A new approach to grain boundary engineering for nanocrystalline materials

• Shigeaki Kobayashi,
• Sadahiro Tsurekawa and
• Tadao Watanabe

Beilstein J. Nanotechnol. 2016, 7, 1829–1849, doi:10.3762/bjnano.7.176

• performance nanocrystalline or submicrometer-grained materials with desirable mechanical properties such as enhanced fracture resistance. Finally, the potential power of GBE is demonstrated for high performance functional materials like gold thin films through precise control of electrical resistance based on

Nanostructured TiO₂-based gas sensors with enhanced sensitivity to reducing gases

• Wojciech Maziarz,
• Anna Kusior and
• Anita Trenczek-Zajac

Beilstein J. Nanotechnol. 2016, 7, 1718–1726, doi:10.3762/bjnano.7.164

• electrical resistance to occur, from the base resistance measured in air or gas (tres and trec, respectively) to 90% of stable signal after the gas or air introduction. On the other hand, the sensor response, S, was calculated as a ratio of resistance in air to resistance in gas: Results and Discussion The

• , respectively, are shown in Figure 4a,b. For both gases the sensor reacts with a large, stable and repeatable response, with step changes in the concentration range of 1.6–8.0 ppm for acetone and 80–400 ppm for nitric oxides. One can also see that there is a systematic decrease in the electrical resistance upon

• TiO2 nanostructures prepared via chemical oxidation before (a–c) and after (d,e) SnO2 deposition, and TiO2-based nanostructures prepared via thermal oxidation (f–h). Gas sensing characteristics for the T30 sensor: dynamic changes in the electrical resistance upon exposure to (a) 1.6–8.0 ppm acetone at

Thickness-modulated tungsten–carbon superconducting nanostructures grown by focused ion beam induced deposition for vortex pinning up to high magnetic fields

• Ismael García Serrano,
• Javier Sesé,
• Isabel Guillamón,
• Hermann Suderow,
• Sebastián Vieira,
• Manuel Ricardo Ibarra and
• José María De Teresa

Beilstein J. Nanotechnol. 2016, 7, 1698–1708, doi:10.3762/bjnano.7.162

• film starts the growth on a flat surface. In the final step, the linear Pt contacts are soldered to the Ti pads by the addition of thick, square, Pt deposits by FIBID. (a) Scheme of the experiment performed to measure the electrical resistance under perpendicular magnetic field. Due to the Lorentz

In situ characterization of hydrogen absorption in nanoporous palladium produced by dealloying

• Eva-Maria Steyskal,
• Christopher Wiednig,
• Norbert Enzinger and
• Roland Würschum

Beilstein J. Nanotechnol. 2016, 7, 1197–1201, doi:10.3762/bjnano.7.110

• dealloying, an electrochemical etching process that removes the less noble component from a master alloy. The volume and electrical resistance of np-Pd are investigated in situ upon electrochemical hydrogen loading and unloading. These properties clearly vary upon hydrogen ad- and absorption. During cyclic

• voltammetry in the hydrogen regime the electrical resistance changes reversibly by almost 10% upon absorbing approximately 5% H/Pd (atomic ratio). By suitable loading procedures, hydrogen concentrations up to almost 60% H/Pd were obtained, along with a sample thickness increase of about 5%. The observed

• electrochemical H absorption in an alkaline aqueous electrolyte. Volume and electrical resistance of the sample, two qualities both known to sensitively depend on the H content of Pd [7][8][4][9][10][11], are monitored in situ during electrochemical hydrogenation and compared to literature data. The Co–Pd master

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

• found by SEM imaging integrated in the FIB device (Zeiss NVision 40 SEM/FIB). The size of the chosen crystallite is critical as it directly determines the length of the FIB milled channel, and thus, the ratio between the electrical resistance originating from this channel and the feeding contacts. In

Evaluation of gas-sensing properties of ZnO nanostructures electrochemically doped with Au nanophases

• Elena Dilonardo,
• Michele Penza,
• Marco Alvisi,
• Cinzia Di Franco,
• Francesco Palmisano,
• Luisa Torsi and
• Nicola Cioffi

Beilstein J. Nanotechnol. 2016, 7, 22–31, doi:10.3762/bjnano.7.3

• strongly depends on MOS morphology and structure, and on the gaseous analyte [4]. The second function transduces the solid–gas interaction into the electrical resistance variation of the gas sensor, correlated to the adsorbed gas concentration to be detected; it is particularly influenced by the

• resistance between the values of steady-state of the electrical resistance of the sensor upon a target gas and in air, Rf and Ri, respectively. The mean gas sensitivity, Sm (% ppm−1), is defined as weighted mean of the ratio between percentage relative resistance change (%) over gas concentration unit (ppm

• paragraph. Gas-sensing properties In Figure 4A and Figure 4B, the time responses of the electrical resistance change of gas sensors based on pristine and Au-doped ZnO nanostructures annealed at 300 and 550 °C, respectively, are reported at different NO2 concentrations [0.5–10 ppm] and at an operating

Chemiresistive/SERS dual sensor based on densely packed gold nanoparticles

• Sanda Boca,
• Cosmin Leordean,
• Simion Astilean and
• Cosmin Farcau

Beilstein J. Nanotechnol. 2015, 6, 2498–2503, doi:10.3762/bjnano.6.259

• , 400084 Cluj-Napoca, Romania 10.3762/bjnano.6.259 Abstract Chemiresistors are a class of sensitive electrical devices capable of detecting (bio)chemicals by simply monitoring electrical resistance. Sensing based on surface enhanced Raman scattering (SERS) represents a radically different approach, in

• sensors are chemiresistors, which are sensitive electrical devices capable of detecting (bio)chemicals by simply monitoring electrical resistance. They require simple DC circuitry, and are therefore ideal for developing wearable/portable devices for protection from chemical exposure, or for environmental

• enhancement and the electrical resistance of the particle assembly. External molecular species adsorbed on the nanoparticles can modify the electrical response of the film, and can also be identified by their SERS spectrum (graphs and spectra are just for illustration). The advantages offered by such a dual

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

• nanorods occurs under the high fields and lower resistivity paths open through the ZnO nanoforest. Because of the geometrical nonuniformity of the ZnO nanoforest, the electrical resistance and electric field distribution between two probes are also nonuniform. Therefore, some segments along the current

Negative differential electrical resistance of a rotational organic nanomotor

• Hatef Sadeghi,
• Sara Sangtarash,
• Qusiy Al-Galiby,
• Rachel Sparks,
• Steven Bailey and
• Colin J. Lambert

Beilstein J. Nanotechnol. 2015, 6, 2332–2337, doi:10.3762/bjnano.6.240

Formation of pure Cu nanocrystals upon post-growth annealing of Cu–C material obtained from focused electron beam induced deposition: comparison of different methods

• Aleksandra Szkudlarek,
• Alfredo Rodrigues Vaz,
• Yucheng Zhang,
• Andrzej Rudkowski,
• Czesław Kapusta,
• Rolf Erni,
• Stanislav Moshkalev and
• Ivo Utke

Beilstein J. Nanotechnol. 2015, 6, 1508–1517, doi:10.3762/bjnano.6.156

• influence on the properties of the deposit structure, from small isolated nanocrystals of Cu (ca. 20 nm) at 25 °C towards continuous thin films of pure copper at 100 °C, using (hfac)CuVTMS [40]. In this paper we will show results obtained by SEM, TEM, and electrical resistance monitoring during post-growth

• formation of larger copper nanocrystals. Electrical measurements Figure 8 shows the typical behavior of a Cu–C FEBID line for a heating/cooling cycle. The as-deposited lines were non-conductive, showing an electrical resistance of few gigaohms at room temperature. After thermal annealing the resistance

Atomic force microscopy as analytical tool to study physico-mechanical properties of intestinal cells

• Christa Schimpel,
• Oliver Werzer,
• Eleonore Fröhlich,
• Gerd Leitinger,
• Markus Absenger-Novak,
• Birgit Teubl,
• Andreas Zimmer and
• Eva Roblegg

Beilstein J. Nanotechnol. 2015, 6, 1457–1466, doi:10.3762/bjnano.6.151

• the differentiation of M cells. Cell monolayer integrity and confluence were evaluated by measuring the transepithelial electrical resistance (TEER) with an Endohm culture cup connected to an epithelial volt ohm meter (World Precisions Instruments, Sarasota, USA). For AFM cell imaging/force

Tunable magnetism on the lateral mesoscale by post-processing of Co/Pt heterostructures

• Oleksandr V. Dobrovolskiy,
• Maksym Kompaniiets,
• Roland Sachser,
• Fabrizio Porrati,
• Christian Gspan,
• Harald Plank and
• Michael Huth

Beilstein J. Nanotechnol. 2015, 6, 1082–1090, doi:10.3762/bjnano.6.109

• elemental composition was quantified without thickness correction, so that the reported data are a qualitative indicator only. Electrical resistance measurements The electrical and magneto-resistance measurements were carried out in a helium-flow cryostat equipped with a superconducting solenoid. The

• profile the intensity from the Pt M edge (2.05 keV) and the Co K edge (6.92 keV) was used. Results and Discussion Structural and electrical resistance properties SEM images of the samples investigated in this work are shown in Figure 2, while their geometrical dimensions, elemental composition, and

• , though acquired with a statistical error of 3%, the EDX data in Table 1 only serve as an indicator of the Co/Pt ratio being crucial for the different Co/Pt alloy phase formation — an issue to which we return in what follows. The temperature dependence of the electrical resistance of all samples is

Morphology control of zinc oxide films via polysaccharide-mediated, low temperature, chemical bath deposition

• Florian Waltz,
• Hans-Christoph Schwarz,
• Andreas M. Schneider,
• Stefanie Eiden and
• Peter Behrens

Beilstein J. Nanotechnol. 2015, 6, 799–808, doi:10.3762/bjnano.6.83

• crystallites do not overlap very well after the first CBD growth step, the electrical conductivity is only moderate. The sheet resistance of the films after the first CBD is typically in the range of MΩ/sq. Therefore, an additional step is necessary to grow a dense, ZnO film in order to yield low electrical

• resistance for the final sample. Step 3: Second CBD The reaction conditions for the final growth step were adopted from Baxter and Schmuttenmaer, who obtained intergrown ZnO films after a reaction time of 3 h [48]. In our experiments, the reaction time could be reduced to 1 h due to the excellent growth

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

• -ultraviolet range. Results and Discussion The produced CNT-sponges are light and porous, and can be cut into pieces of the desired size as shown in Figure 1. The micro-porosity of the synthesized material is responsible for its very low density of about 15 mg/cm3 and its good conductivity (electrical

• resistance of about 40 Ω·cm−1). These values are comparable to those reported in the literature for similar samples [6]. Scanning electron microscopy (SEM) analysis of the interior of the samples reveals that the material is made of randomly self-assembled, long and interconnected tubular nanostructures

Room temperature, ppb-level NO₂ gas sensing of multiple-networked ZnSe nanowire sensors under UV illumination

• Sunghoon Park,
• Soohyun Kim,
• Wan In Lee,
• Kyoung-Kook Kim and
• Chongmu Lee

Beilstein J. Nanotechnol. 2014, 5, 1836–1841, doi:10.3762/bjnano.5.194

• constant flow rate of 200 cm3/min at 25 °C under 50% RH. The NO2 concentration was controlled by mixing NO2 gas with synthetic air at different ratios. The detailed procedures for the sensor fabrication and sensing test are reported elsewhere [32]. The electrical resistance of the gas sensors was

Growth evolution and phase transition from chalcocite to digenite in nanocrystalline copper sulfide: Morphological, optical and electrical properties

• Priscilla Vasthi Quintana-Ramirez,
• Ma. Concepción Arenas-Arrocena,
• José Santos-Cruz,
• Marina Vega-González,
• Omar Martínez-Alvarez,
• Víctor Manuel Castaño-Meneses,
• Laura Susana Acosta-Torres and
• Javier de la Fuente-Hernández

Beilstein J. Nanotechnol. 2014, 5, 1542–1552, doi:10.3762/bjnano.5.166

• structure. All CuxS products could be promising for optoelectronic applications. Keywords: abundant materials in the crust of Earth; electrical resistance; nanocrystals; nanodisks; non-toxic semiconductors; optical band gap; phase transition; photocurrent; Introduction Metallic chalcogenides based on

• sulfide with 2 and 1.8 of Cu/S ratio were synthesized successfully from chemical synthesis in an organic solvent at 220–260 °C. Amorphous CuxS was also obtained from aqueous solution at low temperatures with a low electrical resistance, indicative of a high conductivity. The evolution growth, formation of

• ), electrically by the four-points-probe technique, by UV–vis spectroscopy (Thermo Scientific Genesys 10S UV–vis spectrophotometer in the range of 200 to 1100 nm) in order to determine, the structural phase, the electrical resistance and optical absorbance spectra, respectively. The photoresponse measurements

Review of nanostructured devices for thermoelectric applications

• Giovanni Pennelli

Beilstein J. Nanotechnol. 2014, 5, 1268–1284, doi:10.3762/bjnano.5.141

• /∂x = εJ, it is possible to determine T(x) in the legs, and also ΦH and ΦC, so that an expression for the efficiency η can be obtained: where Rg and K are the total electrical resistance and the total thermal conductance of the generator, which can be evaluated respectively from the material

• ), where Stotal = Sp + | Sn |, and a series (parasitic) resistance RG. The current I depends on the generator electrical resistance Rg and on the load resistance RL. In the evaluation of these expressions, the variation with temperature of the thermoelectric parameters S, σ and kt, has been neglected

• operation of the device. This high reliability is due to the high level of interconnections (vertical and horizontal branches) of the net. It has been demonstrated [100] that the total top to bottom electrical resistance of the net increases only negligibly for a nanowire failure percentage up to 40%, that

Purification of ethanol for highly sensitive self-assembly experiments

• Kathrin Barbe,
• Martin Kind,
• Christian Pfeiffer and
• Andreas Terfort

Beilstein J. Nanotechnol. 2014, 5, 1254–1260, doi:10.3762/bjnano.5.139

• al. [29][32] show the highest sensitivity and accuracy. The latter sensor is based on the change of the electrical resistance of a very thin metal film upon adsorption as described by the Fuchs–Sondheimer theory [33][34]. Since this is a purely interfacial phenomenon, this kind of sensor is equally

Integration of ZnO and CuO nanowires into a thermoelectric module

• Dario Zappa,
• Simone Dalola,
• Guido Faglia,
• Elisabetta Comini,
• Matteo Ferroni,
• Caterina Soldano,
• Vittorio Ferrari and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2014, 5, 927–936, doi:10.3762/bjnano.5.106

• , with the overall effect of increasing the total electrical resistance of the device. A reduction in the nanowire length will increase the number of junctions that charge carriers have to face within the entire extension of the mat, thus increasing the total electrical resistance and reducing the

• approximately 4 mV/°C, confirming the correct behavior of the fabricated prototype planar thermoelectric device. The electrical resistance of the entire thermoelectric planar generation resulted about 9 MΩ. The overall performances of a thermoelectric generator can be evaluated by means of two parameters. The

• enhanced by improving electrical contact resistances; moreover, an increase in carrier concentration will boost the thermoelectric performance [34]. The main limitation of this prototype is to be found in the still high electrical resistance of the material, especially ZnO, limiting both the power factor

Gas sensing with gold-decorated vertically aligned carbon nanotubes

• Prasantha R. Mudimela,
• Mattia Scardamaglia,
• Oriol González-León,
• Nicolas Reckinger,
• Rony Snyders,
• Eduard Llobet,
• Carla Bittencourt and
• Jean-François Colomer

Beilstein J. Nanotechnol. 2014, 5, 910–918, doi:10.3762/bjnano.5.104

• very large surface area to volume ratio, high electron mobility, physico-chemical stability and high adsorption capability [2][3][4][5]. The use of CNTs as gas sensors was first proposed by Kong et al., who showed that a dramatic change in the electrical resistance of an individual single-walled

Analytical development and optimization of a graphene–solution interface capacitance model

• Hediyeh Karimi,
• Rasoul Rahmani,
• Reza Mashayekhi,
• Leyla Ranjbari,
• Amir H. Shirdel,
• Niloofar Haghighian,
• Parisa Movahedi,
• Moein Hadiyan and
• Razali Ismail

Beilstein J. Nanotechnol. 2014, 5, 603–609, doi:10.3762/bjnano.5.71

• the consideration just made, the equivalent circuit of the EGFET device is suggested in terms of a simple, well-defined theoretical model. It is seen that C′G is the capacitance that forms between the gate and the ionic liquid, RB is the electrical resistance of the solution, CG represents the

In situ monitoring magnetism and resistance of nanophase platinum upon electrochemical oxidation

• Eva-Maria Steyskal,
• Stefan Topolovec,
• Stephan Landgraf,
• Heinz Krenn and
• Roland Würschum

Beilstein J. Nanotechnol. 2013, 4, 394–399, doi:10.3762/bjnano.4.46

• gained by means of a direct comparison of the charge-induced response of two different properties, namely electrical resistance and magnetic moment. For this purpose, four-point resistance measurements and SQUID magnetometry were performed under identical in situ electrochemical control focussing on the

• regime of electrooxidation. Fully reversible variations of the electrical resistance and the magnetic moment of 6% and 1% were observed upon the formation or dissolution of a subatomic chemisorbed oxygen surface layer, respectively. The increase of the resistance, which is directly correlated to the

• due to spin–orbit coupling. Keywords: electrical resistance; electrochemistry; magnetism; porous nanocrystalline Pt; tunable properties; Introduction Porous nanophase materials with electrochemically induced tunability of properties [1] have become a topic of growing research interest in the past

Revealing thermal effects in the electronic transport through irradiated atomic metal point contacts

• Bastian Kopp,
• Zhiwei Yi,
• Daniel Benner,
• Fang-Qing Xie,
• Christian Obermair,
• Thomas Schimmel,
• Johannes Boneberg,
• Paul Leiderer and
• Elke Scheer

Beilstein J. Nanotechnol. 2012, 3, 703–711, doi:10.3762/bjnano.3.80

• seen in Figure 6, consist of an evaporated Au film with a thickness of 100 nm and width of 4 µm. The electrical resistance of these leads is several tens of ohms. Since the material is a pure metal, the resistance at 300 K varies roughly linearly with temperature. For a light-induced temperature change

Influence of the diameter of single-walled carbon nanotube bundles on the optoelectronic performance of dry-deposited thin films

• Kimmo Mustonen,
• Toma Susi,
• Antti Kaskela,
• Patrik Laiho,
• Ying Tian,
• Albert G. Nasibulin and
• Esko I. Kauppinen

Beilstein J. Nanotechnol. 2012, 3, 692–702, doi:10.3762/bjnano.3.79

• performance. Structural features such as SWCNT length, degree of bundling, and bundle length, diameter and orientation have received less attention, despite the fact that the electrical resistance of a SWCNT network is thought to be dominated by intertube and interbundle contact resistances [6][12

Functionalised zinc oxide nanowire gas sensors: Enhanced NO₂ gas sensor response by chemical modification of nanowire surfaces

• Eric R. Waclawik,
• Jin Chang,
• Andrea Ponzoni,
• Isabella Concina,
• Dario Zappa,
• Elisabetta Comini,
• Nunzio Motta,
• Guido Faglia and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2012, 3, 368–377, doi:10.3762/bjnano.3.43

• electrical resistance and conductance of the sample. Sensor response was measured at 190 °C operating temperature. We established through the TG measurements of functionalised ZnO samples, that the degradation of the organic capping layer of the nanowires and nanoparticles at this operating temperature was