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

• continuous amorphous layer. Then, we compare electrical parameters measured by conventional Hall effect with the evolution of the crystal structure imaged by TEM as functions of the laser energy densities. The TEM analysis (Figure S11, Supporting Information File 1) shows that for energies of 0.74 and 0.76 J

• melt the surface. In contrast, following a LTA at 0.79 J·cm−2 the SiGe top layer is completely amorphous, clearly indicating that in this case the whole SiGe layer was molten, leaving no seed for a perfect recrystallization. The threshold energy for surface melt is therefore located between 0.76 and

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

• amorphous carbon. Combining the two values one can deduce that the synthesized material is almost entirely sp2-bonded nanocrystalline graphite with almost no carbon being sp3-bonded. The heights of the CNWs were also obtained from the cross-sectional SEM pictures in Figure 3 and Figure 4 and plotted in a

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

• corresponding to the (10−10) crystal planes of hexagonal close-packed (hcp) Hf (Figure 2, regions A, JCPDS 00-038-1478). In the shell, the coexistence of nanocrystallites of orthorhombic HfO2 (Figure 2, regions with arrows) within amorphous regions is observed. The distance between adjacent planes in the shell

• boundaries, where a broad spectrum of interatomic distances exist. The resulting X-ray diffraction pattern appears very similar to that of an amorphous material. Additionally, from the X-ray patterns, it is observed that the relative intensity of the peaks HfO2 and Hf IHfO2/IHf decreases with increasing the

• composed of orthorhombic HfO2 nanocrystallites indicated by arrows exhibiting lattice fringes of d = 0.295 nm corresponding to (101) HfO2 embedded in an amorphous layer. X-ray pattern of hafnium NPs on Si substrate synthesized for different aggregation-zone lengths D = 50, 75 and 100 nm. a) Bright-field

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

• of the sp2 carbon atoms in amorphous and graphitic carbon, respectively [22][37]. The intensity ratio of ID/IG (I represents the intensity of the D and G peaks) for the hexagonal magnetic mesoporous sample NPLs-2.5-800 is determined to be 1.02, indicating most of the carbon is amorphous in structure

Increasing the performance of a superconducting spin valve using a Heusler alloy

• Andrey A. Kamashev,
• Aidar A. Validov,
• Joachim Schumann,
• Vladislav Kataev,
• Bernd Büchner,
• Yakov V. Fominov and
• Ilgiz A. Garifullin

Beilstein J. Nanotechnol. 2018, 9, 1764–1769, doi:10.3762/bjnano.9.167

• this respect it would be very interesting to explore theoretically and experimentally the option of optimization of the F1 layer in the SSV AFM/F1/N1/F2/N2/S heterostructure. Recently, Singh et al. [32] reported a huge SSV effect for a S/F1/N/F2 structure made of amorphous MoGe, Ni, Cu and CrO2 as S

Controllable one-pot synthesis of uniform colloidal TiO₂ particles in a mixed solvent solution for photocatalysis

• Jong Tae Moon,
• Seung Ki Lee and
• Ji Bong Joo

Beilstein J. Nanotechnol. 2018, 9, 1715–1727, doi:10.3762/bjnano.9.163

• particles. When uniform, amorphous TiO2 particles were calcined at an optimal temperature (500 °C), the final sample exhibited beneficial characteristics such as high anatase crystallinity with a mixed phase of anatase and rutile and relatively high surface area. The photocatalytic efficiency of the uniform

• TiO2 precursor. Specifically, a typical synthesis involves three steps, as illustrated in Scheme 1: 1) the formation of TiO2 nucleates and subsequent growth of amorphous TiO2 spheres by a sol–gel reaction of titanium butoxide (TBOT) in the mixed solvent with hydroxypropylcellulose (HPC) as a surfactant

• ; 2) aging step of the spherical TiO2 particles in the water-containing solvent to make the surface of TiO2 particles condensed; and 3) calcination to crystallize amorphous TiO2 particles into their crystallized counterparts. The hydrolysis and condensation of the TBOT precursor are highly influenced

Friction force microscopy of tribochemistry and interfacial ageing for the SiO_x/Si/Au system

• Christiane Petzold,
• Marcus Koch and
• Roland Bennewitz

Beilstein J. Nanotechnol. 2018, 9, 1647–1658, doi:10.3762/bjnano.9.157

• Au layer, while no adhesive Cr layer could be distinguished between Si and Au. An amorphous layer (marked with asterisk in Figure 7) with a thickness of about 13 nm covers the surface that had been in sliding contact with Au(111). A rather sharp border marks the transition from amorphous Si to

• crystalline Si (Figure 7d). If the amorphous layer contained significant amounts of oxygen, it would appear brighter than the crystalline silicon. This was not the case and we conclude that the amorphization is a mechanical process that does not require oxidation to occur. Fourier transformation of the images

• (right side of Figure 7) revealed crystalline order for the tip material lattice and amorphous short-range structure for the layer that was transformed by the sliding contact. Discussion We start by discussing the absence of contact ageing in our slide–hold–slide experiments by AFM in ultrahigh vacuum

Sulfur-, nitrogen- and platinum-doped titania thin films with high catalytic efficiency under visible-light illumination

• Boštjan Žener,
• Lev Matoh,
• Giorgio Carraro,
• Bojan Miljević and
• Romana Cerc Korošec

Beilstein J. Nanotechnol. 2018, 9, 1629–1640, doi:10.3762/bjnano.9.155

• determine the crystallization temperature of different xerogel samples and the course of their thermal decomposition. The thermal decomposition of the amorphous xerogels, followed by the complementary techniques of thermal analysis of different samples are shown in Figure 1. The thermal decomposition of

• at different thermal treatment temperatures. At 450 and 500 °C, the sample has not yet crystallized (amorphous phase present). The sample starts crystallizing at 550 °C (crystallite size 9 nm). With increasing thermal treatment temperature, the crystallite size also increases (11 nm at 600 °C and 14

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

• putty that hardens at body temperature [14]. Typically, the liquid component is (MMA) and the powder component is a polymer with additives that enable rapid hardening at body temperature [14]. One of such polymers is poly(methyl methacrylate) (PMMA). It is an amorphous, linear thermoplastic having good

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

• . Measurements of the interfacial contact angle were made on the as-fabricated amorphous membrane and after pore widening with a range of pore diameters from 25 to 100 nm. The possible applications of PAMs for various membrane technologies is shown. Keywords: interfacial contact angle; membranes; porous anodic

• contact angle, another highly influential factor is exerted by the physicochemical properties of a PAM surface, or as it is often called, the “surface chemistry”. In this study we did not change this factor so as to specify the intrinsic properties of the as-made amorphous membrane’s influence on the

• . The black dotted lines are polynomial fits shown as a guide to the eye for selected data sets. Physical characteristics (average values) of the experimental samples (before etching, as-produced amorphous membrane). Contact angle values for as-made PAMs obtained in 0.3 M oxalic acid (type I and type II

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

• or nitride, amorphous, nanocrystalline or crystalline) anisotropically on the nanoscale using a commercial setup (OXFORD PlasmaLab 80 Plus ICP65, England), compare Figure 1c in [41]. To generate high-aspect-ratio nanopillars, in the first step the sacrificial SiOx layer is completely removed together

• amorphous Si or SiN as a sacrificial layer. The size distributions of the opened SiN disks are similar to those of the Au NPs. The membranes are etched with a commercial RIE etcher at RT (cf. Figure 1f, for further details see Supporting Information File 1). The cross section of a nanopore of comparable

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

• peaks of radial distribution function are blurred indicating that the nanoparticles are amorphous or polycrystalline. Keywords: aluminum; friction force; graphene; nanoparticle; nanotribology; palladium; Introduction The study of surface or interface phenomena at the atomic level has attracted

• disordered structure. After cooling, some ordering occurs resulting in a higher first peak in the RDF, which is located at the nearest-neighbor distance in the bulk state (2.863 Å for Al and 2.729 Å for Pd). Nonetheless, the peaks are much broader than for the ideal bulk crystal, indicating amorphous or

• ]. The peaks of RDF are blurred and we can conclude that long-range atomic order is absent and the nanoparticles are amorphous or have a polycrystalline order. We have observed regions of local order of atoms on the particle bottom surface, which may influence the saw-like form of the substrate force as

A novel copper precursor for electron beam induced deposition

• Caspar Haverkamp,
• George Sarau,
• Mikhail N. Polyakov,
• Ivo Utke,
• Marcos V. Puydinger dos Santos,
• Silke Christiansen and
• Katja Höflich

Beilstein J. Nanotechnol. 2018, 9, 1220–1227, doi:10.3762/bjnano.9.113

• . Optical transmission/reflection measurements of deposited pads showed a dielectric behavior of the material in the optical spectral range. The general behavior of the permittivity could be described by applying the Maxwell–Garnett mixing model to amorphous carbon and copper. The dielectric function

• FEBID pads. The Raman spectrum in Figure 2a of the precursor shows a complex structure with a number of distinct peaks. Under the impact of the electron beam the spectrum changes to a broad Raman response (black curve in Figure 2a) that is typical for amorphous materials. The different features of the

• carbon, as well as the G-peak position of 1580 cm−1, indicates a highly amorphous carbon structure inside the deposit [19]. The determination of reliable values for the optical response of FEBID materials is difficult due to the long deposition times for large areas. This makes standard measurements like

Room-temperature single-photon emitters in titanium dioxide optical defects

• Kelvin Chung,
• Yu H. Leung,
• Chap H. To,
• Aleksandra B. Djurišić and
• Snjezana Tomljenovic-Hanic

Beilstein J. Nanotechnol. 2018, 9, 1085–1094, doi:10.3762/bjnano.9.100

• Corporation). Thin films annealed at various temperatures, NA-TiO2, a-450 °C-TiO2, b-450 °C-TiO2 and 850 °C-TiO2, were investigated. The expected TiO2 phases were an amorphous phase in the untreated sample, anatase in a-450 °C-TiO2 and rutile in 850 °C-TiO2 [57]. The confocal scans in Figure 2a–d show

Review on nanoparticles and nanostructured materials: history, sources, toxicity and regulations

• Jaison Jeevanandam,
• Ahmed Barhoum,
• Yen S. Chan,
• Alain Dufresne and
• Michael K. Danquah

Beilstein J. Nanotechnol. 2018, 9, 1050–1074, doi:10.3762/bjnano.9.98

• form of nanometer-sized cellulosic-fibrils are 100–1000 nm long, containing both crystalline and amorphous segments. The unique strength and extreme performance properties of various natural fibers such as wood are attributed to their elementary hierarchical structure with nanofibrillar components [187

• and protein that are aligned in a column and layers of calcite, forms the thin and strong eggshell. During the eggshell formation, the CaCO3 NPs begin as an amorphous mineral which is transformed by the c-type lectin proteins into ordered crystals. The crystal transformation is initiated by the

Magnetic characterization of cobalt nanowires and square nanorings fabricated by focused electron beam induced deposition

• Federico Venturi,
• Gian Carlo Gazzadi,
• Amir H. Tavabi,
• Alberto Rota,
• Rafal E. Dunin-Borkowski and
• Stefano Frabboni

Beilstein J. Nanotechnol. 2018, 9, 1040–1049, doi:10.3762/bjnano.9.97

• subsequent passes was negligible. This fabrication approach could lead to local small thickness inhomogeneities in areas where the rectangles overlap. The amorphous C and Si substrates were used for TEM and MFM studies, respectively. All depositions and analyses were carried out at room temperature. Although

• performed on as-deposited samples without applying an external magnetic field. Two different sets of NWs on amorphous C substrates were studied: one deposited at a beam energy of 15 keV and another deposited at a beam energy of 5 keV. In each sample, the deposited shape was the same: 2.5 µm in length, 50 nm

• square nanorings Two square nanorings, each composed of four NWs, were deposited on amorphous C and studied using L-TEM. The first nanoring was deposited at 5 keV. Each NW was deposited by scanning the beam for 50 s on a 1 × 0.05 μm2 area, resulting in sides that are 1 μm long and ca. 100 nm wide. When

Electro-optical interfacial effects on a graphene/π-conjugated organic semiconductor hybrid system

• Karolline A. S. Araujo,
• Luiz A. Cury,
• Matheus J. S. Matos,
• Thales F. D. Fernandes,
• Luiz G. Cançado and
• Bernardo R. A. Neves

Beilstein J. Nanotechnol. 2018, 9, 963–974, doi:10.3762/bjnano.9.90

• microplates were tested (see Experimental section for a definition of graphite microplates). Several attempts with mica and SiOx yielded amorphous 3D-like RA agglomerates only (Figure S1, Supporting Information File 1). However, the graphene-RA interface in graphite microplate substrates systematically

• coated using a 2 mM RA solution, producing a multilayered RA sample as shown in Figure 3a. The substrate surface is partially covered by a thick and amorphous RA layer (thickness ranges from 2 nm up to ≈10 nm), which reveals no molecular order in high-resolution AFM images (data not shown), in contrast

• exactly the case for the amorphous multilayered RA sample. However, in the RA monolayer case, the phenomenology is different. As previous works have demonstrated, structural organization in π-conjugated polymer films can improve their electrical [3][31][32] and optical [30][32][33] properties. The

A review of carbon-based and non-carbon-based catalyst supports for the selective catalytic reduction of nitric oxide

• Shahreen Binti Izwan Anthonysamy,
• Syahidah Binti Afandi,
• Mehrnoush Khavarian and
• Abdul Rahman Bin Mohamed

Beilstein J. Nanotechnol. 2018, 9, 740–761, doi:10.3762/bjnano.9.68

• process is also important for the purification of pristine CNTs from amorphous carbon, fullerenes, coal, and catalyst particles by means of their production. The wet chemical method is considered to be one of the most efficient methods for purification, activation, and functionalisation of CNTs. In this

• the NO removal activity. 0.5 Mn/(Mn + Ce) molar ratio was found to be the optimum loading amount for Mn–CeOx/CNT catalyst preparation. From the HRTEM images, an uneven shape and fuzzy crystal lattice was identified on the metal nanoflakes suggesting that the Mn–CeOx/CNT catalyst is amorphous in

• structure. The XRD result confirms only the presence of typical CNT peaks. Both of these features highly contribute towards high NO activity at low SCR temperature. This conclusion is in agreement with the research work of Tang et al. [84], where amorphous oxides showed greater NO activity compared to

Cyclodextrin-assisted synthesis of tailored mesoporous silica nanoparticles

• Fuat Topuz and
• Tamer Uyar

Beilstein J. Nanotechnol. 2018, 9, 693–703, doi:10.3762/bjnano.9.64

• content was sufficiently high to generate stable particles without any aggregation. In the following step, hydroxypropyl-functionalized CDs (i.e., HP-γ-CDs) were used in the preparation of silica particles. Unlike β-CDs, HP-CDs are amorphous, and do not show any crystalline phases owing to

• with the CD-type used. β-CD moieties are highly crystalline compounds and form ordered multimolecular structures, while HP-γ-CD has amorphous characteristics with different aggregation behavior (Figure S5, Supporting Information File 1). Therefore, the shifts in the WAXS patterns could be attributed to

Anchoring Fe₃O₄ nanoparticles in a reduced graphene oxide aerogel matrix via polydopamine coating

• Błażej Scheibe,
• Radosław Mrówczyński,
• Natalia Michalak,
• Karol Załęski,
• Michał Matczak,
• Mateusz Kempiński,
• Zuzanna Pietralik,
• Mikołaj Lewandowski,
• Stefan Jurga and
• Feliks Stobiecki

Beilstein J. Nanotechnol. 2018, 9, 591–601, doi:10.3762/bjnano.9.55

• material is an amorphous carbon. However, the use of other excitation energies leads to completely different conclusions. The calculated ID/IG ratios and mean defect distance (LD) together with full-widths-at-half-maximum (FWHM) of D and G peaks of rGO-based aerogels probed with different laser sources are

• nanoparticles at the GO defect sites. In addition, PDA coating does not affect the magnetic properties of the iron oxide-modified rGO aerogel. It is believed that introduction of amorphous carbon-coated functional additives (core-shell structures) improves a reduced graphene oxide aerogel lattice, anchor

Single-step process to improve the mechanical properties of carbon nanotube yarn

• Maria Cecilia Evora,
• Xinyi Lu,
• Nitilaksha Hiremath,
• Nam-Goo Kang,
• Kunlun Hong,
• Roberto Uribe,
• Gajanan Bhat and
• Jimmy Mays

Beilstein J. Nanotechnol. 2018, 9, 545–554, doi:10.3762/bjnano.9.52

• due to the presence of amorphous carbon. Carbon atoms can be sputtered from the outer shell under irradiation and recombine. Fitting of all spectra was achieved with Lorentzian peaks and the ID/IG ratio was calculated for each sample. ID/IG increases with an increase in the number of defects on the

Kinetics of solvent supported tubule formation of Lotus (Nelumbo nucifera) wax on highly oriented pyrolytic graphite (HOPG) investigated by atomic force microscopy

• Sujit Kumar Dora,
• Kerstin Koch,
• Wilhelm Barthlott and
• Klaus Wandelt

Beilstein J. Nanotechnol. 2018, 9, 468–481, doi:10.3762/bjnano.9.45

• HOPG (nonpolar, crystalline) and horizontally oriented tubules on glass (polar, amorphous). They also found that pure nonacosan-10-ol does not form tubules, but that an admixture of 3-4% of corresponding diols is needed for tubules to form. In addition, they also portrayed the effect of chirality by

• structure of the wax objects, namely, tubules. On the other hand it remains unclear as to why they have a certain orientation, namely dominantly upright to the substrate surface, independent of the nominal thickness of an instantaneously solidified and therefore supposedly amorphous wax film, which, in turn

• , must be the reservoir for the following tubules' growth. One possibility would be a recrystallization of the initially formed amorphous film over time (Ensikat et al. have demonstrated a crystalline nature of wax deposits grown from wax material isolated from plants [34]) thus providing a template for

Influence of the preparation method on the photocatalytic activity of Nd-modified TiO₂

• Patrycja Parnicka,
• Paweł Mazierski,
• Tomasz Grzyb,
• Wojciech Lisowski,
• Ewa Kowalska,
• Bunsho Ohtani,
• Adriana Zaleska-Medynska and
• Joanna Nadolna

Beilstein J. Nanotechnol. 2018, 9, 447–459, doi:10.3762/bjnano.9.43

• heat treatment at 450 °C. The absence of peaks corresponding to Nd2O3 in the XRD patterns can be ascribed to the following phenomena: The content of Nd3+ ions was too small or highly dispersed and was below the detection limit of the diffractometer, Nd3+ was present in the form of an amorphous phase or

Engineering of oriented carbon nanotubes in composite materials

• Razieh Beigmoradi,
• Abdolreza Samimi and
• Davod Mohebbi-Kalhori

Beilstein J. Nanotechnol. 2018, 9, 415–435, doi:10.3762/bjnano.9.41

• sample can be amorphous, crystalline or a macromolecule (e.g., polymer molecule). SAXS provides information about electron density fluctuations that occur in the sample that is calculated by analyzing the intensity of scattered X-rays with a scattering angle of 0.1–5°. The local inhomogeneity in

• amorphous materials, colloidal particles, and agglomerated particles can be identified by this method. Also, long-range order and the distance between the particles in a collection of polymer molecules can be determined by using SAXS and structural models. This method is non-destructive and can be used for

Photocatalytic and adsorption properties of TiO₂-pillared montmorillonite obtained by hydrothermally activated intercalation of titanium polyhydroxo complexes

• Mikhail F. Butman,
• Nikolay L. Ovchinnikov,
• Nikita S. Karasev,
• Nataliya E. Kochkina,
• Alexander V. Agafonov and
• Alexandr V. Vinogradov

Beilstein J. Nanotechnol. 2018, 9, 364–378, doi:10.3762/bjnano.9.36

• stems from imparting higher acid resistance to the pillared MM, which is important when it is used for photocatalysis in highly acidic media. In particular, hydrothermal treatment accelerates crystallization and formation of clusters which grow and produce amorphous TiO2 nanoparticles in the interlayer