Thermoelectric current in topological insulator nanowires with impurities

• Sigurdur I. Erlingsson,
• Jens H. Bardarson and
• Andrei Manolescu

Beilstein J. Nanotechnol. 2018, 9, 1156–1161, doi:10.3762/bjnano.9.107

• charge current generated by maintaining a temperature difference over a nanowire at zero voltage bias. For topological insulator nanowires in a perpendicular magnetic field the current can change sign as the temperature of one end is increased. Here we study how this thermoelectric current sign reversal

• impurity concentration the sign reversal persists. Keywords: topological insulators, nanowires, thermoelectric current; Introduction It has been known for quite some time now that the efficiency of thermoelectric devices can be increased by reducing the system size. The size reduction can improve

• properties is not always straightforward [3]. Even though few experimental studies exist on thermoelectric properties in topological insulator nanowires (TIN), many studies have reported magnetoresistance oscillations, both in longitudinal and transversal fields for TINs [4][5][6][7][8][9][10]. In its

Field-controlled ultrafast magnetization dynamics in two-dimensional nanoscale ferromagnetic antidot arrays

• Anulekha De,
• Sucheta Mondal,
• Sourav Sahoo,
• Saswati Barman,
• Yoshichika Otani,
• Rajib Kumar Mitra and
• Anjan Barman

Beilstein J. Nanotechnol. 2018, 9, 1123–1134, doi:10.3762/bjnano.9.104

• magnetic metamaterials, known as magnonic crystals (MCs), which have great potential for technological applications and fundamental research [1][2]. Investigation and tailoring of the magnetization dynamics in ferromagnetic nanodots [3][4], nanowires [5] and antidots [6][7][8] have fuelled considerable

Review on nanoparticles and nanostructured materials: history, sources, toxicity and regulations

• Jaison Jeevanandam,
• Ahmed Barhoum,
• Yen S. Chan,
• Alain Dufresne and
• Michael K. Danquah

Beilstein J. Nanotechnol. 2018, 9, 1050–1074, doi:10.3762/bjnano.9.98

• external nanoscale dimension or having internal nanoscale surface structure” [4]. Nanofibers, nanoplates, nanowires, quantum dots and other related terms have been defined based on this ISO definition [5]. Likewise, the term nanomaterial is described as “a manufactured or natural material that possesses

Magnetic characterization of cobalt nanowires and square nanorings fabricated by focused electron beam induced deposition

• Federico Venturi,
• Gian Carlo Gazzadi,
• Amir H. Tavabi,
• Alberto Rota,
• Rafal E. Dunin-Borkowski and
• Stefano Frabboni

Beilstein J. Nanotechnol. 2018, 9, 1040–1049, doi:10.3762/bjnano.9.97

• nanowires (NWs) and square nanorings, which were deposited by focused electron beam induced deposition (FEBID) of a Co carbonyl precursor, are studied using off-axis electron holography (EH), Lorentz transmission electron microscopy (L-TEM) and magnetic force microscopy (MFM). EH shows that NWs deposited

• used was a Veeco MESP probe, which was made from Sb-doped (n) Si covered by CoCr. The tip was magnetized out-of-plane in a 0.32 T field. Results and Discussion Electron holography of nanowires A first magnetic analysis was carried out on the NWs using off-axis electron holography. The measurements were

• ]. Following this argument, the B value measured in our nanowires should be 15% higher than that for vertical nanopillars with the same Co purity. This turns out to be in perfect agreement with our recent work [39], where a B value of 1.1 T was measured for vertical Co nanopillars having the same composition

Single-crystalline FeCo nanoparticle-filled carbon nanotubes: synthesis, structural characterization and magnetic properties

• Rasha Ghunaim,
• Maik Scholz,
• Christine Damm,
• Bernd Rellinghaus,
• Rüdiger Klingeler,
• Bernd Büchner,
• Michael Mertig and
• Silke Hampel

Beilstein J. Nanotechnol. 2018, 9, 1024–1034, doi:10.3762/bjnano.9.95

• ][20], and are thus highly suitable for high-temperature applications. However, reducing the size of these materials down to the nanoscale to produce nanowires and nanoparticles results in a robust enhancement in the coercivity [21][22], which make them good candidates for high-density magnetic storage

Tuning adhesion forces between functionalized gold colloidal nanoparticles and silicon AFM tips: role of ligands and capillary forces

• Sven Oras,
• Sergei Vlassov,
• Marta Berholts,
• Rünno Lõhmus and
• Karine Mougin

Beilstein J. Nanotechnol. 2018, 9, 660–670, doi:10.3762/bjnano.9.61

• accurate control of their intrinsic properties. For instance, Au nanospheres, nanocubes, nanorods and nanowires [10] have been routinely synthesized. Their physico-chemical and especially optical properties [11] of NPs strongly depend on their shape, size and spatial arrangement [12][13][14][15]. All these

Electron interaction with copper(II) carboxylate compounds

• Michal Lacko,
• Peter Papp,
• Iwona B. Szymańska,
• Edward Szłyk and
• Štefan Matejčík

Beilstein J. Nanotechnol. 2018, 9, 384–398, doi:10.3762/bjnano.9.38

• -induced deformation, and electromigration resistance which is higher than for aluminum [24][25][26][27]. Copper nanostructures, especially nanowires, are applied in opto-electronic devices, solar cells, field-emission displays, catalysis, electronic skins, and sensor devices. Moreover, they can find

Review: Electrostatically actuated nanobeam-based nanoelectromechanical switches – materials solutions and operational conditions

• Liga Jasulaneca,
• Jelena Kosmaca,
• Raimonds Meija,
• Jana Andzane and
• Donats Erts

Beilstein J. Nanotechnol. 2018, 9, 271–300, doi:10.3762/bjnano.9.29

• : nanocontacts; nanoelectromechanical switches; nanowires; NEM; reliability; Review Introduction Nanoelectromechanical (NEM) switches represent a class of nanoscale devices, integrating both electrical and mechanical functionality of nanostructures to process external stimuli applied to the device and

• nanostructures (e.g., thin films [5][6][7], nanobundles [8], nanowires [9][10][11][12][13][14], nanotubes [15][16]) fabricated from different materials (e.g., metals [17][18][19], semiconductors [9][10][20][21][22][23], carbon allotropes, including graphene [24][25][26][27][28][29][30][31] and carbon nanotubes

• nanostructures (nanowires, nanotubes, nanorods, graphene) with a good uniformity and desired properties. The microfabrication routine may be supplemented with some bottom-up approaches. Dielectrophoresis [33], controlled nanomaterial growth [34], and nanomanipulation [9] have been demonstrated as useful methods

Synthesis and characterization of electrospun molybdenum dioxide–carbon nanofibers as sulfur matrix additives for rechargeable lithium–sulfur battery applications

• Ruiyuan Zhuang,
• Shanshan Yao,
• Maoxiang Jing,
• Xiangqian Shen,
• Jun Xiang,
• Tianbao Li,
• Kesong Xiao and
• Shibiao Qin

Beilstein J. Nanotechnol. 2018, 9, 262–270, doi:10.3762/bjnano.9.28

• (1D) MoO2–CNFs nanocomposites, especially with secondary MoO2 nanostructures, are difficult to achieve due to lack of appropriate and generalized synthetic methodologies. Recently, hierarchical MoO2/C microspheres and hierarchical MoO2/Mo2C/C hybrid nanowires were fabricated using organic–inorganic

Dopant-stimulated growth of GaN nanotube-like nanostructures on Si(111) by molecular beam epitaxy

• Alexey D. Bolshakov,
• Alexey M. Mozharov,
• Georgiy A. Sapunov,
• Igor V. Shtrom,
• Nickolay V. Sibirev,
• Vladimir V. Fedorov,
• Evgeniy V. Ubyivovk,
• Maria Tchernycheva,
• George E. Cirlin and
• Ivan S. Mukhin

Beilstein J. Nanotechnol. 2018, 9, 146–154, doi:10.3762/bjnano.9.17

• , Institut d’Electronique Fondamentale, UMR 8622 CNRS, University Paris Sud, University Paris-Saclay, 91405 Orsay cedex, France 10.3762/bjnano.9.17 Abstract In this paper we study growth of quasi-one-dimensional GaN nanowires (NWs) and nanotube (NT)-like nanostructures on Si(111) substrates covered with a

• concentration in the nanostructures exceeds 5∙1019 cm−3. Keywords: A3B5 on Si; epitaxy; GaN; MBE; nanowires; nanotubes; nanotube-like nanostructures; Si; Introduction Gallium nitride quasi-one-dimensional nanostructures such as nanowires (NWs) and nanotubes (NTs) synthesized by means of plasma-assisted

• defect-free structures on highly mismatched substrates, e.g., GaN NWs on Si [7][8]. NWs usually possess high crystal quality due to the effective mechanical stress relaxation at a distance of about one NW base diameter from the substrate. Nanowires synthesized on Si are very promising nanostructures in

Combined scanning probe electronic and thermal characterization of an indium arsenide nanowire

• Tino Wagner,
• Fabian Menges,
• Heike Riel,
• Bernd Gotsmann and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2018, 9, 129–136, doi:10.3762/bjnano.9.15

• S3), confirming the reduction of long-range effects due to detection of the force gradient. Being sensitive to the electrostatic force instead, AM-KFM measurements of similar nanowires [4][28][29][30] have previously shown pronounced lateral averaging, reducing both accuracy and resolution of the

• temperature beneath them inaccessible to SThM.) The thermal conductivity of the InAs nanowire, κ = (3.0 ± 1.4) W·m−1·K−1, is in good agreement with measurements of similar InAs nanowires in microelectromechanical heater/sensor setups [31][32], or with measurements of a 40 nm thick InAs nanofilm [33]. Note

• that stacking faults perpendicular to the growth direction limit the thermal conductivity of our nanowire [31][34], compared to higher-quality crystalline InAs nanowires [35]. We calculate the interfacial thermal conductivity to the substrate and electrodes along the perimeter of the nanowire from the

Comparative study of post-growth annealing of Cu(hfac)₂, Co₂(CO)₈ and Me₂Au(acac) metal precursors deposited by FEBID

• Marcos V. Puydinger dos Santos,
• Aleksandra Szkudlarek,
• Artur Rydosz,
• Carlos Guerra-Nuñez,
• Fanny Béron,
• Kleber R. Pirota,
• Stanislav Moshkalev,
• José Alexandre Diniz and
• Ivo Utke

Beilstein J. Nanotechnol. 2018, 9, 91–101, doi:10.3762/bjnano.9.11

• ], ferromagnetic nanostructures for magnetic logic and memory [23][24][25], as well as functional core–shell ferromagnetic nanowires with improved magnetic properties [26] have already been realised through this technique. It is worth mentioning that the superior conductivity of Cu, compared to other non-noble

Gas-sensing behaviour of ZnO/diamond nanostructures

• Marina Davydova,
• Alexandr Laposa,
• Jiri Smarhak,
• Alexander Kromka,
• Neda Neykova,
• Josef Nahlik,
• Jiri Kroutil,
• Jan Drahokoupil and
• Jan Voves

Beilstein J. Nanotechnol. 2018, 9, 22–29, doi:10.3762/bjnano.9.4

• ]. Sadek et al. fabricated a ZnO nanobelt sensor and tested it for NO2 gas at operating temperatures between 150 and 450 °C. The optimum operating temperature for NO2 detection was in the range between 300 °C and 350 °C [25]. The sensing properties of various ZnO nanostructures (ZnO nanowires and ZnO–SnO2

• core–shell nanowires) were investigated by Hwang and co-workers. The gas response of ZnO–SnO2 core–shell nanowires to 10 ppm NO2 at 200 °C and 300 °C were 66.3 and 12.4, respectively, which is ca. 33- and ca. 8.9-times higher than the respective values of 2.0 and 1.4 for ZnO nanowires [26]. Presently

The rational design of a Au(I) precursor for focused electron beam induced deposition

• Ali Marashdeh,
• Thiadrik Tiesma,
• Niels J. C. van Velzen,
• Sjoerd Harder,
• Remco W. A. Havenith,
• Jeff T. M. De Hosson and
• Willem F. van Dorp

Beilstein J. Nanotechnol. 2017, 8, 2753–2765, doi:10.3762/bjnano.8.274

• contacting of nanowires [21]. Furthermore, as electron beams can be focused to sub-nanometer-sized spots, the reactions can be limited to very small areas. Features as small as 0.6 nm have been written using FEBIP [22] and the deposition can be followed molecule by molecule [23]. One of the main challenges

CdSe nanorod/TiO₂ nanoparticle heterojunctions with enhanced solar- and visible-light photocatalytic activity

• Fakher Laatar,
• Hatem Moussa,
• Halima Alem,
• Lavinia Balan,
• Emilien Girot,
• Ghouti Medjahdi,
• Hatem Ezzaouia and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2017, 8, 2741–2752, doi:10.3762/bjnano.8.273

• nanoparticles (Aeroxide® P25) are of spherical/ellipsoidal shape and their average diameter is ≈23 ± 6 nm (Figure 1a). CdSe NRs produced after the solvothermal synthesis have an average length and an average diameter of 120 and 12 nm, respectively (Figure 1b). Some nanowires with lengths up to 300 nm could also

Beyond Moore’s technologies: operation principles of a superconductor alternative

• Igor I. Soloviev,
• Nikolay V. Klenov,
• Sergey V. Bakurskiy,
• Mikhail Yu. Kupriyanov,
• Alexander L. Gudkov and
• Anatoli S. Sidorenko

Beilstein J. Nanotechnol. 2017, 8, 2689–2710, doi:10.3762/bjnano.8.269

The role of ligands in coinage-metal nanoparticles for electronics

• Ioannis Kanelidis and
• Tobias Kraus

Beilstein J. Nanotechnol. 2017, 8, 2625–2639, doi:10.3762/bjnano.8.263

• rings [48], or patterned grids [49] have been fabricated as transparent conductive electrodes. Inks of metal nanoparticles are also good candidates to print electrodes for organic field-effect transistors [50]. Magdassi et al. demonstrated the inkject printing of silver nanowires (Ag NWs) onto plastic

• initial nucleation processes of particle synthesis; this is probably the mechanism of the formation of ultrathin gold nanowires [64]. Silver nanoparticle synthesis by reduction of silver salts is an important case of ligand-directed nanoparticle growth. Cetyltrimethylammonium bromide (CTAB, Figure 2) in

• silver nitrate in the presence of poly(vinylpyrrolidone) (PVP, Figure 2) and sodium bromide. The nanobars formed when bromide ions etched the multiply twinned seeds, promoted the formation of single crystal seeds, and initiated anisotropic growth [68]. Longer silver nanowires grew from multiply twinned

Localized growth of carbon nanotubes via lithographic fabrication of metallic deposits

• Fan Tu,
• Martin Drost,
• Imre Szenti,
• Janos Kiss,
• Zoltan Kónya and
• Hubertus Marbach

Beilstein J. Nanotechnol. 2017, 8, 2592–2605, doi:10.3762/bjnano.8.260

• for further improvements in the fabrication process. If one also considers the exploration of other precursors for both processes and surfaces, even more possibilities to tailor secondary nanostructures can be considered, including Si or Ge nanowires. One more specific direction might be to target the

Direct writing of gold nanostructures with an electron beam: On the way to pure nanostructures by combining optimized deposition with oxygen-plasma treatment

• Domagoj Belić,
• Mostafa M. Shawrav,
• Emmerich Bertagnolli and
• Heinz D. Wanzenboeck

Beilstein J. Nanotechnol. 2017, 8, 2530–2543, doi:10.3762/bjnano.8.253

• years several methods to purify FEBID deposits have been presented. For instance, in the case of tungsten, it was found that just by applying a smart writing strategy one could produce single-crystal nanowires [47] whereas the use of a supersonic carrier gas can also yield nanostructures of a high

• the spacing between {1,1,1}, {2,0,0}, {2,2,0}, and {3,1,1} planes in the face centered cubic (fcc) Au lattice, respectively. Apart from the deposition of NPs, we used FEBID to directly write horizontal Au nanowires (NWs), NW networks, and planar structures (Figure 1d,e). In the latter case, the

Au nanostructure fabrication by pulsed laser deposition in open air: Influence of the deposition geometry

• Rumen G. Nikov,
• Anna Og. Dikovska,
• Nikolay N. Nedyalkov,
• Georgi V. Avdeev and
• Petar A. Atanasov

Beilstein J. Nanotechnol. 2017, 8, 2438–2445, doi:10.3762/bjnano.8.242

• decrease in the target–substrate distance below 3 mm resulted in the formation of denser, larger structures compared to deposition at larger distances [23]. In the latter case, micrometer-sized droplets and fine nanowires around and over them were obtained [21][23]. Despite the recent significant progress

Hydrothermal synthesis of ZnO quantum dot/KNb₃O₈ nanosheet photocatalysts for reducing carbon dioxide to methanol

• Xiao Shao,
• Weiyue Xin and
• Xiaohong Yin

Beilstein J. Nanotechnol. 2017, 8, 2264–2270, doi:10.3762/bjnano.8.226

• concentration of Nb2O5 was favorable to form NaNbO3 nanorods and nanoplates, while a lower concentration of NaOH facilitated formation of NaNbO3 cubes [12]. Shi and his co-workers synthesized polymeric g-C3N4 coupled with NaNbO3 nanowires for enhancing photocatalytic reduction of CO2 into renewable fuel [13

Substrate and Mg doping effects in GaAs nanowires

• Perumal Kannappan,
• Nabiha Ben Sedrine,
• Jennifer P. Teixeira,
• Maria R. Soares,
• Bruno P. Falcão,
• Maria R. Correia,
• Nestor Cifuentes,
• Emilson R. Viana,
• Marcus V. B. Moreira,
• Geraldo M. Ribeiro,
• Alfredo G. de Oliveira,
• Juan C. González and
• Joaquim P. Leitão

Beilstein J. Nanotechnol. 2017, 8, 2126–2138, doi:10.3762/bjnano.8.212

• Abstract Mg doping of GaAs nanowires has been established as a viable alternative to Be doping in order to achieve p-type electrical conductivity. Although reports on the optical properties are available, few reports exist about the physical properties of intermediate-to-high Mg doping in GaAs nanowires

• the GaAs nanowires on their electronic structure; ii) a considerable reduction of the density of vertical nanowires, which is almost null for growth on Si(111); iii) the occurrence of a higher WZ phase fraction, in particular for growth on Si(111); iv) an increase of the activation energy to release

• the less bound carrier in the radiative state from nanowires grown on GaAs(111)B; and v) a higher influence of defects on the activation of nonradiative de-excitation channels in the case of nanowires only grown on Si(111). Back-gate field effect transistors were fabricated with individual nanowires

Magnetic properties of optimized cobalt nanospheres grown by focused electron beam induced deposition (FEBID) on cantilever tips

• Soraya Sangiao,
• César Magén,
• Darius Mofakhami,
• Grégoire de Loubens and
• José María De Teresa

Beilstein J. Nanotechnol. 2017, 8, 2106–2115, doi:10.3762/bjnano.8.210

• of tip cantilevers with applications in magnetic force microscopy (MFM) [7][8][9][10] and magnetic resonance force microscopy (MRFM) [11]; (c) planar nanowires for application in magnetic domain-wall conduits [12][13], in logic circuits [14][15], in dense memory arrays [16] and for superconducting

• -vortex-lattice pinning [17]; as well as (d) three-dimensional nanowires for magnetic domain-wall studies [18][19] and for remote magnetomechanical actuation [20], quantum dots for magnetic storage [21] and catalytic purposes [22], polygonal shapes for micromagnetic studies [23][24] and spin-ice

• the growth mode, as previously reported in 3D cobalt nanowires grown by FEBID [31]. In 3D cobalt nanowires the growth occurs in a radial mode for a wire diameter greater than 120 nm, which results in higher Co content than wires with a diameter less than 80 nm, which grow in a linear mode. In order to

Systematic control of α-Fe₂O₃ crystal growth direction for improved electrochemical performance of lithium-ion battery anodes

• Nan Shen,
• Miriam Keppeler,
• Barbara Stiaszny,
• Holger Hain,
• Filippo Maglia and
• Madhavi Srinivasan

Beilstein J. Nanotechnol. 2017, 8, 2032–2044, doi:10.3762/bjnano.8.204

• α-Fe2O3 nanoparticles (e.g. nanorods with hexagonal structure, electrospun nanorods, and nanowires) or other morphologies (e.g. nanotubes, flower-like nanostructure, spindles, and hollow spheres) showed a notable electrochemical performance in the interaction with lithium. The results are also

Functional materials for environmental sensors and energy systems

• Michele Penza,
• Anita Lloyd Spetz,
• Albert Romano-Rodriguez and
• Meyya Meyyappan

Beilstein J. Nanotechnol. 2017, 8, 2015–2016, doi:10.3762/bjnano.8.201

• nanomaterials (e.g., nanowires, nanotubes, graphene, metal oxides, carbon nanostructures, large band gap semiconductors, and metals) with new sensing properties (e.g., ppb-level detection, high sensitivity, selectivity) that are self-heating and provide durable operation for low-power devices (tens of μW to