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

• modified with DSPE–PEG–COOH was determined by linear fitting of various Fe concentrations from 0.01 to 0.2 mM in water and 2% w/w agarose. Image acquisition was performed in the spin echo mode with the following parameters: repetition time 10 s, echo times 16, 24, …, 256 ms, flip angle 180°, resolution 640

Two-dimensional semiconductors pave the way towards dopant-based quantum computing

• José Carlos Abadillo-Uriel,
• Belita Koiller and
• María José Calderón

Beilstein J. Nanotechnol. 2018, 9, 2668–2673, doi:10.3762/bjnano.9.249

• may affect device performance and reproducibility [1]. Few-donor specific configurations were explored by Kane [2] in his Si quantum-computer proposal, based on an array of donors in which each of them acts as a spin qubit. This, in principle, leads to a scalable quantum computer and would be

• compatible with the existing Si-based transistor industry. For spin qubits, Si has the additional advantage of sustaining very long spin-coherence times, up to seconds for isotopically purified Si [3]. The effort to understand single-donor behavior has led to significant raise of expertise on the

• oscillations [11]. This problem can be deterrent to the implementation of quantum computing in Si due to the relative lack of control about the exact position of dopants in the bulk. Alternative proposals suggested to overcome this difficulty include hybrid dopant–quantum dot structures [12][13], a charge–spin

Silicene, germanene and other group IV 2D materials

• Patrick Vogt

Beilstein J. Nanotechnol. 2018, 9, 2665–2667, doi:10.3762/bjnano.9.248

• that the two sub-lattices in silicene, resulting from the buckling, are moved further apart by an orthogonal electric field, which leads to a band gap opening [7][8]. Another important advantage of these new materials is the significant spin–orbit interaction, which also increases with increasing

• atomic size of the involved elements. This opens the way to observe a quantum spin Hall effect, for example, in germanene or stanene in an accessible temperature range, possibly even at room temperature. The occurrence of topologically nontrivial properties will be more robust for the heavier

• constituting elements because of the related stronger spin–orbit interaction. Topological properties are expected to enable entirely new concepts in electronic devices. These characteristics make the young class of buckled 2D elemental materials a new progressing research field with anticipated outstanding

Polarization-dependent strong coupling between silver nanorods and photochromic molecules

• Gwénaëlle Lamri,
• Alessandro Veltri,
• Jean Aubard,
• Pierre-Michel Adam,
• Nordin Felidj and
• Anne-Laure Baudrion

Beilstein J. Nanotechnol. 2018, 9, 2657–2664, doi:10.3762/bjnano.9.247

• , we diluted the sample in a poly(methyl methacrylate) (PMMA) solution in toluene and spin-coated them onto the sample. The phototransition is realized by illuminating the sample with a Xe lamp filtered with a 400 nm low-pass filter. The excitation lasts two minutes and the polymer film becomes violet

Improved catalytic combustion of methane using CuO nanobelts with predominantly (001) surfaces

• Qingquan Kong,
• Yichun Yin,
• Bing Xue,
• Yonggang Jin,
• Wei Feng,
• Zhi-Gang Chen,
• Shi Su and
• Chenghua Sun

Beilstein J. Nanotechnol. 2018, 9, 2526–2532, doi:10.3762/bjnano.9.235

• forms, but spin-polarization for lowly coordinated Cu on the surface and radicals involved in CH4 oxidation deserves serious consideration. For instance, the difference in calculated adsorption energies with and without spin-polarization can be as high as 0.1–0.2 eV, with geometries showing slight

• differences too. Therefore, all energies and geometries shown below are based on spin-polarized calculations. Starting from clean (001), CH4 is firstly adsorbed with AE = −0.86 eV, followed by a spontaneous dissociation with CH3 and H adsorbed on surface oxygen, as depicted in Figure 4a–c. Similar as

• (Hiden MS HPR20) with a secondary electron multiplier detector. Methane conversion was defined as: (influent concentration of CH4 − effluent concentration of CH4)/influent concentration of CH4 × 100%. Theoretical calculations Spin-polarized DFT calculations were performed under the generalized gradient

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

• an anomalous Hall effect above room temperature, confirming the presence of spin-polarized carriers. Electron microscopy, atomic and magnetic force microscopy results suggest that the films under study have a homogenous columnar structure in the bulk while MnSb inclusions accumulate near the surface

• doped by Mn [1][2][3]. Among these systems, the most well-known and extensively studied is Ga1−xMnxAs. Here Mn atoms substitute Ga atoms and establish a ferromagnetic state realized through carrier-induced indirect exchange between Mn atoms by a Zener–RKKY mechanism accompanied by the spin polarization

• 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

Droplet-based synthesis of homogeneous magnetic iron oxide nanoparticles

• Christian D. Ahrberg,
• Ji Wook Choi and
• Bong Geun Chung

Beilstein J. Nanotechnol. 2018, 9, 2413–2420, doi:10.3762/bjnano.9.226

• by laser cutting from acrylic polymers [27]. Through these devices, it was possible to reduce reaction times significantly compared to batch reactions. Furthermore, in the case of spin-crossover particles, a 20-fold downsizing of particles compared to batch reactions could be observed [29]. Although

High-throughput micro-nanostructuring by microdroplet inkjet printing

• Hendrikje R. Neumann and
• Christine Selhuber-Unkel

Beilstein J. Nanotechnol. 2018, 9, 2372–2380, doi:10.3762/bjnano.9.222

• surfaces by a dip-coating or spin-coating process. Using this method, the spacing of the nanoparticles is controlled by the size of the micelles and by the coating conditions. Whereas block copolymer micelle nanolithography is a high-throughput method for generating well-ordered nanoparticle patterns at

• spacing between a few tens to several hundreds of nanometers is block copolymer micelle nanolithography (BCML) [8]. This technique is based on the self-assembly of metal-containing micelles on surfaces during dip-coating or spin-coating. BCML is very efficient in coating large areas with nanoparticles in

• quasi-hexagonal arrays. The spacing between the nanoparticles is controlled by the block copolymer used for forming the micelles and by the coating conditions, e.g., spin-coating and dip-coating parameters. BCML has been realized for preparing arrays of different types of nanoparticles, including gold

Magnetism and magnetoresistance of single Ni–Cu alloy nanowires

• Andreea Costas,
• Camelia Florica,
• Elena Matei,
• Maria Eugenia Toimil-Molares,
• Ionel Stavarache,
• Andrei Kuncser,
• Victor Kuncser and
• Ionut Enculescu

Beilstein J. Nanotechnol. 2018, 9, 2345–2355, doi:10.3762/bjnano.9.219

• coherent such as rotation to the more complex transversal and vortex wall modes), depending on the wire diameter [2][3][4][5]. Accordingly, the associated magnetoresistive phenomena due to scattering of conduction electrons on different field-dependent spin configurations can be also tuned. The magnetic

• the shape anisotropy). It is worth mentioning that Δρ might be positive or negative depending on whether the electron conduction is dominant by spin-up or spin-down electron scattering as well as by the ratio between the spin–orbit coupling parameter and the splitting of the uppermost bands of the

• perpendicular geometry is almost insensitive to values of the stiffness constant, but decreases strongly with the saturation magnetization. The evolution of the spin structure of the wire is similar to one of a magnetic monodomain, with gradual in-field reorientation for almost all spins (only the outermost

Block copolymers for designing nanostructured porous coatings

• Roberto Nisticò

Beilstein J. Nanotechnol. 2018, 9, 2332–2344, doi:10.3762/bjnano.9.218

• copolymers were spin-coated onto a macroporous substrate (namely, silicon microsieves with pores of 5 µm width). Since the goal was to obtain a perpendicular cylindrical morphology, a possible technical solution is the addition of small molecules (or salts) able to stabilize a preferentially interaction with

• close-packed spherical system was obtained by solvent evaporation induced self-assembly (EISA) process. Different pore sizes can be obtained by changing the block length in the soft templates. By coupling the spin-coating deposition technique with the soft-templating approach, mesoporous silica coatings

• also be produced by spin-coating deposition followed by calcination in order to obtain a nanostructured titania layer [106]. The thermal degradation of the organic polymeric template was successfully achieved without causing a collapse of the titania nanoarchitecture. The driving force behind these

Optimization of the optical coupling in nanowire-based integrated photonic platforms by FDTD simulation

• Nan Guan,
• Andrey Babichev,
• Martin Foldyna,
• Dmitry Denisov,
• François H. Julien and
• Maria Tchernycheva

Beilstein J. Nanotechnol. 2018, 9, 2248–2254, doi:10.3762/bjnano.9.209

• encapsulating spin-on-glass layer partially covering the NW is considered (used as a mechanical support for the contacts). The NW LED is buried to one half of its diameter into this spin-on-glass (SiOx) layer, and the SiNx waveguide is positioned on top of the spin-on glass. In the optimization, calculations

• without the spin-on-glass layer are also performed. The LED is connected to a straight SiNx waveguide, which has a thickness chosen to match the top surface of the guide with the top facet of the lying hexagonal NW. The end of the NW overlaps with the waveguide over a 1.5 µm long segment. On the opposite

• end of the waveguide, a horizontal NW detector is positioned, with its 1.5 µm long end overlapped with the waveguide, and it is also embedded into a spin-on-glass layer. The axes of the LED and detector NWs are aligned with the waveguide direction as shown in Figure 1a. The optical refractive indices

Lead-free hybrid perovskites for photovoltaics

• Oleksandr Stroyuk

Beilstein J. Nanotechnol. 2018, 9, 2209–2235, doi:10.3762/bjnano.9.207

• role in the efficiency of the solar cells based on this light harvester. This fact stimulated a screening of suitable solvents and deposition conditions, revealing dimethylsulfoxide (DMSO) as one of the most promising candidates for spin-coating deposition technology [113][114], which produced uniform

• for the thermodynamics-driven formation of HPs, resulting in a higher material quality and reproducibility as compared to the conventional kinetically quenched syntheses (solvent evaporation, spin or spray coating). The shape control over CsSnX3 nanoscale phases grown in the presence of tri

• oriented parallel to the substrate when the HP is spin-coated from DMSO and perpendicular – if the deposition occurs from N,N-dimethylformamide (DMF). The CB energy position was found to strongly depend on the HP composition (Figure 8b). This allows for the search of an optimum between the efficiency of

Influence of the thickness of an antiferromagnetic IrMn layer on the static and dynamic magnetization of weakly coupled CoFeB/IrMn/CoFeB trilayers

• Deepika Jhajhria,
• Dinesh K. Pandya and
• Sujeet Chaudhary

Beilstein J. Nanotechnol. 2018, 9, 2198–2208, doi:10.3762/bjnano.9.206

• that with the increase in IrMn layer thickness a nearly linear enhancement of the effective magnetic damping constant occurs, which is associated with the simultaneous influence of spin pumping and interlayer exchange coupling effects. An extrinsic contribution to the linewidth originating from the two

• . Keywords: ferromagnetic resonance; interlayer exchange coupling; magnetic damping; magnetic thin films; spin pumping; Introduction Traditionally, antiferromagnets (AF) are known to play only a static role by pinning adjacent ferromagnetic (FM) layers via exchange bias in spin-valve devices [1]. Recently

• , AF-based spintronics is gaining momentum because of the unique properties such as zero net magnetization, no stray fields, low magnetic susceptibility, large spin–orbit coupling, ultrafast dynamics and large magneto-transport effects [2][3][4][5][6]. Several of the effects such as tunnel anisotropic

Interaction-induced zero-energy pinning and quantum dot formation in Majorana nanowires

• Samuel D. Escribano,
• Alfredo Levy Yeyati and
• Elsa Prada

Beilstein J. Nanotechnol. 2018, 9, 2171–2180, doi:10.3762/bjnano.9.203

• features are observed in recent experiments on the detection of Majoranas and could thus help to properly characterize them. Keywords: hybrid superconductor–semiconductor nanowires; interactions; Majorana bound states; quantum dots; Introduction Semiconducting nanowires with strong spin–orbit interaction

• some critical Zeeman field without the expected oscillatory pattern [12][19][24][25]. Several mechanisms have been proposed to account for the reduction or lack of oscillations, such as smooth confinement [21][26][27][28], strong spin–orbit coupling [29], position-dependent pairing [30], orbital

• annihilation operators, and σ and τ are the Pauli matrices in spin and Nambu space, respectively. The model is defined by setting the parameters m*, μ, α, VZ and Δ, corresponding to the effective mass, the chemical potential, the spin–orbit coupling, the Zeeman energy caused by an external magnetic field, and

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

Spin-coated planar Sb₂S₃ hybrid solar cells approaching 5% efficiency

• Pascal Kaienburg,
• Benjamin Klingebiel and
• Thomas Kirchartz

Beilstein J. Nanotechnol. 2018, 9, 2114–2124, doi:10.3762/bjnano.9.200

• demonstrated an efficiency exceeding 7% when assembled in an extremely thin absorber configuration deposited via chemical bath deposition. More recently, less complex, planar geometries were obtained from simple spin-coating approaches, but the device efficiency still lags behind. We compare two processing

• , spin-coating of different antimony- and sulfur-containing precursors was proposed [29][36][37]. A metal-organic complex is formed in solution which is then spin-coated and afterwards thermally decomposed. Just like for CBD [2][41] or ALD [22][32] the resulting amorphous film needs to be annealed at

• ] fabricated pinhole-free layers with large grains and the so-far highest reported efficiency of 4.3% for spin-coated planar Sb2S3 solar cells as can be seen from Figure 1. However, this route includes Sb2O3 as a precursor whose detrimental impact has been discussed above. While these initial results on spin

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

• /mL and stirred for 2 days. The micelles were loaded with chlorauric acid (HAuCl4, loading parameter (L = 0.5), Sigma-Aldrich) and stirred again for 2 days. Spin-coating was applied to cover the substrate with a monolayer of the gold-loaded micelles (30 s at 2000 rpm). Electroless deposition A quartz

• duration of the process [18]. A schematic overview of the fabrication process is shown in Figure 1. In a first step a silicon substrate is coated with gold-loaded polymer micelles (Figure 1a) via spin-coating. In a second step the micelles are exposed to deep UV illumination while the substrate is covered

• silicon substrate: (a) Gold nanoparticles with block copolymer micelles after spin-coating. (b) Deep UV illumination with water and a quartz glass on top of the substrate. (c) Electroless deposition. (d) Substrate after oxygen plasma, which removes the organic components. SEM images of the gold precursor

Synthesis of a MnO₂/Fe₃O₄/diatomite nanocomposite as an efficient heterogeneous Fenton-like catalyst for methylene blue degradation

• Zishun Li,
• Xuekun Tang,
• Kun Liu,
• Jing Huang,
• Yueyang Xu,
• Qian Peng and
• Minlin Ao

Beilstein J. Nanotechnol. 2018, 9, 1940–1950, doi:10.3762/bjnano.9.185

• Mn 2p region (Figure 6c) exhibits two individual peaks at 653.9 and 642.2 eV, attributed to the Mn 2p1/2 and Mn 2p3/2 binding energies, respectively. As a result, the spin energy separation of Mn 2p peaks can be calculated as 11.7 eV, which is well in agreement with reports for MnO2 [33]. In Figure

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

• , several scenarios, such as derformation, fragmentation and implantation of the NPs, are possible [40][43]. In this study we observed partial and complete deformation of the NPs. 3D NTF patterning In order to fabricate 3D NTF patterns, a spin-coated PMMA film on a Si substrate was initially patterned via e

Improving the catalytic activity for hydrogen evolution of monolayered SnSe_2(1−x)S_2x by mechanical strain

• Sha Dong and
• Zhiguo Wang

Beilstein J. Nanotechnol. 2018, 9, 1820–1827, doi:10.3762/bjnano.9.173

• (1−x)S2x monolayer. SnSeS and SnSe0.5S1.5 monolayers show the best catalytic activity for HER at a tensile strain of 10%. This work provides a method of improvement of the catalytic activity of SnSe2(1−x)S2x monolayers. Simulation Details All calculations were performed based on spin-polarized DFT as

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

• spectrum are assigned to the 2p3/2 and 2p1/2 spin–orbit split peaks of Co (II) species, respectively (Figure 6C). Two small peaks at 786.4 eV and 803.5 eV are two satellite peaks of Co (II) species [39]. XPS is sensitive to atoms in the near-surface layer, hence only two weak peaks in Figure 6C ascribed to

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

• Abstract We have studied superconducting properties of spin-valve thin-layer heterostructures CoOx/F1/Cu/F2/Cu/Pb in which the ferromagnetic F1 layer was made of Permalloy while for the F2 layer we have taken a specially prepared film of the Heusler alloy Co2Cr1−xFexAl with a small degree of spin

• polarization of the conduction band. The heterostructures demonstrate a significant superconducting spin-valve effect, i.e., a complete switching on and off of the superconducting current flowing through the system by manipulating the mutual orientations of the magnetization of the F1 and F2 layers. The

• Heusler film as compared to Fe. This enables to approach an almost ideal theoretical magnitude of the switching in the Heusler-based multilayer with a F2 layer thickness of ca. 1 nm. Keywords: ferromagnet; proximity effect; spin valve; superconductor; Introduction Historically, the first concept to

A zero-dimensional topologically nontrivial state in a superconducting quantum dot

• Pasquale Marra,
• Alessandro Braggio and
• Roberta Citro

Beilstein J. Nanotechnol. 2018, 9, 1705–1714, doi:10.3762/bjnano.9.162

• CNR-SPIN, 84084 Fisciano (Salerno), Italy 10.3762/bjnano.9.162 Abstract The classification of topological states of matter in terms of unitary symmetries and dimensionality predicts the existence of nontrivial topological states even in zero-dimensional systems, i.e., systems with a discrete energy

• [14][15][16][17][18][19][20]. The simplest realization of a topological superconductor is the well-known Kitaev chain [3], which can be implemented in a one-dimensional system proximized by a conventional superconductor in the presence of a magnetic field and spin–orbit coupling [21][22][23][24][25

• without a finite spin–orbit coupling. The resulting topological transitions coincide with a change of the fermion parity (topological invariant) and can be identified by discontinuities in the CPR and by a measure of the critical current at low temperatures. Results and Discussion Effective model We

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

• the S 2p core-level spectrum fit presented in Figure 2c, with the S 2p3/2 and S 2p1/2 component peaks appearing at 161.8 and 163 (MoS3) eV (Table S1, Supporting Information File 1), respectively, with a spin–orbit energy separation of 1.2 eV corresponding to MoS2 (S2− oxidation state) [24]. In the O

Josephson effect in junctions of conventional and topological superconductors

• Alex Zazunov,
• Albert Iks,
• Miguel Alvarado,
• Alfredo Levy Yeyati and
• Reinhold Egger

Beilstein J. Nanotechnol. 2018, 9, 1659–1676, doi:10.3762/bjnano.9.158

• , Universidad Autónoma de Madrid, E-28049 Madrid, Spain 10.3762/bjnano.9.158 Abstract We present a theoretical analysis of the equilibrium Josephson current-phase relation in hybrid devices made of conventional s-wave spin-singlet superconductors (S) and topological superconductor (TS) wires featuring Majorana

• ] have pointed out that the physics of the Kitaev chain could be realized in spin–orbit coupled nanowires with a magnetic Zeeman field and in the proximity to a nearby s-wave superconductor. The spinful nanowire model of references [2][3] indeed features p-wave pairing correlations for appropriately

• modeled by a Kitaev chain, the supercurrent vanishes identically [31]. This supercurrent blockade can be traced back to the different (s/p-wave) pairing symmetries for the S/TS leads, together with the fact that MBSs have a definite spin polarization. For an early study of Josephson currents between