Al₂O₃/TiO₂ inverse opals from electrosprayed self-assembled templates

• Arnau Coll,
• Sandra Bermejo,
• David Hernández and
• Luís Castañer

Beilstein J. Nanotechnol. 2018, 9, 216–223, doi:10.3762/bjnano.9.23

• size) or silicon dioxide nanoparticles with dimensions typically several hundreds of micrometers with a close packed, face-centered cubic, three-dimensional order. In parallel we have shown the use of Al2O3 as a good candidate for the inverse opal supporting layer regarding the low temperature

• errors and Al2O3/TiO2 as a structural layer infiltrated through the voids. This is a two-step atomic layer deposition (ALD) process in which the polymeric template is eliminated after the deposition of the alumina layer and before the ALD deposition of the titania layer. Results and Discussion The

• fabrication process of the Al2O3/TiO2 inverse opals is schematically outlined in Figure 1 where the starting step can be seen in Figure 1a and consists of the electrospray deposition of the template layer of ordered polystyrene nanoparticles. Only a side view of one row of four nanoparticles is shown for

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

• reconstruction should be on the NW top polar facet [20] enabling good bonding of Ga atoms, while on nonpolar sidewalls, the adsorbed atoms are weakly bonded and diffuse to the top facet or can be desorbed. Self-induced formation of NWs has been discovered on Al2O3 [21] and was successfully reproduced on other

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

• interlayer Al2O3 between the superconducting Nb electrodes, and its thickness d ≈ 1 nm. The critical current density value lies typically in the range jc = 10–100 μA/μm2. The corresponding specific capacitance of the Josephson junction is c ≈ 40–60 fF/μm2. A variation of the critical current of a Josephson

Exploring wear at the nanoscale with circular mode atomic force microscopy

• Olivier Noel,
• Aleksandar Vencl and
• Pierre-Emmanuel Mazeran

Beilstein J. Nanotechnol. 2017, 8, 2662–2668, doi:10.3762/bjnano.8.266

• . Finally, we describe the advantages of this method and we report a relevant application example addressing a Cu/Al2O3 nanocomposite material used in industrial applications. Keywords: circular mode atomic force microscopy; composite materials; image processing; nanowear; wear mechanisms; Introduction

• and erratic, their related trends regarding Cu/Al2O3 nanocomposites at the nanoscale may be obtained. Experimental The investigated copper-based nanocomposite was produced by powder metallurgy technology and contained approximately 4.7 wt % of nanometer-sized Al2O3 particles (the average diameter was

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

• an Al2O3 layer on a silicon sample. A peculiar lift-up of the Fe seed structures as “flakes” was observed and the mechanism was discussed. Finally, a proof-of-principle was presented showing that EBID deposits from the precursor Co(CO)3NO are also very effective catalysts for the CNT growth. Even

• , for the formation of high-density vertically aligned CNTs (referred to as CNT forests), a thin Al2O3 layer was introduced to improve the CNT yield grown on EBID Fe deposits. The significant increase in the yield can be attributed to the reduced mobility of the Fe deposits on the Al2O3 substrate

• forests on Al2O3 support layer After the successful exploration of the localized fabrication of individual CNTs at a predefined position, the next step was to target the growth of CNT forests which represent appealing materials for different applications, such as super-capacitor electrodes [6][37

Refractive index sensing and surface-enhanced Raman spectroscopy using silver–gold layered bimetallic plasmonic crystals

• Somi Kang,
• Sean E. Lehman,
• Matthew V. Schulmerich,
• An-Phong Le,
• Tae-woo Lee,
• Stephen K. Gray,
• Rohit Bhargava and
• Ralph G. Nuzzo

Beilstein J. Nanotechnol. 2017, 8, 2492–2503, doi:10.3762/bjnano.8.249

• penetration of liquid solution into the interfaces formed between the metal films and the SOG substrate. To prevent the degradation in performance that this engendered, a conformal ≈6 nm thick Al2O3 passivation film was deposited on top of the metal by atomic layer deposition (Cambridge Nanotech). Bulk

• and calculated normal incidence transmission spectra and electric field distributions around the nanoholes for full-3D PCs with Au50 (Figure 2a), Ag50 (Figure 2b), and Ag30Au20 (Figure 2c) mass-coverage metal films. The Al2O3 passivation layer was not included in the calculations as it was found to

Laser-assisted fabrication of gold nanoparticle-composed structures embedded in borosilicate glass

• Nikolay Nedyalkov,
• Mihaela Koleva,
• Nadya Stankova,
• Rosen Nikov,
• Mitsuhiro Terakawa,
• Yasutaka Nakajima,
• Lyubomir Aleksandrov and
• Reni Iordanova

Beilstein J. Nanotechnol. 2017, 8, 2454–2463, doi:10.3762/bjnano.8.244

• % Al2O3, 20% B2O3, 5% CaO, 2% Li2O, 3% MgO, where AuCl3 is added to the initial mixture in an amount ensuring 0.015 wt % of Au in the final glass sample. The mixed material is melted in a Pt crucible and kept at a temperature of 1450 °C for three hours. After cooling, the glass sample is cut into pieces

• large amounts of B2O3 and Al2O3, a contribution of defect absorption induced by modification of the bond in these oxides should also be considered. According to Sakka [29], defects induced in borate glasses have strong absorption in the visible range, peaking at about 590 nm. For alumina-based glasses

Increasing the stability of DNA nanostructure templates by atomic layer deposition of Al₂O₃ and its application in imprinting lithography

• Hyojeong Kim,
• Kristin Arbutina,
• Anqin Xu and
• Haitao Liu

Beilstein J. Nanotechnol. 2017, 8, 2363–2375, doi:10.3762/bjnano.8.236

• conformal coating with a nanometer-thin protective inorganic oxide layer created using atomic layer deposition (ALD). DNA nanotubes and origami triangles were coated with ca. 2 nm to ca. 20 nm of Al2O3. Nanoscale features of the DNA nanostructures were preserved after the ALD coating and the patterns are

• resistive to UV/O3 oxidation. The ALD-coated DNA templates were used for a direct pattern transfer to poly(L-lactic acid) films. Keywords: aluminium oxide (Al2O3); atomic layer deposition; DNA nanostructure; nanofabrication; nanoimprint lithography; pattern transfer; polymer stamp; replica molding

• Al2O3 onto the nanostructures followed by thermal annealing [36]. In addition to the 2D pattern transfer processes, gold nanoparticles with specified 3D shapes were synthesized by growing seed particles in the internal cavities of 3D DNA nanostructures [37][38]. Compared to the above developments, there

Ta₂N₃ nanocrystals grown in Al₂O₃ thin layers

• Krešimir Salamon,
• Maja Buljan,
• Iva Šarić,
• Mladen Petravić and
• Sigrid Bernstorff

Beilstein J. Nanotechnol. 2017, 8, 2162–2170, doi:10.3762/bjnano.8.215

• -Sincrotrone Trieste, Strada Statale 14, km 163.5, I-34149 Basovizza (TS), Italy 10.3762/bjnano.8.215 Abstract Tantalum nitride nanoparticles (NPs) and cubic bixbyite-type Ta2N3 nanocrystals (NCs) were grown in (Ta–N+Al2O3)/Al2O3 periodic multilayers (MLs) after thermal treatment. The MLs were prepared by

• nitride NPs could be confined within the metallic layers. Here we tested the feasibility of this procedure with the tantalum nitride (Ta–N) system, more specifically with the cubic bixbyite type (space group 206, ) Ta2N3 nanocrystals embedded within the Al2O3 matrix. The Ta–N system has a uniquely rich

• (nitrogen fraction in sputtering gas mixture pN2 = 0.2) with a total gas pressure of 0.47 Pa. Ta (99.95% purity) and Al2O3 (99.995% purity) targets were used in dc (15 W) and rf (140 W) operated magnetrons, respectively. The deposition rates were 0.31 nm/s for the Ta target and 0.19 nm/s for the Al2O3

A comparative study of the nanoscale and macroscale tribological attributes of alumina and stainless steel surfaces immersed in aqueous suspensions of positively or negatively charged nanodiamonds

• Colin K. Curtis,
• Antonin Marek,
• Alex I. Smirnov and
• Jacqueline Krim

Beilstein J. Nanotechnol. 2017, 8, 2045–2059, doi:10.3762/bjnano.8.205

• materials. Alumina (Al2O3) ball and the disk contacts were purchased from PCS Instruments (London, United Kingdom), with respective part #’s MTMB3/4AL2O3 and MTMD3/4AL2O3. Stainless steel (AISI 52100) polished ball and the disk contacts were also purchased from PCS Instruments (London, United Kingdom), with

• and the sample was then immersed into 4 wt % oxalic acid solution maintained at 0 °C. A cathode was placed in the bath and an electric potential of 40 V was applied between the anode and the cathode. Anodization was halted at 3 min yielding an approximately 100 nm thick Al2O3 layer. After the

• aluminum, the surface-exposed aluminum metal is readily oxidized to Al2O3 under ambient air. This surface layer of alumina is protecting the rest of metal from a further corrosion. In our experiments, the electrodes were additionally anodized for 3 min. This procedure is expected to yield approximately 50

Fluorination of vertically aligned carbon nanotubes: from CF₄ plasma chemistry to surface functionalization

• Claudia Struzzi,
• Mattia Scardamaglia,
• Jean-François Colomer,
• Alberto Verdini,
• Luca Floreano,
• Rony Snyders and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2017, 8, 1723–1733, doi:10.3762/bjnano.8.173

• vapor deposition (CCVD) at atmospheric pressure. The catalysts are prepared by magnetron sputtering: a 30 nm Al2O3 buffer layer is deposited on Si wafers with native SiO2 and a 6 nm Fe layer is then deposited to form nanoparticles which catalyse the vCNT growth. Then, the substrate is placed inside the

Three-in-one approach towards efficient organic dye-sensitized solar cells: aggregation suppression, panchromatic absorption and resonance energy transfer

• Jayita Patwari,
• Samim Sardar,
• Bo Liu,
• Peter Lemmens and
• Samir Kumar Pal

Beilstein J. Nanotechnol. 2017, 8, 1705–1713, doi:10.3762/bjnano.8.171

• proximity. To create this proximity between these two dyes Al2O3 has been used. The excited-state lifetime of PPIX (attached to Al2O3) was measured in presence and absence of SQ2 by fitting the time-resolved fluorescence decays (Figure 2b). It can be noted from the lifetime components summarized in Table 1

• that the average lifetime of the PPIX excited state (attached to Al2O3) is shortened from 13.20 to 5.47 ns when SQ2 is added to the solution. We propose FRET between the donor (PPIX) and the acceptor (SQ2) as the mechanistic explanation of the shortened lifetime of the excited donor state. The

• concurrently fulfilled by PPIX. Structure of (a) PPIX and (b) SQ2; (c) normalized absorption spectra of PPIX in DMSO and SQ2 in ethanol. (a) Spectral overlap between the emission of PPIX and the absorption of SQ2, (b) The picosecond-resolved fluorescence decays of PPIX attached to Al2O3 in absence (red) and

Low-temperature CO oxidation over Cu/Pt co-doped ZrO₂ nanoparticles synthesized by solution combustion

• Amit Singhania and
• Shipra Mital Gupta

Beilstein J. Nanotechnol. 2017, 8, 1546–1552, doi:10.3762/bjnano.8.156

• , different types of catalysts including monometallic (e.g., Pt, Pd, Rh, Au, Ni, Co and Sn), bimetallic (e.g., Pd–Au, Pd–Rh, Pt–Co, Cu–Rh, Au–Cu and Au–Ag) along with various types of supports (e.g., CeO2, SiO2, Al2O3, Co3O4, Fe2O3, activated carbon (AC), carbon nanotubes (CNTs) and ZrO2) have been reported

• acidic reaction environments [18] and a better catalyst/support than other materials such as SiO2, TiO2, and Al2O3 [19]. Recently, we reported the usage of ZrO2 and Pt-doped ZrO2 nanoparticles for CO oxidation [20]. In this paper, the synthesized ZrO2 showed 100% CO conversion at a temperature which is

Parylene C as a versatile dielectric material for organic field-effect transistors

• Tomasz Marszalek,
• Maciej Gazicki-Lipman and
• Jacek Ulanski

Beilstein J. Nanotechnol. 2017, 8, 1532–1545, doi:10.3762/bjnano.8.155

• insulating material. The capacitance is determined by the dielectric permittivity (ε) and the thickness of the insulating layer. Currently, two types of dielectric materials are commonly employed in transistor design and construction, either inorganic metal oxides (such as Ta2O5, Al2O3, SiO2) or organic

Fabrication of hierarchically porous TiO₂ nanofibers by microemulsion electrospinning and their application as anode material for lithium-ion batteries

• Jin Zhang,
• Yibing Cai,
• Xuebin Hou,
• Xiaofei Song,
• Pengfei Lv,
• Huimin Zhou and
• Qufu Wei

Beilstein J. Nanotechnol. 2017, 8, 1297–1306, doi:10.3762/bjnano.8.131

• without the need of a complex spinneret. It is a simple and versatile way to prepare nanofibers with hollow or multichannel structures [26]. More importantly, various inorganic nanofibers can be fabricated easily by ME-ES including TiO2, SiO2, ZrO2, SnO2, V2O5, GeO2 and Al2O3. A microemulsion system was

Fully scalable one-pot method for the production of phosphonic graphene derivatives

• Kamila Żelechowska,
• Marta Prześniak-Welenc,
• Marcin Łapiński,
• Izabela Kondratowicz and
• Tadeusz Miruszewski

Beilstein J. Nanotechnol. 2017, 8, 1094–1103, doi:10.3762/bjnano.8.111

• subtracted from the experimental results. To avoid heat and mass transfer limitations, approximately 8 × 10−6 kg of sample was used, and Al2O3 crucibles with lids were employed. The total uncertainty associated with measurement was 0.005% by weight of the sample and was included in the final result. The

The integration of graphene into microelectronic devices

• Guenther Ruhl,
• Sebastian Wittmann,
• Matthias Koenig and
• Daniel Neumaier

Beilstein J. Nanotechnol. 2017, 8, 1056–1064, doi:10.3762/bjnano.8.107

• yields excellent results [4], but this is not a production-relevant approach. A material that is available in mass-production quantities and fulfills both mentioned requirements is aluminum oxide deposited by atomic-layer deposition (ALD). It was demonstrated that graphene encapsulated in Al2O3 could be

• passivated (Figure 4) and was stable for a longer period of time under ambient conditions [50]. The main problem of growing Al2O3 by ALD is to obtain a continuous nucleation layer on graphene to start the deposition. To solve this problem several approaches are proposed. One solution is the deposition of a

• few nanometers thin Al layer on graphene and subsequently oxidizing it in air to generate a thin start layer for a subsequent ALD process depositing several tens of nanometers of Al2O3 [50]. Further there is an adapted nucleation process using water and trimethylaluminium (TMA) as precursors at

Study of the correlation between sensing performance and surface morphology of inkjet-printed aqueous graphene-based chemiresistors for NO₂ detection

• F. Villani,
• C. Schiattarella,
• T. Polichetti,
• R. Di Capua,
• F. Loffredo,
• B. Alfano,
• M. L. Miglietta,
• E. Massera,
• L. Verdoliva and
• G. Di Francia

Beilstein J. Nanotechnol. 2017, 8, 1023–1031, doi:10.3762/bjnano.8.103

• comparing the response of different chemiresistors fabricated by dispensing the same suspension also onto Al2O3 and Si/SiO2 substrates and carrying out a supportive atomic force microscopy analysis. The results prove the possibility to produce sensor devices by means of a wholly environmentally friendly

• chemiresistor have been analysed upon NO2 exposure at standard ambient temperature and pressure. Moreover, as comparison, inkjet-printed sensors have been manufactured on standard insulating substrates, namely alumina (Al2O3), and silicon dioxide (Si/SiO2). They have been characterized through gas sensing and

• performed analyses point out that the physical parameters of the dispersion are suitable for the IJP technique. After having verified the jettability, the graphene ink has been dispensed onto paper and on two the standard insulating substrates Al2O3 and Si/SiO2. The devices have been manufactured according

Diffusion and surface alloying of gradient nanostructured metals

• Zhenbo Wang and
• Ke Lu

Beilstein J. Nanotechnol. 2017, 8, 547–560, doi:10.3762/bjnano.8.59

• the diffusion activation enthalpy is slightly lower than that that of GB diffusion. In addition, the Cr-diffusion depth values were determined in GNS low carbon steel samples chromized in a packed powder mixture of Cr–NH4Cl–Al2O3, as shown in Figure 2 [32]. One can see that the diffusion depth into

Advances in the fabrication of graphene transistors on flexible substrates

• Gabriele Fisichella,
• Stella Lo Verso,
• Silvestra Di Marco,
• Vincenzo Vinciguerra,
• Emanuela Schilirò,
• Salvatore Di Franco,
• Raffaella Lo Nigro,
• Fabrizio Roccaforte,
• Amaia Zurutuza,
• Alba Centeno,
• Sebastiano Ravesi and
• Filippo Giannazzo

Beilstein J. Nanotechnol. 2017, 8, 467–474, doi:10.3762/bjnano.8.50

• buried gate contact under a thin Al2O3 insulating film. In order to be compatible with the use of the PEN substrate, optimized deposition conditions of the Al2O3 film by plasma-enhanced atomic layer deposition (PE-ALD) at a low temperature (100 °C) have been developed without any relevant degradation of

• in graphene FETs (Gr-FETs) even with gradually scaled (≈0.5 µm) channel lengths fabricated on a flexible polyimide substrate and adopting a back-gate configuration and Al2O3 as a gate dielectric. In addition, due to the low density of states (DOS) around the Dirac point, the carrier density of

• applications. In this case the thickness and the dielectric constant of the insulating film have crucial importance in order to maintain a reasonably high gate capacitance of the final device. In particular, considering high κ-dielectrics such as HfO2 or Al2O3 with film thickness in the order of 10 nm, the

Nanocrystalline ZrO₂ and Pt-doped ZrO₂ catalysts for low-temperature CO oxidation

• Amit Singhania and
• Shipra Mital Gupta

Beilstein J. Nanotechnol. 2017, 8, 264–271, doi:10.3762/bjnano.8.29

• anthropogenic activities. The catalytic CO oxidation is a very well established and exploited process. So far, noble metals such as Pt, Pd, Rh and Au dominated as catalysts for CO oxidation [10][11][12]. Various supports such as Al2O3, TiO2, SiO2, CeO2, Fe2O3 and carbon nanotubes (CNTs) have also been used for

• used as catalyst/support because of its high activity and thermal stability. The advantages also include its inertness under acidic reaction environments [17]. Also, it is reported as a better catalyst and support than many other materials, such as Al2O3, TiO2 and SiO2 [18]. It has been used by

Tunable plasmons in regular planar arrays of graphene nanoribbons with armchair and zigzag-shaped edges

• Cristian Vacacela Gomez,
• Michele Pisarra,
• Mario Gravina and
• Antonello Sindona

Beilstein J. Nanotechnol. 2017, 8, 172–182, doi:10.3762/bjnano.8.18

• detected in large-width, extrinsic GNR arrays fabricated on Al2O3 [26]. The surface plasmon of ZGNRs is originated by the large DOS peak observed at the Fermi level EF (Figure 1a,c). This mode shows a -like dispersion [31] and seems to be analogous to the conventional 2D plasmons of extrinsic graphene [19

Annealing-induced recovery of indents in thin Au(Fe) bilayer films

• Anna Kosinova,
• Ruth Schwaiger,
• Leonid Klinger and
• Eugen Rabkin

Beilstein J. Nanotechnol. 2016, 7, 2088–2099, doi:10.3762/bjnano.7.199

• underlayer) were deposited on c-plane sapphire (α-Al2O3) substrates at room temperature using electron beam deposition. The deposition took place in a VST e-beam evaporator with a base pressure of 5 × 10−7 Torr (6.7 × 10−7 mbar). Deposition rates were 0.2–0.3 Å·s−1 for Fe and 0.7 Å·s−1 for Au. After the

The difference in the thermal conductivity of nanofluids measured by different methods and its rationalization

• Aparna Zagabathuni,
• Sudipto Ghosh and
• Shyamal Kumar Pabi

Beilstein J. Nanotechnol. 2016, 7, 2037–2044, doi:10.3762/bjnano.7.194

• thermal conductivity of water-based Al2O3 nanofluids using the LFM. They observed that at room temperature the enhancement in thermal conductivity for 4 vol % of Al2O3-nanoparticle loading was around 4.95%, whereas Beck et al. [4] obtained 16.5% enhancement using the transient hot-wire method for the same

• Al2O3 nanoparticle loading and particle size. Lee et al. [25] have investigated the thermal conductivity of Al2O3, SiC, Ni, ZnO and multiwalled carbon nanotubes (MWCNTs) in liquid gallium using LFM. They reported that the thermal conductivity measured by LFM was not accurate because of the uncertainty

• insignificant, if the dispersed material was ceramic (typically Al2O3). In this paper we put forward a quantitative analysis based on the collision-mediated heat transfer model for water-based Al2O3 nanofluids, which can account for the difference in the thermal conductivity values of nanofluids obtained by LFM

Effect of nanostructured carbon coatings on the electrochemical performance of Li_1.4Ni_0.5Mn_0.5O_2+x-based cathode materials

• Konstantin A. Kurilenko,
• Oleg A. Shlyakhtin,
• Oleg A. Brylev,
• Dmitry I. Petukhov and
• Alexey V. Garshev

Beilstein J. Nanotechnol. 2016, 7, 1960–1970, doi:10.3762/bjnano.7.187

• modification, namely other cathode materials (LiMnPO4 [11], LiMn2O4 [12], LiCoO2 [13], LiNiO2 [14]) or simple binary compounds such as CaF2 [15], TiO2 [16], ZnO [17] and Al2O3 [18]. During the assembly of the lithium-ion cells, the cathode materials are always mechanically mixed with carbon black in order to