Threshold voltage decrease in a thermotropic nematic liquid crystal doped with graphene oxide flakes

• Mateusz Mrukiewicz,
• Krystian Kowiorski,
• Paweł Perkowski,
• Rafał Mazur and
• Małgorzata Djas

Beilstein J. Nanotechnol. 2019, 10, 71–78, doi:10.3762/bjnano.10.7

• nanoparticles of MgO and SiO2 [6]. Here, the effect was caused by the reduction of the order parameter S. The concentration-dependent enhancement of the electro-optic response was observed for Ti and TiO2 nanoparticles dispersed in NLC [7][8]. The significant effect of ferroelectric Sn2P2S6 on the threshold

Understanding the performance and mechanism of Mg-containing oxides as support catalysts in the thermal dry reforming of methane

• Nor Fazila Khairudin,
• Mohd Farid Fahmi Sukri,
• Mehrnoush Khavarian and
• Abdul Rahman Mohamed

Beilstein J. Nanotechnol. 2018, 9, 1162–1183, doi:10.3762/bjnano.9.108

• alkaline earth metal oxides, to the DRM catalyst to alter the catalyst acidity [39][45][46][47][48]. Numerous publications have reported on the ability of Mg-containing oxide catalysts to decrease the rate of carbon formation in a DRM reaction [18][19][49][50][51][52][53][54]. MgO exhibits superior surface

• and catalytic characteristics as a catalyst support combined with a high dispersion of small active particles for suppressing carbon formation [55]. The decreased carbon formation in DRM is due to the high basicity of MgO to capture CO2, thereby accelerating the overall reaction [34][49][51

• ]. Furthermore, its characteristics such as high thermal stability, high melting point, and low cost make MgO a promising component in endothermic reactions, especially in the DRM process [18][34][49]. Therefore, this review discusses the research regarding the DRM reaction over Mg-containing oxide catalysts as

BN/Ag hybrid nanomaterials with petal-like surfaces as catalysts and antibacterial agents

• Konstantin L. Firestein,
• Denis V. Leybo,
• Alexander E. Steinman,
• Andrey M. Kovalskii,
• Andrei T. Matveev,
• Anton M. Manakhov,
• Irina V. Sukhorukova,
• Pavel V. Slukin,
• Nadezda K. Fursova,
• Sergey G. Ignatov,
• Dmitri V. Golberg and
• Dmitry V. Shtansky

Beilstein J. Nanotechnol. 2018, 9, 250–261, doi:10.3762/bjnano.9.27

• effect against E. coli K-261. Experimental Synthesis of BN NPs and BN/Ag hybrid nanomaterials Raw BN NPs were produced using a boron oxide CVD process from a mixture of FeO, MgO, and B powders (a weight ratio 150:28:75) via a reaction of boron oxide vapour and flowing ammonia in the vertical induction

L-Lysine-grafted graphene oxide as an effective adsorbent for the removal of methylene blue and metal ions

• Yan Yan,
• Jie Li,
• Fangbei Kong,
• Kuankuan Jia,
• Shiyu He and
• Baorong Wang

Beilstein J. Nanotechnol. 2017, 8, 2680–2688, doi:10.3762/bjnano.8.268

• the Lys-GO material, the isotherm results showed that MB adsorption fitted the Langmuir isotherm model, while Cu2+ fitted the Freundlich model. The adsorption capacity of MB and Cu2+ on Lys-GO prepared from GO was much better than that of other materials, such as GO/MgO NCs or GO with different

One-step chemical vapor deposition synthesis and supercapacitor performance of nitrogen-doped porous carbon–carbon nanotube hybrids

• Egor V. Lobiak,
• Lyubov G. Bulusheva,
• Ekaterina O. Fedorovskaya,
• Yury V. Shubin,
• Pavel E. Plyusnin,
• Pierre Lonchambon,
• Boris V. Senkovskiy,
• Zinfer R. Ismagilov,
• Emmanuel Flahaut and
• Alexander V. Okotrub

Beilstein J. Nanotechnol. 2017, 8, 2669–2679, doi:10.3762/bjnano.8.267

• over magnesium-oxide-supported metal catalysts. CNx nanotubes were grown on Co/Mo, Ni/Mo, or Fe/Mo alloy nanoparticles, and MgO grains served as a template for the porous carbon. The simultaneous formation of morphologically different carbon structures was due to the slow activation of catalysts for

• carbon component. Magnesium oxide (MgO) is a suitable substrate for the synthesis of porous carbon–CNT hybrids owing its high surface area, chemical and thermal stability under growth conditions, and easy removal from carbon products using a diluted hydrochloric acid aqueous solution. Nanoporous carbon

• has been shown to form because of the carbonization of the carbon source at the surface of MgO [17]. Advantages of this method are that carbon stabilization and activation steps are not required, as well as the control of the size and the volume of the pores through the design/choice of the used MgO

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

In situ controlled rapid growth of novel high activity TiB₂/(TiB₂–TiN) hierarchical/heterostructured nanocomposites

• Jilin Wang,
• Hejie Liao,
• Yuchun Ji,
• Fei Long,
• Yunle Gu,
• Zhengguang Zou,
• Weimin Wang and
• Zhengyi Fu

Beilstein J. Nanotechnol. 2017, 8, 2116–2125, doi:10.3762/bjnano.8.211

• ) [15]. The other four peaks could be indexed to corresponding planes of TiN (JCPDF card No.65-5774) [16]. Additionally, the peaks of other byproducts, such as MgO, were not detected in this pattern. Figure 2a–c presents typical transition electron microscopy (TEM) images of the as-prepared TiB2/(TiB2

Investigation of growth dynamics of carbon nanotubes

• Marianna V. Kharlamova

Beilstein J. Nanotechnol. 2017, 8, 826–856, doi:10.3762/bjnano.8.85

• nanoparticles and MgO support in the catalyst prepared by atomic layer deposition and extremely strong metal-support interactions between epitaxial Co nanoparticles and MgO support in the catalyst prepared by impregnation. Tangential and perpendicular growth modes. In the recent years, the other two growth

• [116], CoMn [117], Ni [118], Fe [119][120], CoPt [121], CoxMg1−xO [122], CoSO4 [123], WCo alloy [124][125] and Mo2C [126]. SiO2 or MgO were used as catalyst support. The synthesis was conducted using different carbon precursors: CO [105][106][107][108][112][113][114][115][117][118][119][122][123

• in the catalyst structure, which are a result of the tuning of the catalyst composition, affected the lattice mismatch of the catalyst with certain nanotube chiralities and led to the observed changes in the chirality distribution. In [106], the effect of catalyst supports, such as SiO2 and MgO, on

Anodization-based process for the fabrication of all niobium nitride Josephson junction structures

• Massimiliano Lucci,
• Ivano Ottaviani,
• Matteo Cirillo,
• Fabio De Matteis,
• Roberto Francini,
• Vittorio Merlo and
• Ivan Davoli

Beilstein J. Nanotechnol. 2017, 8, 539–546, doi:10.3762/bjnano.8.58

• growth of NbN/AlN/NbN tunnel junctions on oxidized silicon substrates can give rise to a non-optimal barrier formation. In order to check the influence of the substrate on trilayers we plan to test our trilayer process on MgO substrates, which are known, for providing the highest quality of the tunneling

Fabrication of black-gold coatings by glancing angle deposition with sputtering

• Alan Vitrey,
• Rafael Alvarez,
• Alberto Palmero,
• María Ujué González and
• José Miguel García-Martín

Beilstein J. Nanotechnol. 2017, 8, 434–439, doi:10.3762/bjnano.8.46

• , respectively. Two different monocrystalline substrates have been used: opaque Si(001) and transparent MgO(001). The tilt angle, σ, was varied from 75 to 87°. A scheme of the set-up is depicted in Figure 1. For the sake of comparison, continuous thin films were also fabricated using the standard configuration

• . Having in mind a future scalability of the process, from an industrial point of view it is better to use the smaller tilt angle that is able to give rise to black-metal samples. Hence, 85° has been our choice for this proof of concept. Figure 5a shows a photograph of two gold samples prepared onto MgO

• black color (a) and golden color (b). For the sake of comparison, the calculated spectra of a bare Si substrate (cyan) and a continuous Au thin film (red) have been also included. (a) Photograph of two samples prepared onto MgO substrates: a continuous Au thin film prepared with σ = 0° (left) and a

Tailoring bifunctional hybrid organic–inorganic nanoadsorbents by the choice of functional layer composition probed by adsorption of Cu²⁺ ions

• Veronika V. Tomina,
• Inna V. Melnyk,
• Yuriy L. Zub,
• Aivaras Kareiva,
• Miroslava Vaclavikova,
• Gulaim A. Seisenbaeva and
• Vadim G. Kessler

Beilstein J. Nanotechnol. 2017, 8, 334–347, doi:10.3762/bjnano.8.36

• -picrylhydrazyl (DPPH) (g = 2.0036) and ions of Mn2+ in MgO matrix (g = 2.0015). The sorption of copper(II) ions on the samples analyzed with EPR was conducted from acetonitrile solutions. Electron spectra of diffuse reflectance (ESDR) of the amino-functionalized particles containing copper(II) ions were recorded

Analysis of self-heating of thermally assisted spin-transfer torque magnetic random access memory

• Austin Deschenes,
• Sadid Muneer,
• Mustafa Akbulut,
• Ali Gokirmak and
• Helena Silva

Beilstein J. Nanotechnol. 2016, 7, 1676–1683, doi:10.3762/bjnano.7.160

• contributions from Equation 3 and Equation 4 are released or absorbed on the appropriate side of the tunneling barrier depending on the current polarity. The MRAM device modeled (Figure 1) is composed of the following layers: contact | 0.5 Ta | 0.9 CoFeB (free) | 1 MgO | 0.5 Fe | 0.5 CoFeB (fixed) | 0.6 Ta

• material stack the CoFeB layers are the ferromagnetic domains of the MTJ, MgO is the thin insulating layer, and Ta/CoPd/Ru is the synthetic antiferromagnetic layer. The material stack modeled is from a device reported by Worledge et al. [8]. The thermal stability factor of the free ferromagnetic layer of

• T is the local temperature. Temperature-dependent materials properties [7][10][11][12][13][14] (Figure 3) are used for CoFeB, MgO, and Fe. The temperature-dependent thermal conductivity of CoFeB is calculated using the Wiedemann–Franz law: where L is the Lorenz number. It is assumed the annealing

Orientation of FePt nanoparticles on top of a-SiO₂/Si(001), MgO(001) and sapphire(0001): effect of thermal treatments and influence of substrate and particle size

• Martin Schilling,
• Paul Ziemann,
• Zaoli Zhang,
• Johannes Biskupek,
• Ute Kaiser and
• Ulf Wiedwald

Beilstein J. Nanotechnol. 2016, 7, 591–604, doi:10.3762/bjnano.7.52

• amorphous (a-) native oxide layer on top, on MgO(001), and on sapphire(0001) substrates. For the NPs of an approximately equiatomic composition, two different sizes were chosen: “small” NPs with diameters in the range of 2–3 nm and “large” ones in the range of 5–8 nm. The 3 nm thick FePt films, deposited by

• size of NPs: Only the smaller NPs approach a fully developed (111) orientation. On top of MgO(001) the effect of annealing on particle orientation was found to be strongest. From a random orientation in the as-prepared state observed for both, small and large FePt NPs, annealing at 650 °C for 30 min

• fabricated on MgO buffer layers for heat-assisted magnetic recording. In this experiment, 3–9 nm FePt NPs formed, while C acted as an exchange-decoupling spacer and the NPs reach an imposing MAE of 5.2 MJ·m−3, i.e., about 80% of the L10 FePt bulk value [14]. As just mentioned, if FePt films or NPs are

Hydration of magnesia cubes: a helium ion microscopy study

• Ruth Schwaiger,
• Johannes Schneider,
• Gilles R. Bourret and
• Oliver Diwald

Beilstein J. Nanotechnol. 2016, 7, 302–309, doi:10.3762/bjnano.7.28

• these oxides are in physical contact with a solid substrate such as the ones used for immobilization to perform electron or ion microscopy imaging. We used helium ion microscopy (HIM) and investigated morphological changes of vapor-phase-grown MgO cubes after vacuum annealing and pressing into foils of

• definition specific to the MgO cubes. Comparison of different regions within one sample before and after exposure to liquid water reveals different transformation processes, such as the formation of Mg(OH)2 shells that act as diffusion barriers for MgO dissolution or the evolution of brucite nanosheets

• , most importantly, without coating the samples for charge compensation. Sample charging effects that typically occur during imaging of insulating samples can be counteracted in the HIM by using a low-energy electron flood gun for charge compensation [7]. Although charging is a problem for MgO, in this

A scanning probe microscope for magnetoresistive cantilevers utilizing a nested scanner design for large-area scans

• Tobias Meier,
• Alexander Förste,
• Ali Tavassolizadeh,
• Karsten Rott,
• Dirk Meyners,
• Roland Gröger,
• Günter Reiss,
• Eckhard Quandt,
• Thomas Schimmel and
• Hendrik Hölscher

Beilstein J. Nanotechnol. 2015, 6, 451–461, doi:10.3762/bjnano.6.46

• junction consists of two ferromagnetic CoFeB-electrodes separated by a thin dielectric MgO layer, which acts like a spin-valve. The electrical conductance of the magnetic tunnel junction, therefore, strongly depends on the orientation of the magnetization of the electrodes towards each other. When

• tunneling junction varies by rotating the magnetization of the free sensing layer. Using the inverse magnetostrictive effect in the sensing layer makes the TMR stack sensitive to applied strain. We used a CoFeB (3 nm)/MgO (1.8 nm)/CoFeB (3 nm) TMR junction with an MnIr (12 nm)/CoFe (3 nm) exchange bias

• system that was annealed at about 360 °C for 1 h at a pressure of 10−6 mbar under a magnetic field of 2 kOe for a crystallization of the CoFeB electrodes and improvement of CoFeB/MgO interfaces. It also aligns the easy axis of the sensing layer and pins the reference layer due to the imposed magnetic

Influence of size, shape and core–shell interface on surface plasmon resonance in Ag and Ag@MgO nanoparticle films deposited on Si/SiO_x

• Sergio D’Addato,
• Daniele Pinotti,
• Maria Chiara Spadaro,
• Guido Paolicelli,
• Vincenzo Grillo,
• Sergio Valeri,
• Luca Pasquali,
• Luca Bergamini and
• Stefano Corni

Beilstein J. Nanotechnol. 2015, 6, 404–413, doi:10.3762/bjnano.6.40

• of Electricity and Electronics, Faculty of Science and Technology, UPV/EHU, 48080 Bilbao, Spain Materials Physics Center CSIC-UPV/EHU and Donostia International Physics Center DIPC, Paseo Manuel Lardizabal 4, 20018 Donostia-San Sebastian, Spain 10.3762/bjnano.6.40 Abstract Ag and Ag@MgO core–shell

• atmosphere gave rise to formation of a MgO shell matrix surrounding the Ag NPs. The behaviour of the surface plasmon resonance (SPR) excitation in surface differential reflectivity (SDR) spectra with p-polarised light was investigated for bare Ag and Ag@MgO NPs. It was shown that the presence of MgO around

• the Ag NPs caused a red shift of the plasmon excitation, and served to preserve its existence after prolonged (five months) exposure to air, realizing the possibility of technological applications in plasmonic devices. The Ag NP and Ag@MgO NP film features in the SDR spectra could be reproduced by

Synthesis of boron nitride nanotubes and their applications

• Saban Kalay,
• Zehra Yilmaz,
• Ozlem Sen,
• Melis Emanet,
• Emine Kazanc and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2015, 6, 84–102, doi:10.3762/bjnano.6.9

• first successful synthesis of patterned BNNTs was performed by catalytic CVD [56]. To produce pure and vertically aligned BNNTs, a Si substrate was coated with Al2O3 of 30 nm thickness, then MgO, Ni, or Fe catalysts was deposited on the surface of the Al2O3 by pulsed laser deposition. This substrate was

Nanoporous composites prepared by a combination of SBA-15 with Mg–Al mixed oxides. Water vapor sorption properties

• Amaury Pérez-Verdejo,
• Alvaro Sampieri,
• Heriberto Pfeiffer,
• Mayra Ruiz-Reyes,
• Juana-Deisy Santamaría and
• Geolar Fetter

Beilstein J. Nanotechnol. 2014, 5, 1226–1234, doi:10.3762/bjnano.5.136

• SBA-15 with MgO and tested as a drug delivery controller material or as a basic catalyst [10]. Recently, Habib et al. [11] synthesized ZSM-5/SBA-15 composites by a microwave-assisted zeolitisation. These composites presented highly specific surface areas and a pore volume with narrow porous size

• calcined hydrotalcie are observed by XRD, as the MgO periclase phase is only present in the calcined hydrotalcite [12], peak diffraction at 37°, 46° and 66° 2θ. Although no Mg–Al–O diffraction peaks are observed by XRD, such mixed oxides my contain particles so small that they are undetected by XRD. Indeed

Designing magnetic superlattices that are composed of single domain nanomagnets

• Derek M. Forrester,
• Feodor V. Kusmartsev and
• Endre Kovács

Beilstein J. Nanotechnol. 2014, 5, 956–963, doi:10.3762/bjnano.5.109

• to enforce an antiferromagnetic coupling. In all superlattices the lattice period of the layers is of crucial importance to defining its purpose and physical properties [6][7]. The properties of the spacer layers (composed of MgO or Ru, for example) between the nanomagnets, and the resulting

Quantum size effects in TiO₂ thin films grown by atomic layer deposition

• Massimo Tallarida,
• Chittaranjan Das and
• Dieter Schmeisser

Beilstein J. Nanotechnol. 2014, 5, 77–82, doi:10.3762/bjnano.5.7

• spectra were also observed in very thin TiO2 films that were grown by reactive evaporation in oxygen atmosphere at room temperature on SiO2 [18], Al2O3 [19] and MgO [20]. There, XAS spectra at the Ti-L2,3 absorption edge were analyzed within the charge-transfer multiplet (CTM) model. Within the CTM theory

• , the spectral features observed for very thin TiO2 films were addressed to a decreased ligand-field at TiO2/substrate interfaces, which was found to be increasingly important when moving from the MgO substrate to SiO2 [21]. Instead, Krüger used a first-principles multichannel multiple-scattering

• -field and pdσ at the TiO2 interface with either MgO, Al2O3 or SiO2, attributing the line shape of the Ti-L2,3 spectra to structural modifications of TiO2, changing the Slater integrals would have induced to attribute the line-shape variations to a changed Ti 3d/O 2p hybridization (and covalency) in very

Synthesis of boron nitride nanotubes from unprocessed colemanite

• Saban Kalay,
• Zehra Yilmaz and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2013, 4, 843–851, doi:10.3762/bjnano.4.95

• (Figure 4d). Peaks were observed at 2θ angles of 26.8° and 41.8° belonging to hexagonal BN. There are not any crystalline phase peaks originating from CaO, SiO2, Al2O3, MgO, SrO or Na2O in colemanite and the Fe2O3 catalyst. UV–vis, FTIR and Raman analysis of BNNTs The BNNTs were analyzed with UV–vis

Preparation of electrochemically active silicon nanotubes in highly ordered arrays

• Tobias Grünzel,
• Young Joo Lee,
• Karsten Kuepper and
• Julien Bachmann

Beilstein J. Nanotechnol. 2013, 4, 655–664, doi:10.3762/bjnano.4.73

• curves) to its opposite end (green to pink). This variation can be interpreted based on a model in which an unreacted SiO2 film is situated underneath a mixed Si/MgO layer (Figure 3c). If the spectra are fitted to deliver the thicknesses of these two layers (without any constraint on their sum), a clear

• ) layer stack used to model the ellipsometry data: the mixed layer is treated as a 1:1 mixture with the Lorentz–Lorentz model; (d) results of the fit: thicknesses of the unreacted SiO2 and converted Si + MgO depending on the distance from the sample edge. The experimental data are presented together with

Near-field effects and energy transfer in hybrid metal-oxide nanostructures

• Ulrich Herr,
• Balati Kuerbanjiang,
• Cahit Benel,
• Giorgos Papageorgiou,
• Manuel Goncalves,
• Johannes Boneberg,
• Paul Leiderer,
• Paul Ziemann,
• Peter Marek and
• Horst Hahn

Beilstein J. Nanotechnol. 2013, 4, 306–317, doi:10.3762/bjnano.4.34

• nanostructures deposited on substrates such as glass, Si wafers or MgO can be coated by introducing them into the powder-collection system. For the production of TiO2:Eu nanoparticles (NPs), we used titanium(IV) iso-propoxide (TTIP) and tris(2,2,6,6-tetramethyl-3,5-heptanedionato)europiate(III) [Eu(THMD)3] (both

Probing three-dimensional surface force fields with atomic resolution: Measurement strategies, limitations, and artifact reduction

• Mehmet Z. Baykara,
• Omur E. Dagdeviren,
• Todd C. Schwendemann,
• Harry Mönig,
• Eric I. Altman and
• Udo D. Schwarz

Beilstein J. Nanotechnol. 2012, 3, 637–650, doi:10.3762/bjnano.3.73

• sample surface. Force fields have now been recorded on NiO(001) [10][12][13], MgO/Ag(001) [14], NaCl(001) [15][16], Si(111)-(7×7) [17][18][19], HOPG [20][21], KBr(001) [9][22][23], Cu(111) [24], and CaCO3() [25] surfaces, as well as single molecules of PTCDA [26][27], pentacene [28], CO [29], C60 [30

Models of the interaction of metal tips with insulating surfaces

• Thomas Trevethan,
• Matthew Watkins and
• Alexander L. Shluger

Beilstein J. Nanotechnol. 2012, 3, 329–335, doi:10.3762/bjnano.3.37

• atomic resolution. Chromium and tungsten tips are used to image the NaCl(001) and MgO(001) surfaces. The interaction of the tips with the surface is simulated by using density-functional-theory calculations employing a mixed Gaussian and plane-wave basis and cluster-tip models. In each case, the apex of

• , NaCl(001) and MgO(001). The high symmetry of these surfaces makes their AFM images particularly difficult to interpret [3], although in the case of NaCl(001), there have been several approaches to successfully interpret atomic-resolution images [8][9][10][11]. We consider two types of metal tip, namely

• nature of the tip (i.e., a very small band gap) in the simulation, we also employ Fermi–Dirac smearing of the molecular-orbital occupation numbers, with an electronic temperature of 2500 K. Both the NaCl(001) and MgO(001) surfaces were modeled using a periodic slab, 6 × 6 atoms in area and three atomic