer which include two missing H atoms creating a bare dimer (neutral, shown in [50][51]), two additional H atoms

• using the probe particle model [23][24] and is discussed in the Supporting Information File 1, with Figures S5, S6, and S7. Figure 2b shows a suspected silicon vacancy (discussed in more detail below in Figure 4), previously referred to as a type 2 (T2) defect in the literature [58]. Prior works

• speculated a variety of origins for this defect, including a negatively charged As dopant [58], Si-vacancy hydrogen complexes [9], and B dopants [59][60]. Crystal vacancies have previously been identified in other materials using scanning probe microscopy including Ga vacancies in GaAs [61], As vacancies in

Effect of localized helium ion irradiation on the performance of synthetic monolayer MoS₂ field-effect transistors

• Jakub Jadwiszczak,
• Pierce Maguire,
• Conor P. Cullen,
• Georg S. Duesberg and
• Hongzhou Zhang

Beilstein J. Nanotechnol. 2020, 11, 1329–1335, doi:10.3762/bjnano.11.117

• than half of the channel has been treated with the ion beam. Thus, we expect a dominant contribution of oxygen-containing atmospheric adsorbates (known p-type dopants in MoS2) in saturating the vacancy sites created by the ion beam, allowing for residual hole conduction in the newly formed effective

• atomic vacancy yield per each delivered ion as a function of target penetration depth on the 35 nm-Au/5 nm-Ti/0.7 nm-MoS2/285 nm-SiO2 stack [41]. As evident from Figure 3d, the sulfur sputtering yield at the Ti–MoS2 interface is very close to that of unencapsulated MoS2 [15], indicating notable damage to

• ) Simulation of the S vacancy yield generated as the He+ ion beam penetrates the device at the contact stack, indicating damage to the metal–semiconductor interface. Acknowledgements We acknowledge D. Keane for helpful discussions and D. Daly for assistance with the helium ion microscope. Funding The

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

• spin–photon interfaces for remote spin–photon entanglement with available nuclear spins as ancilla qubits for quantum memory [11][12]. These include the nitrogen-vacancy (NV) center in diamond [13], the silicon-vacancy center in diamond [14][15][16], the germanium-vacancy center in diamond [17], the

• divacancy (DV) in silicon carbide (SiC) [18][19][20], the silicon monovacancy in SiC [21][22][23], the carbon antisite vacancy pair in SiC [24][25], the silicon vacancy and nitrogen (N) atom on an adjacent carbon site in SiC [26][27][28], and rare-earth impurities in complex oxides [29]. While the NV center

• /compatibility of the active quantum source and the device in use, and they have limitations in terms of scalability. The type of point defects that should be addressed is also a key element and is generally substitutional dopants, native vacancies, and dopant-vacancy complexes. The space of possible defects is

Atomic-resolution imaging of rutile TiO₂(110)-(1 × 2) reconstructed surface by non-contact atomic force microscopy

• Daiki Katsube,
• Shoki Ojima,
• Eiichi Inami and
• Masayuki Abe

Beilstein J. Nanotechnol. 2020, 11, 443–449, doi:10.3762/bjnano.11.35

• -AFM and tunneling current for STM), the surface structure sometimes results in different contrasts in both images. In Figure 3, white squares and circles indicate line defects and protrusions, which are considered to be adsorbates or contamination. A line defect was imaged as a likely vacancy by STM