Self-assembled quasi-hexagonal arrays of gold nanoparticles with small gaps for surface-enhanced Raman spectroscopy

• Emre Gürdal,
• Simon Dickreuter,
• Fatima Noureddine,
• Pascal Bieschke,
• Dieter P. Kern and
• Monika Fleischer

Beilstein J. Nanotechnol. 2018, 9, 1977–1985, doi:10.3762/bjnano.9.188

• , different techniques such as reactive ion etching, thermal evaporation and atomic layer deposition can be used in combination with BCML [13][14][15]. Here it is important to choose the optimum chain length of the diblock copolymers for obtaining the desired inter-particle spacing [16][17]. It is thus

• ) chloride (KAuCl4, 0.1 wt %, Sigma-Aldrich), to grow the gold precursor particles with the electroless deposition process. Reactive ion etching (Oxford Plasmalab 80 Plus) was used to remove the polymer with an oxygen plasma treatment with the following settings: process pressure 100 mTorr, power 100 W

• , temperature 20 °C and duration of the etching process 60 s. To measure the inter-particle spacing and sizes of the gold nanoparticles in this work we used a Scanning Electron Microscope (SEM) (Hitachi SU 8030). Darkfield spectroscopy The scattering spectra of gold nanoparticles were measured with a custom

Electromigrated electrical optical antennas for transducing electrons and photons at the nanoscale

• Arindam Dasgupta,
• Mickaël Buret,
• Nicolas Cazier,
• Marie-Maxime Mennemanteuil,
• Reinaldo Chacon,
• Kamal Hammani,
• Jean-Claude Weeber,
• Juan Arocas,
• Laurent Markey,
• Gérard Colas des Francs,
• Alexander Uskov,
• Igor Smetanin and
• Alexandre Bouhelier

Beilstein J. Nanotechnol. 2018, 9, 1964–1976, doi:10.3762/bjnano.9.187

• . The thickness of the nanowire and electrodes is 50 nm, including a 5 nm Ti adhesion layer. The third step is the dry etching of the TiO2 layer. For that, we first create an etching mask by electron-beam lithography, thermal deposition of a 30 nm thick nickel layer and lift-off. Reactive ion etching is

• then used to remove the TiO2 layer and to define the waveguides. More details about this etching process can be found in [62]. A last optical lithography step is carried out to define the macroscopic leads that are connected to the microscopic electrodes. The process is subsequently terminated by

Defect formation in multiwalled carbon nanotubes under low-energy He and Ne ion irradiation

• Santhana Eswara,
• Jean-Nicolas Audinot,
• Brahime El Adib,
• Maël Guennou,
• Tom Wirtz and
• Patrick Philipp

Beilstein J. Nanotechnol. 2018, 9, 1951–1963, doi:10.3762/bjnano.9.186

• [36] and their etching [37], as well as the imaging of SWCNTs [38]. After the development of a compact mass spectrometer for this instrument [39][40], the detection and imaging of sputtered ions can also be used for process control [41], including carbon-containing materials [42][43]. Whereas in

• -beam etching and takes changes in ion current during long-time irradiation into account. The scan mode with spot overlap was used for ion beam positioning, leading to a homogeneous irradiation of the sample. The experimental conditions are given in Table 2. Raman spectra Raman scattering measurements

A differential Hall effect measurement method with sub-nanometre resolution for active dopant concentration profiling in ultrathin doped Si_1−xGe_x and Si layers

• Richard Daubriac,
• Emmanuel Scheid,
• Hiba Rizk,
• Richard Monflier,
• Sylvain Joblot,
• Rémi Beneyton,
• Pablo Acosta Alba,
• Sébastien Kerdilès and
• Filadelfo Cristiano

Beilstein J. Nanotechnol. 2018, 9, 1926–1939, doi:10.3762/bjnano.9.184

• most challenging process, we show the reliability of the SC1 chemical solution (NH4OH/H2O2/H2O) with its slow etch rate, stoichiometry conservation and low roughness generation. The reliability of a complete DHE procedure, with an etching step as small as 0.5 nm, is demonstrated on a dedicated 20 nm

• , differential Hall effect (DHE) profiling [17][18] can potentially meet all the requirements related to the precise measurement of dopant activation at the semiconductor surface. DHE relies on the iteration of etching process and conventional Hall effect measurements. The active carrier profile is therefore

• nanometric resolution has been successfully demonstrated for Si and Ge, applying oxidation processes such as anodisation [19] or oxidising chemistry [20][21][22][23]. Nevertheless, etching SiGe alloys with nanometric resolution is far more challenging considering that Si and Ge have different oxidation rates

Uniform cobalt nanoparticles embedded in hexagonal mesoporous nanoplates as a magnetically separable, recyclable adsorbent

• Can Zhao,
• Yuexiao Song,
• Tianyu Xiang,
• Wenxiu Qu,
• Shuo Lou,
• Xiaohong Yin and
• Feng Xin

Beilstein J. Nanotechnol. 2018, 9, 1770–1781, doi:10.3762/bjnano.9.168

• . Mesoporous carbon nanoplates are observed after removing Co nanoparticles by HCl etching (Figure 2D). A series of hexagonal NPLs prepared with different DA concentrations and carbonization temperatures are shown in Figure S2, Supporting Information File 1. PDA layers become more noticeable with the

• , respectively; (f) LDO (Co3O4 and CoAl2O4 mixture). SEM images of: (A) pure CoAl LDH; (B) LDH@PDA-2.5 composite; (C) NPLs-2.5-800, the inset shows a high-magnification SEM image; (D) NPLs-S prepared by removal of Co nanoparticles embedded in NPLs-2.5-800 with HCl etching. (A–C) TEM images of the hexagonal

• different initial RhB concentrations of: (a) 35, (b) 25, and (c) 15 mg/L. The concentration of adsorbents is 0.2 g/L. (B) Adsorption isotherms of the hexagonal NPLs-2.5-800 sample at 25 °C (a) before (with Co nanoparticles) and (b) after (Co nanoparticles removed) HCl etching. Recyclability of the NPLs

Toward the use of CVD-grown MoS₂ nanosheets as field-emission source

• Geetanjali Deokar,
• Nitul S. Rajput,
• Junjie Li,
• Francis Leonard Deepak,
• Wei Ou-Yang,
• Nicolas Reckinger,
• Carla Bittencourt,
• Jean-Francois Colomer and
• Mustapha Jouiad

Beilstein J. Nanotechnol. 2018, 9, 1686–1694, doi:10.3762/bjnano.9.160

• deposited on SiO2 by sulfurization. The quality of the obtained NSs was analyzed by scanning electron and transmission electron microscopy, and Raman and X-ray photoelectron spectroscopy. The as-grown NSs were then successfully transferred to the substrates using a wet chemical etching method. The

Light extraction efficiency enhancement of flip-chip blue light-emitting diodes by anodic aluminum oxide

• Yi-Ru Huang,
• Yao-Ching Chiu,
• Kuan-Chieh Huang,
• Shao-Ying Ting,
• Po-Jui Chiang,
• Chih-Ming Lai,
• Chun-Ping Jen,
• Snow H. Tseng and
• Hsiang-Chen Wang

Beilstein J. Nanotechnol. 2018, 9, 1602–1612, doi:10.3762/bjnano.9.152

• with Ga-doped zinc oxide (GZO)/GaN as the base layer and then reducing the total reflectivity by changing the shape, thickness, and density of the microstructure through dry etching [12]. Li et al. increased the LEE of an InGaN-monolayer quantum-well LED by 1.8–1.9 times relative to that of a

• dislocations in the LED structure were blocked, thus enhancing the general luminous efficiency by approximately 23% [15]. Cates et al. adopted laser etching to produce a repeated microstructure on the emitting surface of a yttrium aluminum perovskite scintillation crystal activated by cerium (formula YAlO3:Ce

• evident in Figure 2b. Figure 2h shows pores that have been etched excessively. Excessive etching destroys the surface structure. Figure 2e shows pores that have been completely etched. These results are consistent with the SEM measurements. We measured the line-scan profile of the AFM images to determine

Interaction-tailored organization of large-area colloidal assemblies

• Silvia Rizzato,
• Elisabetta Primiceri,
• Anna Grazia Monteduro,
• Adriano Colombelli,
• Angelo Leo,
• Maria Grazia Manera,
• Roberto Rella and
• Giuseppe Maruccio

Beilstein J. Nanotechnol. 2018, 9, 1582–1593, doi:10.3762/bjnano.9.150

• . Successively, reactive ion etching was used to selectively remove the portion of the gold film not protected by the nanospheres. The etch rate (2.9 nm/min) was estimated measuring the thickness of the gold film for different etching times. Finally, the nanosphere residues were removed by oxygen plasma

• and nanoholes of different sizes and materials were realized. Figure 4a,b shows gold nanodisks of 500 nm still covered by the nanosphere portion remaining after the etching process, while in Figure 4c,d images of the final disks of different diameters are reported. Gold and cobalt nanoholes realized

Evaluation of replicas manufactured in a 3D-printed nanoimprint unit

• Manuel Caño-García,
• Morten A. Geday,
• Manuel Gil-Valverde,
• Xabier Quintana and
• José M. Otón

Beilstein J. Nanotechnol. 2018, 9, 1573–1581, doi:10.3762/bjnano.9.149

• UV-curable molds. In either case, the samples can be used as such, or undergo further processes such as chemical etching [6] or electric-field-assisted steps [7]. In recent months, we have developed a NIL system [8] using free software and public hardware designs created in a simple 3D printer. The

Correlative electrochemical strain and scanning electron microscopy for local characterization of the solid state electrolyte Li_1.3Al_0.3Ti_1.7(PO₄)₃

• Nino Schön,
• Deniz Cihan Gunduz,
• Shicheng Yu,
• Hermann Tempel,
• Roland Schierholz and
• Florian Hausen

Beilstein J. Nanotechnol. 2018, 9, 1564–1572, doi:10.3762/bjnano.9.148

• surface features as observed by SEM, providing evidence that both methods can be applied complementary. The same pores as those observed via SEM can be found in the AFM topography image and the topography reveals some preferential etching at the grain boundaries and interfaces. Differentiation between the

• individual grains can hardly be seen in the topography image (Figure 4c), using the same color scale as in Figure 2. This means, preparation with the ion beam almost parallel to the surface introduces less preferential etching of the grain boundaries. However, the ESM amplitude signal, as shown in Figure 4d

Optical near-field mapping of plasmonic nanostructures prepared by nanosphere lithography

• Gitanjali Kolhatkar,
• Alexandre Merlen,
• Jiawei Zhang,
• Chahinez Dab,
• Gregory Q. Wallace,
• François Lagugné-Labarthet and
• Andreas Ruediger

Beilstein J. Nanotechnol. 2018, 9, 1536–1543, doi:10.3762/bjnano.9.144

• laser onto a gold tip. A schematic of the experimental setup can be found elsewhere [37]. The elastically backscattered signal detected by a PMT was studied here. To obtain a tip with a radius down to 10 nm and low surface roughness, the gold tips were fabricated by electrochemical etching. A 100 µm

Cr(VI) remediation from aqueous environment through modified-TiO₂-mediated photocatalytic reduction

• Rashmi Acharya,
• Brundabana Naik and
• Kulamani Parida

Beilstein J. Nanotechnol. 2018, 9, 1448–1470, doi:10.3762/bjnano.9.137

• for efficient photocatalytic Cr(VI) reduction [134]. They prepared the photocatalyst using a direct-wrapped route followed by hydrothermal etching. The high charge separation efficiency and redox ability are due to the synergetic effect of formation of a Z scheme photocatalytic process and its

Preparation and morphology-dependent wettability of porous alumina membranes

• Dmitry L. Shimanovich,
• Alla I. Vorobjova,
• Daria I. Tishkevich,
• Alex V. Trukhanov,
• Maxim V. Zdorovets and
• Artem L. Kozlovskiy

Beilstein J. Nanotechnol. 2018, 9, 1423–1436, doi:10.3762/bjnano.9.135

• obtained. Five samples were prepared in total. For samples 1, 2, and 3 the etching of the barrier layer was carried out by immersing the entire membrane in a 4% aqueous solution of phosphoric acid (H3PO4) at 35 ± 2 °C for 15, 20 and 35 minutes, respectively. For the as-produced samples of type I and type

• pore sizes and oxide thickness using various etching technologies of the barrier layer at the bottom of the pores (Table 1). In Figure 2 the option of barrier layer etching on both sides (bilateral etching) by immersion of all free membrane in solution (sample No. 2) is shown. In the free membrane the

• various options for barrier layer etching are closely associated with the liquid distribution in the narrow channels (pores) of the PAM. Preliminary results show that a membrane thickness of less than 30 µm is enough to carry out an usual bilateral etching by immersion of the entire membrane into solution

Nanoporous silicon nitride-based membranes of controlled pore size, shape and areal density: Fabrication as well as electrophoretic and molecular filtering characterization

• Axel Seidenstücker,
• Stefan Beirle,
• Fabian Enderle,
• Paul Ziemann,
• Othmar Marti and
• Alfred Plettl

Beilstein J. Nanotechnol. 2018, 9, 1390–1398, doi:10.3762/bjnano.9.131

• -defined Au nanoparticles (NPs) exhibiting a high degree of hexagonal order as obtained in a first step by a proven micellar approach. These NP arrays serve as masks in a second reactive ion etching (RIE) step optimized for etching Si and some important Si compounds (silicon oxide, silicon nitride) on the

• approach came from diverse ion-track etching techniques with a limitation in porosity but several ways to form pore shapes [10][11][12]. Alternatively, thin porous nanocrystalline silicon (pnc-Si) membranes have been suggested with pores formed in a nc-silicon film sandwiched between nanometer-thick

• defined nanopores restricts them to small numbers of pores or specific arrangements, hindering high throughput [21][22]. With this aspect in mind, parallel fabrication techniques, based on self-assembly of polymeric components, become essential in combination with appropriate etching procedures. For this

Electrostatically actuated encased cantilevers

• Benoit X. E. Desbiolles,
• Gabriela Furlan,
• Adam M. Schwartzberg,
• Paul D. Ashby and
• Dominik Ziegler

Beilstein J. Nanotechnol. 2018, 9, 1381–1389, doi:10.3762/bjnano.9.130

• length l of the free resonator, however, is set by the etching duration. Located inside the encasement its exact length is not easily measurable. Hence, we determine it from the resulting resonance frequency. The frequency of a tip-less beam in vacuum is well known and given by f0 = 0.162 (t/l2), where

Chemistry for electron-induced nanofabrication

• Petra Swiderek,
• Hubertus Marbach and
• Cornelis W. Hagen

Beilstein J. Nanotechnol. 2018, 9, 1317–1320, doi:10.3762/bjnano.9.124

• beams can be used to induce, on a very small area, chemical reactions of adsorbed precursor molecules that either lead to etching of the underlying surface or deposition of material. The latter additive variant of FEBIP is focused electron beam induced deposition (FEBID), a powerful direct-write

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

• irradiation of laser light. A PMMA/MMA bilayer resist was used for electron-beam lithography to prepare the resist pattern on the Py thin film followed by argon ion milling at a base pressure of 1 × 10−4 Torr with a beam current of 60 mA for 6 min for etching out the Py film from everywhere except the

A simple extension of the commonly used fitting equation for oscillatory structural forces in case of silica nanoparticle suspensions

• Sebastian Schön and
• Regine von Klitzing

Beilstein J. Nanotechnol. 2018, 9, 1095–1107, doi:10.3762/bjnano.9.101

• ± 2 nm [34]. Silicon wafers (Wacker Chemie) were used as substrates. Preparation The silicon wafers were cleaned prior to each experiment by etching in a 1:1:5 solution of hydrogen peroxide (30% Th. Geyer GmbH & Co KG), ammonium hydroxide (30–33% Carl Roth GmbH & Co KG) and water at 60 °C for 10 min

Facile chemical routes to mesoporous silver substrates for SERS analysis

• Elina A. Tastekova,
• Alexander Y. Polyakov,
• Anastasia E. Goldt,
• Alexander V. Sidorov,
• Alexandra A. Oshmyanskaya,
• Irina V. Sukhorukova,
• Dmitry V. Shtansky,
• Wolgang Grünert and
• Anastasia V. Grigorieva

Beilstein J. Nanotechnol. 2018, 9, 880–889, doi:10.3762/bjnano.9.82

• long time in air. Mesoporous noble metals are mostly used as catalysts for high surface energy, gas sensor components, cell imaging mediators, etc. [5]. The most popular methods for mesoporous metal processing include acidic etching of bimetallic molts [6], electrochemical dealloying [7

• ], electroplating using templates [8], electrophoretic deposition of nanoparticles [9] and diverse techniques of hollow porous structure formation, for example, by aerosol pyrolysis or by smart chemical etching. The latter includes selective chemical etching of one metal component [10][11] or etching during

• galvanic replacement [12]. Among other relevant strategies, nanoparticle aggregation [13][14] or direct deposition of porous films without templates [15][16] should be mentioned. Chemical etching is a technically low demand process – an important advantage of this technique. However, it requires that the

The effect of atmospheric doping on pressure-dependent Raman scattering in supported graphene

• Egor A. Kolesov,
• Mikhail S. Tivanov,
• Olga V. Korolik,
• Olesya O. Kapitanova,
• Xiao Fu,
• Hak Dong Cho,
• Tae Won Kang and
• Gennady N Panin

Beilstein J. Nanotechnol. 2018, 9, 704–710, doi:10.3762/bjnano.9.65

• /isopropyl alcohol mixture was used to wash graphene from etching products [31]. PMMA was removed by submerging the sample in glacial acetic acid (extra pure) [32] for 4 h. Graphene, doped with nitrogen, was prepared using a nitrogen-plasma treatment described elsewhere [33]. The Raman spectra were obtained

Perovskite-structured CaTiO₃ coupled with g-C₃N₄ as a heterojunction photocatalyst for organic pollutant degradation

• Ashish Kumar,
• Christian Schuerings,
• Suneel Kumar,
• Ajay Kumar and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2018, 9, 671–685, doi:10.3762/bjnano.9.62

• at 550 °C with a temperature ramp of 3 °C/min for 4 h in static air and allowed to cool naturally to room temperature. The resultant yellow mass was well ground to form a fine powder. The thus-obtained powder was subjected to thermal oxidation etching in static air at 500 °C for 2 h with a ramp rate

Facile synthesis of ZnFe₂O₄ photocatalysts for decolourization of organic dyes under solar irradiation

• Arjun Behera,
• Debasmita Kandi,
• Sanjit Manohar Majhi,
• Satyabadi Martha and
• Kulamani Parida

Beilstein J. Nanotechnol. 2018, 9, 436–446, doi:10.3762/bjnano.9.42

• in 120 min [19]. The photocatalytic activity of ZnFe2O4 has also been tested in the degradation of Rh B [24]. Zhao et al. have synthesized ZnFe2O4 through chemical etching followed by calcination and reported a degradation rate of 31% in 3 h [24]. Doong and co-workers have prepared ZnFe2O4 through a

Blister formation during graphite surface oxidation by Hummers’ method

• Olga V. Sinitsyna,
• Georgy B. Meshkov,
• Anastasija V. Grigorieva,
• Alexander A. Antonov,
• Inna G. Grigorieva and
• Igor V. Yaminsky

Beilstein J. Nanotechnol. 2018, 9, 407–414, doi:10.3762/bjnano.9.40

• wavy, probably due to the etching by the oxidation mixture. We found that the blister density becomes larger before the large cleavage steps (more than 10 nm). We believe that the blisters cannot expand under a rather thick graphite layer because of its high rigidity. The blisters did not form only

The nanofluidic confinement apparatus: studying confinement-dependent nanoparticle behavior and diffusion

• Stefan Fringes,
• Felix Holzner and
• Armin W. Knoll

Beilstein J. Nanotechnol. 2018, 9, 301–310, doi:10.3762/bjnano.9.30

• photolithography. Third, the masking layer was removed by wet etching (TechniEtch ACI2, MicroChemicals and TechniStrip Cr01, MicroChemicals) of the unprotected areas, leaving behind a central metal-resist stack defining the position of the mesa. The area around the stack was etched for 75 s by concentrated

• hydrofluoric acid (49% HF) to define the mesa. A mesa height of 40–45 μm was measured with a profilometer (Dektak, Veeco), corresponding to an etch rate of ≈36 μm/min, similar to the rate observed by Zhu et al. [24]. Finally, the remaining masking layer was removed by etching, and the processed cover glass was

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

• nanomanipulation approaches. The top-down approach involves lithography, etching and coating technologies to fabricate device structures from bulk materials or thin films [7][19][23][39][47][48][49][50]. The combined approach of fabricating NEM switches requires subsequent transfer and alignment of synthesized

• was followed by etching of the SiO2 sacrificial layer for the release of Mo switching structures [19][115]. Switches with 300 nm thick and 500–700 nm wide switching elements with lengths 28–40 µm showed jump-in voltages in the range of 12–24 V for separation gaps of 100–150 nm. Cycling tests performed

• the best-achieved turn-on delay of 400 ns. When tested for durability, the Ru device withstood more than 2 × 106 switching cycles at 1 kHz frequency. However, when downscaling Ru NEM switches, residual stress must be accurately controlled to avoid the buckling of beams after etching of the sacrificial