Controlling surface morphology and sensitivity of granular and porous silver films for surface-enhanced Raman scattering, SERS

• Sherif Okeil and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2018, 9, 2813–2831, doi:10.3762/bjnano.9.263

• are observed due island formation during sputtering (Figure 1c,d) [77]. The granular morphology could be advantageous for the formation of hot spots resulting in an efficient SERS activity of the silver film. For the 200 nm thick silver film the coalescence of the adjacent silver clusters formed in

Comparative biological effects of spherical noble metal nanoparticles (Rh, Pd, Ag, Pt, Au) with 4–8 nm diameter

• Alexander Rostek,
• Marina Breisch,
• Kevin Pappert,
• Kateryna Loza,
• Marc Heggen,
• Manfred Köller,
• Christina Sengstock and
• Matthias Epple

Beilstein J. Nanotechnol. 2018, 9, 2763–2774, doi:10.3762/bjnano.9.258

• human cells [24][26][27], whereas in other studies, these effects were not observed [28][29][30]. With ultrasmall gold nanoparticles and gold clusters, different biological events are triggered that can lead to a higher cytotoxicity of very small particles (<3 nm) [31]. Very little is known about the

Size-selected Fe₃O₄–Au hybrid nanoparticles for improved magnetism-based theranostics

• Maria V. Efremova,
• Yulia A. Nalench,
• Eirini Myrovali,
• Anastasiia S. Garanina,
• Ivan S. Grebennikov,
• Polina K. Gifer,
• Maxim A. Abakumov,
• Marina Spasova,
• Makis Angelakeris,
• Alexander G. Savchenko,
• Michael Farle,
• Natalia L. Klyachko,
• Alexander G. Majouga and
• Ulf Wiedwald

Beilstein J. Nanotechnol. 2018, 9, 2684–2699, doi:10.3762/bjnano.9.251

• with the size of Fe3O4 NPs and clusters of NPs has been thoroughly discussed in the literature. See for example [57][58][59][60]. These aggregates can be considered as magnetic volumes in which the dipole–dipole interaction between NPs produces a strong magnetic field gradient leading to the

• predominant T2-effect. The r2-relaxivity is affected by NP aggregation, and three different regimes can be distinguished. First, for small clusters, r2 is given by the theory of the outer sphere. NPs are homogeneously dispersed, and water protons diffuse between the magnetic cores before becoming completely

• are in the MAR where the diffusion processes are the predominant factor for the r2-relaxivity. This limit correlates well with the model predictions for the r2 value described in [66] considering clusters of 4–5 NPs in the case of sample MNP-6 (modeled r2 = 154 mM−1·s−1) and single NPs of MNP-15

Enhancement of X-ray emission from nanocolloidal gold suspensions under double-pulse excitation

• Wei-Hung Hsu,
• Frances Camille P. Masim,
• Armandas Balčytis,
• Hsin-Hui Huang,
• Tetsu Yonezawa,
• Aleksandr A. Kuchmizhak,
• Saulius Juodkazis and
• Koji Hatanaka

Beilstein J. Nanotechnol. 2018, 9, 2609–2617, doi:10.3762/bjnano.9.242

• assume that under our experimental conditions the fragmentation threshold will be easily reached resulting in breaking up of the gold nanoparticles into smaller clusters. Fragmentation can proceed via explosive ablation at the characteristic time scales from few tens to few hundred of picoseconds [12][42

• -laser pulses for terahertz-wave emission from water flow were reported [51], while terahertz emission from various solutions under broad focusing was already known [52]. Simultaneous emission of X-ray and terahertz waves from gas clusters in vacuum [53][54], Al-coated glass substrates in vacuum [54], or

Au–Si plasmonic platforms: synthesis, structure and FDTD simulations

• Anna Gapska,
• Marcin Łapiński,
• Paweł Syty,
• Wojciech Sadowski,
• Józef E. Sienkiewicz and
• Barbara Kościelska

Beilstein J. Nanotechnol. 2018, 9, 2599–2608, doi:10.3762/bjnano.9.241

• 4f7/2 and 4f5/2 excitations differs from the statistical ratio of 4:3 and the linewidths (FWHM) are not equal. The size of the clusters can also affect the symmetry of the Au 4f7/2 peak on the side of higher binding energies, and the asymmetry increases with decreasing cluster size. In our

High-temperature magnetism and microstructure of a semiconducting ferromagnetic (GaSb)_1−x(MnSb)_x alloy

• Leonid N. Oveshnikov,
• Elena I. Nekhaeva,
• Alexey V. Kochura,
• Alexander B. Davydov,
• Mikhail A. Shakhov,
• Sergey F. Marenkin,
• Oleg A. Novodvorskii,
• Alexander P. Kuzmenko,
• Alexander L. Vasiliev,
• Boris A. Aronzon and
• Erkki Lahderanta

Beilstein J. Nanotechnol. 2018, 9, 2457–2465, doi:10.3762/bjnano.9.230

• was suggested [9] that the ferromagnetic ordering in this case is induced by the interaction of MnSb magnetic clusters with carriers inside the matrix. It should induce carrier spin-polarization and lead to the formation of a long-range ferromagnetic percolation cluster, which includes both MnSb

• magnetic clusters and spin-polarized carriers. However, to verify this assumption and to reveal the origin of the high-temperature ferromagnetism in GaSb–MnSb alloys, one needs a detailed knowledge of the sample structure. Thus, in this paper we investigate magnetic and transport properties of the GaSb

Performance analysis of rigorous coupled-wave analysis and its integration in a coupled modeling approach for optical simulation of complete heterojunction silicon solar cells

• Ziga Lokar,
• Benjamin Lipovsek,
• Marko Topic and
• Janez Krc

Beilstein J. Nanotechnol. 2018, 9, 2315–2329, doi:10.3762/bjnano.9.216

• rear textures) would need a large number of sublayers and modes. Faster computers or clusters would enable simulation of structures larger than those presented, but still, it needs to be emphasized that doubling of both the total modes and sublayers requires a computer approximately ten times faster to

Surface energy of nanoparticles – influence of particle size and structure

• Dieter Vollath,
• Franz Dieter Fischer and
• David Holec

Beilstein J. Nanotechnol. 2018, 9, 2265–2276, doi:10.3762/bjnano.9.211

• magic number for clusters consisting of 55 atoms. More detailed insight is provided by a thorough ab initio study analyzing the Au55 cluster performed by Holec et al. [53] and Vollath et al. [14]. These studies established the fact that the most stable state of this cluster is glassy. The accompanying

• (shaded area) results of Castro et al., the result of Cluskey et al., obtained on Au55 clusters, is also located. Visualization of the setting for the estimation the number of next neighbors (coordination number) of an atom at the surface of a spherical particle with diameter d = 2R. The volume of the

Intrinsic ultrasmall nanoscale silicon turns n-/p-type with SiO₂/Si₃N₄-coating

• Dirk König,
• Daniel Hiller,
• Noël Wilck,
• Birger Berghoff,
• Merlin Müller,
• Sangeeta Thakur,
• Giovanni Di Santo,
• Luca Petaccia,
• Joachim Mayer,
• Sean Smith and
• Joachim Knoch

Beilstein J. Nanotechnol. 2018, 9, 2255–2264, doi:10.3762/bjnano.9.210

• approximant; one NC is embedded in SiO2 and one NC resides in Si3N4 (Figure 1). We found earlier that – regarding DFT – Si10-NCs are the smallest NCs above the atomic limit below which Si-clusters behave as small molecules in the gas phase [13]. The frontier-OMOs exist within the Si3N4-embedded Si-NC (Figure

The role of adatoms in chloride-activated colloidal silver nanoparticles for surface-enhanced Raman scattering enhancement

• Nicolae Leopold,
• Andrei Stefancu,
• Krisztian Herman,
• István Sz. Tódor,
• Stefania D. Iancu,
• Vlad Moisoiu and
• Loredana F. Leopold

Beilstein J. Nanotechnol. 2018, 9, 2236–2247, doi:10.3762/bjnano.9.208

• sodium chloride in the reacting solution. During the photoreduction process, the surface of the AgCl particles becomes covered with clusters of Ag atoms, which was also reported by Wang et al. [27]. The silver atom clusters grow continuously during light exposure, leading to the formation of AgNPs on the

Electrospun one-dimensional nanostructures: a new horizon for gas sensing materials

• Muhammad Imran,
• Nunzio Motta and
• Mahnaz Shafiei

Beilstein J. Nanotechnol. 2018, 9, 2128–2170, doi:10.3762/bjnano.9.202

The structural and chemical basis of temporary adhesion in the sea star Asterina gibbosa

• Birgit Lengerer,
• Marie Bonneel,
• Mathilde Lefevre,
• Elise Hennebert,
• Philippe Leclère,
• Emmanuel Gosselin,
• Peter Ladurner and
• Patrick Flammang

Beilstein J. Nanotechnol. 2018, 9, 2071–2086, doi:10.3762/bjnano.9.196

• of A. gibbosa was slightly broader than the flexible stem and full of collagenous fibres (Figure 2B). The collagen fibres were arranged in thick bundles and alternated with clusters of secretory gland cells (Figure 2B and Figure 3A). In asteroids, three tube foot morphotypes have been described – i.e

Metal-free catalysis based on nitrogen-doped carbon nanomaterials: a photoelectron spectroscopy point of view

• Mattia Scardamaglia and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2018, 9, 2015–2031, doi:10.3762/bjnano.9.191

• . Indeed, the graphitic network can be easily modified by the introduction of heteroatoms, functional groups or defects, such as dislocations, vacancies or edges [25][34][35]. They act as active sites for electron localization or they are useful to anchor metal clusters or foreign molecules that will, in

Recent highlights in nanoscale and mesoscale friction

• Andrea Vanossi,
• Dirk Dietzel,
• Andre Schirmeisen,
• Ernst Meyer,
• Rémy Pawlak,
• Thilo Glatzel,
• Marcin Kisiel,
• Shigeki Kawai and
• Nicola Manini

Beilstein J. Nanotechnol. 2018, 9, 1995–2014, doi:10.3762/bjnano.9.190

• particles can be of importance. This was demonstrated by MD simulations for gold clusters on HOPG, where a significant reduction of static friction was found by simply increasing the cluster thickness. As a result, the nanostructure becomes elastically stiffer, which goes along with a reduced tendency to

• heterogeneous contacts formed between hexagonal boron nitride clusters and graphene, a recent study has pointed out how kinetic friction can drastically decrease when the slider enters a regime of soliton-supported smooth sliding beyond a certain contact area [79]. Confined systems and lubrication Several

Synthesis of carbon nanowalls from a single-source metal-organic precursor

• André Giese,
• Sebastian Schipporeit,
• Volker Buck and
• Nicolas Wöhrl

Beilstein J. Nanotechnol. 2018, 9, 1895–1905, doi:10.3762/bjnano.9.181

• found nanocrystalline Al3C4 clusters by TEM measurements in our CNWs that were measured to be of 30 nm in size [23]. In addition to the AES measurements, EDX measurements were carried out on the CNWs to identify additional trace elements in the carbon structures (Figure 11). Besides the already measured

• carbon, aluminium, chromium and iron from the stainless steel substrate, and oxygen can be identified. The oxygen is likely from the metal-organic precursor, which also contains oxygen. Thus, in addition to the Al3C4 clusters, also Al2O3 compounds in the films are possible, also H2O adsorption cannot be

Synthesis of rare-earth metal and rare-earth metal-fluoride nanoparticles in ionic liquids and propylene carbonate

• Marvin Siebels,
• Lukas Mai,
• Laura Schmolke,
• Kai Schütte,
• Juri Barthel,
• Junpei Yue,
• Jörg Thomas,
• Bernd M. Smarsly,
• Anjana Devi,
• Roland A. Fischer and
• Christoph Janiak

Beilstein J. Nanotechnol. 2018, 9, 1881–1894, doi:10.3762/bjnano.9.180

• to ion chromatographic (IC) analysis, a fluoride source other than the [BF]− anion can be excluded since the IL contains only a very small amount of fluoride ions (below 1 ppm, see Experimental section for IC analysis conditions) [44][45]. Alternatively, reactive metal atoms or metal clusters may

Synthesis of hafnium nanoparticles and hafnium nanoparticle films by gas condensation and energetic deposition

• Irini Michelakaki,
• Nikos Boukos,
• Dimitrios A. Dragatogiannis,
• Spyros Stathopoulos,
• Costas A. Charitidis and
• Dimitris Tsoukalas

Beilstein J. Nanotechnol. 2018, 9, 1868–1880, doi:10.3762/bjnano.9.179

• the cohesive energy of Hf (6.31 eV/atom [55]), it is quite improbable that all clusters collide with each other to be completely fragmented. Even if a minority of multi-charged NPs (doubly/triply charged) exists and the maximum substrate voltage Vs = 4.5 kV is applied, the energy per atom will still

• target (99.95%). Due to collisions with Ar gas, cooling of the sputtered metal atoms takes place, leading to a supersaturated metal atom vapor. Collisions between the cooled metal atoms lead to nucleation and growth of initial clusters. Collisions between these initial cluster ‘seeds’ followed by

• . This observation suggests that the polymer matrix has undergone a change during energetic deposition of nanoparticles. A possible explanation is that the clusters locally heat the PMMA above glass transition temperature, which results in their immersion into the polymer matrix forming a metal–polymer

Direct AFM-based nanoscale mapping and tomography of open-circuit voltages for photovoltaics

• Katherine Atamanuk,
• Justin Luria and
• Bryan D. Huey

Beilstein J. Nanotechnol. 2018, 9, 1802–1808, doi:10.3762/bjnano.9.171

• after the initial local planarization (Figure 3a, smooth central area). A corner of this region is depicted in the higher-magnification SEM micrograph (Figure 3b), which also follows ca. 10 nanomilling steps within the square dashed overlay. The sparse bright features around the milled area are clusters

Cryochemical synthesis of ultrasmall, highly crystalline, nanostructured metal oxides and salts

• Elena A. Trusova and
• Nikolai S. Trutnev

Beilstein J. Nanotechnol. 2018, 9, 1755–1763, doi:10.3762/bjnano.9.166

• predetermined size that are several nanometers in diameter in the form of clusters or crystallites with an almost ideal lattice. It has been shown that when a colloid undergoes nitrogen cryotreatment, the formed nanoparticles, having a high surface energy, are characterized by a low degree of aggregation due to

Nanoscale electrochemical response of lithium-ion cathodes: a combined study using C-AFM and SIMS

• Jonathan Op de Beeck,
• Nouha Labyedh,
• Alfonso Sepúlveda,
• Valentina Spampinato,
• Alexis Franquet,
• Thierry Conard,
• Philippe M. Vereecken,
• Wilfried Vandervorst and
• Umberto Celano

Beilstein J. Nanotechnol. 2018, 9, 1623–1628, doi:10.3762/bjnano.9.154

• results show that highly lithiated domains are localized within sub-micrometer clusters, which also represent a low-resistance path for the electronic current in the cathode layer. It is worth noting that besides the regions with a clear electrical and chemical correlation, conductive spots without high

Nanocomposites comprised of homogeneously dispersed magnetic iron-oxide nanoparticles and poly(methyl methacrylate)

• Sašo Gyergyek,
• David Pahovnik,
• Ema Žagar,
• Alenka Mertelj,
• Rok Kostanjšek,
• Miloš Beković,
• Marko Jagodič,
• Heinrich Hofmann and
• Darko Makovec

Beilstein J. Nanotechnol. 2018, 9, 1613–1622, doi:10.3762/bjnano.9.153

• dispersed as clusters; however, single nanoparticles were clearly visible (Figure 4a). The dispersion of the nanoparticles in the PMMA matrix was even more uniform as the amount of nanoparticles was increased to 52 wt % in the case of the NC-3 sample (Figure 4b). The glass-transition temperature (Tg) was

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

• , whereas clusters of more than three particles are visible at 10 mM (inset of Figure 2e). The same study was repeated using an increased particle concentration in the solutions (sample , , and ) but the obtained substrate coverage was apparently not significantly affected, at least in the investigated

Formation and development of nanometer-sized cybotactic clusters in bent-core nematic liquid crystalline compounds

• Yuri P. Panarin,
• Sithara P. Sreenilayam,
• Jagdish K. Vij,
• Anne Lehmann and
• Carsten Tschierske

Beilstein J. Nanotechnol. 2018, 9, 1288–1296, doi:10.3762/bjnano.9.121

• compounds, two relaxation processes are identified and assigned to (i) collective dynamics of molecules in nanometer-sized cybotactic clusters and (ii) individual molecular relaxations, in the ascending order of frequency of the probe field. The temperature and the bias electric field dependence of the

• function of temperature and the bias field. Keywords: bent-core liquid crystals; biaxiality; clusters; dielectric spectroscopy; Introduction Biaxial liquid crystals (LCs) exhibit supramolecular structures with long-range orientational ordering of the long and the short molecular axes but without a long

• characteristics of the nematic phase of the bent-core LCs arise from so-called cybotactic clusters (with partial smectic order) [30][31] and hence detailed investigations of clusters and reasons for their presence in nematic phase are essential for answering the pending questions. For example, the spontaneous

Atomistic modeling of tribological properties of Pd and Al nanoparticles on a graphene surface

• Alexei Khomenko,
• Miroslav Zakharov,
• Denis Boyko and
• Bo N. J. Persson

Beilstein J. Nanotechnol. 2018, 9, 1239–1246, doi:10.3762/bjnano.9.115

• the metallic clusters is much stronger (in particular for the Pd cluster) than the interaction potential between a metal atom and the graphene carbon atoms, it is likely that the ordered domains of metal atoms are not commensurate with the graphene lattice at any point during slip. Nevertheless

Comparative study of antibacterial properties of polystyrene films with TiO_x and Cu nanoparticles fabricated using cluster beam technique

• Vladimir N. Popok,
• Cesarino M. Jeppesen,
• Peter Fojan,
• Anna Kuzminova,
• Jan Hanuš and
• Ondřej Kylián

Beilstein J. Nanotechnol. 2018, 9, 861–869, doi:10.3762/bjnano.9.80

• formed in a cluster source into polymer simultaneously synthesized by plasma-enhanced chemical vapour deposition, by coating the NPs with a thin overlay or by soft landing of clusters on ex situ fabricated films followed by thermal annealing facilitating the partial embedding of clusters into the polymer

• [9][10][11][12][13][14][15]. In the current work, both Ti and Cu clusters are produced using magnetron sputtering in special cluster sources and deposited on substrates coated by a thin layer of polystyrene (PS). The focus is on the optimization of the nanocomposite formation using the cluster beam

• technique and the material properties as well as on the comparison of bactericidal efficiency of the prepared composites with either TiOx or Cu NPs against E.coli bacteria as a model microorganism. Results and Discussion Morphology and composition of deposited clusters Copper cluster are deposited from the