Metal oxide nanostructures: preparation, characterization and functional applications as chemical sensors

• Dario Zappa,
• Angela Bertuna,
• Elisabetta Comini,
• Navpreet Kaur,
• Nicola Poli,
• Veronica Sberveglieri and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2017, 8, 1205–1217, doi:10.3762/bjnano.8.122

• Raman spectrum of WO3 nanowire networks. All identified peaks can be attributed to tungsten trioxide, while there is no sign of alumina (corundum) peaks related to the polycrystalline substrate. This means that tungsten oxide covers the entire substrates. More specifically, the peaks at 707 cm−1 and

• outperform the results reported in literature with similar morphologies. “Small sensor system” tests In order to study these materials in real applications, metal oxide nanowires have been integrated in an electronic nose called “Small Sensor System” (S3). Nanowire devices were integrated together with

• of the source material are continually provided, the material starts to condensate in the form of a solid precipitate. The 1D crystal growth begins, and it continues as long as the source material is supplied [51]. The nanowire growth was carried out in a custom-made tubular furnace [52]. The

Vapor deposition routes to conformal polymer thin films

• Priya Moni,
• Ahmed Al-Obeidi and
• Karen K. Gleason

Beilstein J. Nanotechnol. 2017, 8, 723–735, doi:10.3762/bjnano.8.76

• bottom of the pore, the functional side wall coverage, estimated to be between 0.5 and 0.6, indicates a degree of conformality. In some cases, TEM images are necessary to verify film conformality. For instance, a conformal polysiloxane coating on an Si nanowire array is difficult to image using SEM, as

• creating nanowire cross sections by physical cleavage is nearly impossible. Using EMPA to determine the signal of constituent atoms fails as both the nanowire and polymer film contain nearly the same elements (Si and O). Previously unpublished work by Gleason and coworkers used a combination of SEM and TEM

• to verify the conformality of iCVD poly(1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane) (pV4D4) films on vertically aligned Si nanowire arrays. Figure 8a and Figure 8b show SEM images (Zeiss Merlin HR SEM) of the nanowire array before and after deposition, with no apparent change in wire

Synthesis of graphene–transition metal oxide hybrid nanoparticles and their application in various fields

• Arpita Jana,
• Elke Scheer and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2017, 8, 688–714, doi:10.3762/bjnano.8.74

• by Kumar et al. for supercapacitor applications [206]. This hybrid can also be used as an electrochemical pseudocapacitor material for potential energy storage applications [207][208]. Copper oxide (Cu2O, CuO, CuO2, Cu2O3)–graphene hybrids Cu nanowire (NW) films and indium tin oxide (ITO) films have

Modeling of the growth of GaAs–AlGaAs core–shell nanowires

• Qian Zhang,
• Peter W. Voorhees and
• Stephen H. Davis

Beilstein J. Nanotechnol. 2017, 8, 506–513, doi:10.3762/bjnano.8.54

• and Al-poor quantum dots) in the nanowire shell. There are two issues that need to be understood. One is the mechanism responsible for the morphological evolution of the shells. Analysis and simulation results suggest that deposition introduces facets not present on the equilibrium Wulff shapes. A

• heterostructure are to deposit materials with lattice parameters different from that of the wires, such as growing a Ge shell on a Si nanowire [1], so that the quantum dots form as a result of stresses generated by the lattice parameter mismatch. Recently, GaAs has been used as substrates to deposit AlGaAs on

• model for the deposition of pure materials onto a faceted nanowire. In the model, the growth of each facet is due to the deposition of atoms from the vapor and surface–atom diffusion from its neighbouring facets (Figure 2). It is suggested in experiments that bulk diffusion is negligible relative to

Self-assembly of silicon nanowires studied by advanced transmission electron microscopy

• Marta Agati,
• Guillaume Amiard,
• Vincent Le Borgne,
• Paola Castrucci,
• Richard Dolbec,
• Maurizio De Crescenzi,
• My Alì El Khakani and
• Simona Boninelli

Beilstein J. Nanotechnol. 2017, 8, 440–445, doi:10.3762/bjnano.8.47

• catalytic nanoparticle and precipitation of Si, which then crystallizes in the form of nanowire, as predicted by the VLS model [14]. Nevertheless, it should be noticed that some HAADF images revealed the presence of some nanoparticles on the SiNS surface (see point C in the inset of Figure 4b), from which

Influence of hydrofluoric acid treatment on electroless deposition of Au clusters

• Rachela G. Milazzo,
• Antonio M. Mio,
• Giuseppe D’Arrigo,
• Emanuele Smecca,
• Alessandra Alberti,
• Gabriele Fisichella,
• Filippo Giannazzo,
• Corrado Spinella and
• Emanuele Rimini

Beilstein J. Nanotechnol. 2017, 8, 183–189, doi:10.3762/bjnano.8.19

• shown quite interesting applications in the fields of Si nanowire (SiNW) catalysis [1][2][3], metal-assisted etching (MAE) [4] or even as electrical contacts in standard miniaturized devices [5]. Their ability to display enhanced surface plasmon resonance (SPR) at optical frequencies makes them

Sub-nanosecond light-pulse generation with waveguide-coupled carbon nanotube transducers

• Felix Pyatkov,
• Svetlana Khasminskaya,
• Vadim Kovalyuk,
• Frank Hennrich,
• Manfred M. Kappes,
• Gregory N. Goltsman,
• Wolfram H. P. Pernice and
• Ralph Krupke

Beilstein J. Nanotechnol. 2017, 8, 38–44, doi:10.3762/bjnano.8.5

• ). Waveguided light pulses were partly coupled out via Bragg grating couplers, designed with a central wavelength 750 ± 20 nm for guiding light into an optical fiber. Optical pulses were measured with either a single-photon avalanche detector (τ-SPAD-100, PicoQuant) or a superconducting nanowire single-photon

Controlled supramolecular structure of guanosine monophosphate in the interlayer space of layered double hydroxide

• Gyeong-Hyeon Gwak,
• Istvan Kocsis,
• Yves-Marie Legrand,
• Mihail Barboiu and
• Jae-Min Oh

Beilstein J. Nanotechnol. 2016, 7, 1928–1935, doi:10.3762/bjnano.7.184

• derivatives through hydrogen bonding [8]. They suggested those supramolecular nucleoside structures could be utilized for molecular nanowire fabrication or molecular electronics. Davis et al. prepared stable G4 hydrogels utilizing guanosine, potassium and borate [9]. Those hydrogels exhibited specific binding

Properties of Ni and Ni–Fe nanowires electrochemically deposited into a porous alumina template

• Alla I. Vorobjova,
• Dmitry L. Shimanovich,
• Kazimir I. Yanushkevich,
• Sergej L. Prischepa and
• Elena A. Outkina

Beilstein J. Nanotechnol. 2016, 7, 1709–1717, doi:10.3762/bjnano.7.163

• value of Ni–Fe NWs in the alumina template is higher than that of the Ni sample and bulk Ni, also the Curie temperature of the Ni–Fe sample (790 K) is higher than that of the Ni sample one or bulk Ni. Keywords: electrochemical deposition; nanowire; porous alumina template; specific magnetization

Effect of tetramethylammonium hydroxide/isopropyl alcohol wet etching on geometry and surface roughness of silicon nanowires fabricated by AFM lithography

• Siti Noorhaniah Yusoh and
• Khatijah Aisha Yaacob

Beilstein J. Nanotechnol. 2016, 7, 1461–1470, doi:10.3762/bjnano.7.138

• have been a few studies on the TMAH/IPA anisotropic etching, but the studies have not investigated the etched product. In this paper, we studied TMAH/IPA wet etching for the fabrication of an array of silicon nanowire patterned by AFM lithography on an SOI wafer. We investigate the relationship between

• 4 nm and gaps of 730 nm between the lines. The square-shaped pads with dimensions of 5 × 5 µm were fabricated on the left and right sides of the silicon nanowire array. Later, these patterns were etched using 25 wt % TMAH with different IPA concentrations. The results were then analysed in terms of

• the thickness or height of the fabricated silicon nanowire. Figure 3 shows that the etching depth decreases with the addition of 10 and 20 vol % IPA but then increases at 30 vol %. This trend was the same as that found in the work of Rola and Zubel [28] who explained that only a small amounts of

Dealloying of gold–copper alloy nanowires: From hillocks to ring-shaped nanopores

• Adrien Chauvin,
• Cyril Delacôte,
• Mohammed Boujtita,
• Benoit Angleraud,
• Junjun Ding,
• Chang-Hwan Choi,
• Pierre-Yves Tessier and
• Abdel-Aziz El Mel

Beilstein J. Nanotechnol. 2016, 7, 1361–1367, doi:10.3762/bjnano.7.127

• for several metals and alloys including gold, copper, silver, gold–copper and gold–silver. We demonstrate that applying an electrochemical dealloying process to the gold–copper alloy nanowire arrays allows for transforming the hillocks into ring-like shaped nanopores. The resulting porous gold

• multilayered structure observed for the main body of the nanowire (Supporting Information File 1, Figure S2). This multilayered structure, not present in case of elemental metals, is related to the substrate rotation during the co-sputter deposition [23][24]. To further study the kinetic of the nodular growth

• etching is related to the presence of boundaries between the hillocks and the rest of the nanowire body. They act as a channel promoting the propagation of the electrolyte within the material during the dealloying process. When the electrolyte penetrates through these boundaries, the hillocks become

Diameter-driven crossover in resistive behaviour of heavily doped self-seeded germanium nanowires

• Stephen Connaughton,
• Maria Koleśnik-Gray,
• Richard Hobbs,
• Olan Lotty,
• Justin D. Holmes and
• Vojislav Krstić

Beilstein J. Nanotechnol. 2016, 7, 1284–1288, doi:10.3762/bjnano.7.119

• spatial spreading of the free holes towards the nanowire centre upon diameter reduction. Keywords: diameter-dependence; germanium; nanowire; resistivity; self-seeded; Findings Semiconducting nanowires are in the focus of research due to their potential applications in electronics and optics [1][2][3][4

• centre, while close to the surface the amplitude varies much less for different diameters. For example, the scattering amplitude within the centre region of a 12 nm diameter nanowire is more than an order of magnitude higher compared to a NW of 17 nm diameter. In contrast, the amplitudes close to the NW

• region at the outside represents the nanowire shell. Dark-blue area: region of free holes near to the core/shell interface. Light-coloured area: region devoid of free holes. Trapped electrons and free holes are schematically depicted by (−) and (+), respectively. (b) Comparison between theoretical model

NO gas sensing at room temperature using single titanium oxide nanodot sensors created by atomic force microscopy nanolithography

• Li-Yang Hong and
• Heh-Nan Lin

Beilstein J. Nanotechnol. 2016, 7, 1044–1051, doi:10.3762/bjnano.7.97

• atomic force microscopy nanolithography methods, nanomachining and nano-oxidation, are employed. A single titanium nanowire (NW) is created first along with contact electrodes and a single titanium oxide ND is subsequently produced in the NW. Gas sensing is realized by the photo-activation and the photo

• potential application of single metal oxide NDs for gas sensing with a performance that is comparable with that of metal oxide nanowire gas sensors. Keywords: atomic force microscopy nanolithography; photo-activation; photo-recovery; resistive NO gas sensor; titanium oxide nanodot sensor; Introduction In

• fabrication of titanium oxide nanowire (NW) gas sensors [25][26]. NO gas sensing at low concentrations is beneficial for human health [1][2] and environmental monitoring [3]. Various types of metal oxide nanomaterials have been utilized for NO or NO2 gas sensing, e.g., SnO2 [12][15][16][17], ZnO [13][14][17

Signal enhancement in cantilever magnetometry based on a co-resonantly coupled sensor

• Julia Körner,
• Christopher F. Reiche,
• Thomas Gemming,
• Bernd Büchner,
• Gerald Gerlach and
• Thomas Mühl

Beilstein J. Nanotechnol. 2016, 7, 1033–1043, doi:10.3762/bjnano.7.96

• applicability of the concept for cantilever magnetometry by deriving magnetic information of an iron nanowire and comparing them to the results of other measurements. In our experiment we use a commercially available silicon cantilever of micrometer dimensions and an iron-filled carbon nanotube (FeCNT), the

• fabrication of such a sensor and then evaluate a magnetometry measurement and derive magnetic properties of an iron nanowire in order to prove the applicability of the concept and to indicate its potential for signal enhancement in magnetometry. Experimental Co-resonant concept By applying the harmonic

• possible to extract magnetic information from the measured frequency shift data, i.e., k3. It has been shown that in case of a FeCNT a suitable magnetic quantity is the effective magnetic monopole moment q of the iron nanowire [19][20]. Due to its single-domain magnetic structure it is acting as an

Synthesis of cobalt nanowires in aqueous solution under an external magnetic field

• Xiaoyu Li,
• Lijuan Sun,
• Hu Wang,
• Kenan Xie,
• Qin Long,
• Xuefei Lai and
• Li Liao

Beilstein J. Nanotechnol. 2016, 7, 990–994, doi:10.3762/bjnano.7.91

• an external magnetic field. The nanowires exhibited a firm linear structure without any gap. Furthermore, the diameter of the nanowire shown in the TEM image is about 60 nm, while that in Figure 1b is about 100 nm. The obvious difference in diameter observed by SEM and TEM indicated that synthesized

Magnetic switching of nanoscale antidot lattices

• Ulf Wiedwald,
• Joachim Gräfe,
• Kristof M. Lebecki,
• Maxim Skripnik,
• Felix Haering,
• Gisela Schütz,
• Paul Ziemann,
• Eberhard Goering and
• Ulrich Nowak

Beilstein J. Nanotechnol. 2016, 7, 733–750, doi:10.3762/bjnano.7.65

• minimizes its volume, in analogy to the domain wall pinning in a ferromagnetic nanowire containing a notch [43]. In turn, this pinning becomes more effective the more energy is saved by incorporating the non-magnetic defect into the domain wall, i.e., it scales with the domain wall energy. In this way, the

Finite-size effect on the dynamic and sensing performances of graphene resonators: the role of edge stress

• Chang-Wan Kim,
• Mai Duc Dai and
• Kilho Eom

Beilstein J. Nanotechnol. 2016, 7, 685–696, doi:10.3762/bjnano.7.61

• affect the resonant frequency of graphene (Equation 11). This is similar to the case of nanowire resonators, the frequency dynamics of which are not affected by the constant surface stress [28]. The frequency shift due to edge stress can be analytically understood by using the modified plate theory

• adsorption. It should be noted that the finite-size effect on the sensing performance of a graphene resonator has not been studied yet, though the finite-size effect on the sensing performance of a nanowire resonator [28] was systematically studied. In general, as described in our previous work [22], the

Determination of Young’s modulus of Sb₂S₃ nanowires by in situ resonance and bending methods

• Liga Jasulaneca,
• Raimonds Meija,
• Alexander I. Livshits,
• Juris Prikulis,
• Subhajit Biswas,
• Justin D. Holmes and
• Donats Erts

Beilstein J. Nanotechnol. 2016, 7, 278–283, doi:10.3762/bjnano.7.25

• against the tip of the cantilever. The applied load direction was adjusted perpendicular to the vertical axis of the NW. Two SEM images were recorded for each nanowire during the bending, namely one under bending load and the other one in a relaxed state. By overlapping the two images both the

Plasticity-mediated collapse and recrystallization in hollow copper nanowires: a molecular dynamics simulation

• Amlan Dutta,
• Arup Kumar Raychaudhuri and
• Tanusri Saha-Dasgupta

Beilstein J. Nanotechnol. 2016, 7, 228–235, doi:10.3762/bjnano.7.21

• , which would involve much longer time scales as compared to the plasticity-based mechanism. Keywords: dislocations; molecular dynamics; nanowire; thermal stability; Introduction Nanomaterials, as compared to bulk, are associated with large surfaces and interfaces with respect to their volume. The

• still needs to be probed through rigorous atomistic simulation without relying on the preconceived notion of diffusive transport of vacancies. In this article, we study the above-mentioned issue by performing molecular dynamics (MD) simulation of ultra-thin single crystalline copper nanowire (NW) with

• , thereby discarding the proposed mechanism of a slow diffusive route of vacancy migration. On the other hand, the collapse is found to proceed through creation of disordered atoms and plastic slips. Upon collapse, the hollow nanowire becomes partially amorphous, which heals through the recrystallization of

Blue and white light emission from zinc oxide nanoforests

• Nafisa Noor,
• Luca Lucera,
• Thomas Capuano,
• Venkata Manthina,
• Alexander G. Agrios,
• Helena Silva and
• Ali Gokirmak

Beilstein J. Nanotechnol. 2015, 6, 2463–2469, doi:10.3762/bjnano.6.255

• gap semiconductor (≈3.4 eV) with large exciton binding energy (60 meV). ZnO nanowires have been shown to yield stimulated emission with optical pumping (e.g., nanowire laser) [4] and have been demonstrated as photodetectors [5]. ZnO films have also been used in transparent thin film transistors [6

Kelvin probe force microscopy for local characterisation of active nanoelectronic devices

• Tino Wagner,
• Hannes Beyer,
• Patrick Reissner,
• Philipp Mensch,
• Heike Riel,
• Bernd Gotsmann and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2015, 6, 2193–2206, doi:10.3762/bjnano.6.225

• sideband demodulation enables robust amplitude modulated topography feedback. Finally, we demonstrate our single-scan FM-KFM technique on an active nanoelectronic device consisting of a 70 nm diameter InAs nanowire contacted by a pair of 120 nm thick electrodes. Keywords: capacitive crosstalk; frequency

• operation. In vacuum, this may require additional application of active Q control [44][45] to lower the Q-factor of the cantilever. Performance on a nanowire device To demonstrate the performance of our Kalman-KFM controller, we examine an active nanowire device as depicted in Figure 8 and Figure 9. Such

• devices exhibit some of the most typical and relevant issues hindering reliable KFM measurements in the past: a combination of large topography with a multitude of different materials including oxides prone to charging. In Figure 9, we show a scan of a 70 nm diameter indium arsenide (InAs) nanowire with

Development of a novel nanoindentation technique by utilizing a dual-probe AFM system

• Eyup Cinar,
• Ferat Sahin and
• Dalia Yablon

Beilstein J. Nanotechnol. 2015, 6, 2015–2027, doi:10.3762/bjnano.6.205

• novel applications to our nanoindentation approach. For example, while the two probes are performing a nanoindentation experiment, the third and the forth probe can be used in identifying changes in other material properties on-line. By attaching a conductive Pt nanowire probe tips, the third probe can

Simulation of thermal stress and buckling instability in Si/Ge and Ge/Si core/shell nanowires

• Suvankar Das,
• Amitava Moitra,
• Mishreyee Bhattacharya and
• Amlan Dutta

Beilstein J. Nanotechnol. 2015, 6, 1970–1977, doi:10.3762/bjnano.6.201

• proposed methodology can be extended to other materials and structures and helps with the prediction of the conditions under which a nanowire-based device might possibly fail due to elastic instability. Keywords: atomistic simulation; buckling; core–shell nanowire; thermal stress; Introduction In recent

• present features that restrict the prediction of the overall elastic modulus through simple analytical means. Decomposing the system into an isolated nanowire (core) and outer tube (shell) to apply the parallel spring model yields incorrect results due to the effect of the core–shell interface [16

• stress for elastic instability of the nanowire, which furnishes the safe limits of designing and operating parameters of these nanowire devices. Results and Discussion Simulation scheme The present study involves a series of molecular statics (MS) and molecular dynamics (MD) simulations of core/shell

Metal hydrides: an innovative and challenging conversion reaction anode for lithium-ion batteries

• Luc Aymard,
• Yassine Oumellal and
• Jean-Pierre Bonnet

Beilstein J. Nanotechnol. 2015, 6, 1821–1839, doi:10.3762/bjnano.6.186

• deposition method such as Mg/MgH2 nanowires or nanofibers are under development for a few years now [69][70][71]. For instance Mg nanowire shows interesting modifications of both thermodynamics and kinetics compared to the bulk material: a decrease of the dissociation energy of about 12%, (30–50 nm nanowires

Structural and magnetic properties of iron nanowires and iron nanoparticles fabricated through a reduction reaction

• Marcin Krajewski,
• Wei Syuan Lin,
• Hong Ming Lin,
• Katarzyna Brzozka,
• Sabina Lewinska,
• Natalia Nedelko,
• Anna Slawska-Waniewska,
• Jolanta Borysiuk and
• Dariusz Wasik

Beilstein J. Nanotechnol. 2015, 6, 1652–1660, doi:10.3762/bjnano.6.167

• nanowire surface, can additionally influence the creation of strongly distorted or amorphous iron oxides. The hyperfine parameters, especially the hyperfine magnetic field, related to iron ions belonging to the surface oxides, are thereby distributed. The hyperfine magnetic field values are very high

• material is similar, and the weight share of iron in oxides equals x = 0.7: According to the experimental results, the structures of the investigated iron nanowires as well as of iron nanoparticles can be visualized as it is presented in Figure 5. The core of nanowire or nanoparticle is crystalline α-Fe