Effect of substitutional defects on resonant tunneling diodes based on armchair graphene and boron nitride nanoribbons lateral heterojunctions

• Majid Sanaeepur

Beilstein J. Nanotechnol. 2020, 11, 688–694, doi:10.3762/bjnano.11.56

• between graphene and hBN [3]. However, inevitable interfacial defects located at the interface of Gr/hBN heterojunctions, including point defects (single vacancies and substitutional defects) and topological defects can alter the electronic properties of Gr/hBN heterostructures and, consequently, the

Precise local control of liquid crystal pretilt on polymer layers by focused ion beam nanopatterning

• Maxim V. Gorkunov,
• Irina V. Kasyanova,
• Vladimir V. Artemov,
• Alena V. Mamonova and
• Serguei P. Palto

Beilstein J. Nanotechnol. 2019, 10, 1691–1697, doi:10.3762/bjnano.10.164

• example, helps avoiding topological defects [11] and accelerates switching of vertically aligned LC cells [12]. It is quantitatively characterized by the pretilt angle between the director and the surface plane. Surfaces stabilizing pretilted alignments remain rare and require more complex fabrication

Disorder in H⁺-irradiated HOPG: effect of impinging energy and dose on Raman D-band splitting and surface topography

• Lisandro Venosta,
• Noelia Bajales,
• Sergio Suárez and
• Paula G. Bercoff

Beilstein J. Nanotechnol. 2018, 9, 2708–2717, doi:10.3762/bjnano.9.253

• -wavelength excitation [9][15][18]. Since Raman spectroscopy with visible wavelengths does not allow for a distinction of the contribution of structural and topological defects from the contribution of C–H bonds to the D band [21], especially when the H content is lower than 20% [15], the use of complementary

• . Numerous studies have shown that the relative intensity of the D band to the G band, ID/IG, increases with increasing disorder resulting from structural and topological defects as well as H implantation in hydrogenated samples. Tuinstra et al. [8] introduced a method for determining the average crystal

Cyclodextrin-assisted synthesis of tailored mesoporous silica nanoparticles

• Fuat Topuz and
• Tamer Uyar

Beilstein J. Nanotechnol. 2018, 9, 693–703, doi:10.3762/bjnano.9.64

• alkaline solution were previously reported [26]. For the generation of different shapes and faceted morphology of mesoporous silica, Ozin and co-workers reported that the shape of mesoporous silica largely depends on the degree of curvature and the accretion-type induced by various topological defects in

Nematic topological defects positionally controlled by geometry and external fields

• Pavlo Kurioz,
• Marko Kralj,
• Bryce S. Murray,
• Charles Rosenblatt and
• Samo Kralj

Beilstein J. Nanotechnol. 2018, 9, 109–118, doi:10.3762/bjnano.9.13

• and external fields on the spatial positioning of nematic topological defects (TDs). In quasi two-dimensional systems we demonstrate that a confinement-enforced total topological charge of m > 1/2 decays into elementary TDs bearing a charge of m = 1/2. These assemble close to the bounding substrate to

• functional nanodevices. Keywords: nanoparticles; nematic liquid crystals; topological charge; topological defects; Introduction Topological defects (TDs) [1] represent an interdisciplinary research area [2] that is of high interest for nearly all branches of science. Due to their topological origin they

• entities of nature and not fundamental particles [3], which are, in this case, an emergent phenomenon. For example, as far back as 1962, Skyrme [4] developed a theory in which he described hadrons as topological defects in the pion field. A convenient system in which to study the fundamental behavior of

One-step chemical vapor deposition synthesis and supercapacitor performance of nitrogen-doped porous carbon–carbon nanotube hybrids

• Egor V. Lobiak,
• Lyubov G. Bulusheva,
• Ekaterina O. Fedorovskaya,
• Yury V. Shubin,
• Pavel E. Plyusnin,
• Pierre Lonchambon,
• Boris V. Senkovskiy,
• Zinfer R. Ismagilov,
• Emmanuel Flahaut and
• Alexander V. Okotrub

Beilstein J. Nanotechnol. 2017, 8, 2669–2679, doi:10.3762/bjnano.8.267

• has no such obvious dependence (Figure 6b). Based on these data we conclude that the nitrogen defects strongly affect the 2D band, while the D band intensity in the Raman spectra of the materials under study is mainly influenced by topological defects in the porous carbon. The presence of the largest

Photocurrent generation in carbon nanotube/cubic-phase HfO₂ nanoparticle hybrid nanocomposites

• Protima Rauwel,
• Augustinas Galeckas,
• Martin Salumaa,
• Frédérique Ducroquet and
• Erwan Rauwel

Beilstein J. Nanotechnol. 2016, 7, 1075–1085, doi:10.3762/bjnano.7.101

• that according to literature reports, attachment of nanoparticles to the sidewalls of MWCNTs appears to be only possible via functionalization of the sidewalls. In our case, no functionalization has taken place, nor in the image do we observe the presence of curved regions or topological defects that

High I_on/I_off current ratio graphene field effect transistor: the role of line defect

• Mohammad Hadi Tajarrod and
• Hassan Rasooli Saghai

Beilstein J. Nanotechnol. 2015, 6, 2062–2068, doi:10.3762/bjnano.6.210

• presence of one-dimensional topological defects. The defects containing 5–8–5 sp2-hybridized carbon rings were placed in a perfect graphene sheet. The atomic scale behavior of the transistor was investigated in the non-equilibrium Green's function (NEGF) and tight-binding Hamiltonian frameworks. AGNRFET

• transistor devices [5][6]. The electronic properties of graphene are the result of its particular structure. In order to modify the transport behavior, the physical structure of graphene needs to be changed. Consequently, topological defects such as vacancies, impurities, adatoms and Stone–Wales defects are

Applications of three-dimensional carbon nanotube networks

• Manuela Scarselli,
• Paola Castrucci,
• Francesco De Nicola,
• Ilaria Cacciotti,
• Francesca Nanni,
• Emanuela Gatto,
• Mariano Venanzi and
• Maurizio De Crescenzi

Beilstein J. Nanotechnol. 2015, 6, 792–798, doi:10.3762/bjnano.6.82

• , with pore sizes from several nanometers to a few micrometers (Figure 2a). The high number of interconnections indicated by the arrows in Figure 2b is caused by the presence of topological defects in the carbon sp2 lattice that originate during the growth process. In particular, the addition of sulfur

Overview of nanoscale NEXAFS performed with soft X-ray microscopes

• Peter Guttmann and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 595–604, doi:10.3762/bjnano.6.61

• -edge signal at 284.2 eV. Topological defects added additional spectral features in the π and σ region of the absorption edge [2]. STXMs have no optical element between the sample and the detector. Therefore, the radiation dose applied to the sample during the investigation might be lower. This is

Entropy effects in the collective dynamic behavior of alkyl monolayers tethered to Si(111)

• Christian Godet

Beilstein J. Nanotechnol. 2015, 6, 583–594, doi:10.3762/bjnano.6.60

• previous work [40] to large reverse dc bias applied to Hg/C12H25/Si tunnel junctions, resulting in a change in the distribution of topological defects, reveals a collective behavior of linear saturated (n-alkyl) chains tethered to the Si(111) surface. The effects of both temperature and applied dc bias on

Fringe structures and tunable bandgap width of 2D boron nitride nanosheets

• Peter Feng,
• Muhammad Sajjad,
• Eric Yiming Li,
• Hongxin Zhang,
• Jin Chu,
• Ali Aldalbahi and
• Gerardo Morell

Beilstein J. Nanotechnol. 2014, 5, 1186–1192, doi:10.3762/bjnano.5.130

• images is 8 s. Also visible in the sequence is the generation of vacancies within the layer. (c,d) Topological defects are incorporated during this edge reconstruction. On the other edge of the same hole, atoms are removed by the electron beam. Scale bar, 2 nm. (a) Experimental set up for H plasma

Large-scale atomistic and quantum-mechanical simulations of a Nafion membrane: Morphology, proton solvation and charge transport

• Pavel V. Komarov,
• Pavel G. Khalatur and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2013, 4, 567–587, doi:10.3762/bjnano.4.65

• aqueous medium occur very fast, typically within 0.1–0.2 ps. Due to the further solvation, the ion pairs transform into shared proton complexes SO3−·H3O+·(H2O). The Zundel cations are then formed via the proton transfer reaction H3O+ + H2O → H5O2+. At the next step, the topological defects in the hydrogen

X-ray absorption spectroscopy by full-field X-ray microscopy of a thin graphite flake: Imaging and electronic structure via the carbon K-edge

• Carla Bittencourt,
• Adam P. Hitchock,
• Xiaoxing Ke,
• Gustaaf Van Tendeloo,
• Chris P. Ewels and
• Peter Guttmann

Beilstein J. Nanotechnol. 2012, 3, 345–350, doi:10.3762/bjnano.3.39

• presence of topological defects. Doping by metal impurities that were present in the original exfoliated graphite is indicated by the presence of a pre-edge signal at 284.2 eV. Keywords: carbon; graphene; nanostructure; NEXAFS; X-ray microscopy; Introduction The demonstration of the remarkable transport

• energy of this structure, indicating that the doping is rather uniform in the flake. In a recent theoretical study, spectral features appearing at 287–290 eV photon energy were associated with topological defects, such as monovacancies, divacancies and Stone–Wales defects [26]. In particular, a structure