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

• diameter from 6 to 25 nm. The 25 nm and 44 nm diameter NPs show similar theranostic performance. In in vitro experiments we detected the death of 4T1 mouse breast cancer cells at a rate of 79 ± 8% after exposure to 25 nm Fe3O4–Au hybrids for 30 min in an ac magnetic field (AMF) with 261–393 kHz and 25 mT

• light scattering data (Table S1, Supporting Information File 1). The ability of magnetite NPs to increase the T2-contrast in MRI arises from the creation of huge magnetic field gradients, accelerating the relaxation rate of water protons in the vicinity of the NPs [56]. The correlation of r2-relaxivity

• 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

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

• components parallel to the surface are much stronger than those of the perpendicular y-components. This effect is particularly clearly visible for the magnetic field. The calculated absorbance as a result of the FDTD/DFT simulation is shown in Figure 15. We can observe a quite good agreement with the

Cytotoxicity of doxorubicin-conjugated poly[N-(2-hydroxypropyl)methacrylamide]-modified γ-Fe₂O₃ nanoparticles towards human tumor cells

• Zdeněk Plichta,
• Yulia Kozak,
• Rostyslav Panchuk,
• Viktoria Sokolova,
• Matthias Epple,
• Lesya Kobylinska,
• Pavla Jendelová and
• Daniel Horák

Beilstein J. Nanotechnol. 2018, 9, 2533–2545, doi:10.3762/bjnano.9.236

• from MRI contrast agents to drug-delivery systems, local heat sources in magnetic hyperthermia therapy of tumors, magnetically assisted transfection of cells, and magnetic field-assisted separation techniques. Let us to note that MRI is already widely used in human medicine and several iron-oxide-based

• using a magnetic field allowing for easy separation and/or targeted delivery in the organism [26]. In this report, citrate-treated maghemite nanoparticles and a novel PHPMA-based surface coating were used to ensure biocompatibility, minimal immunogenicity and to provide reactive functional groups for

Nanocellulose: Recent advances and its prospects in environmental remediation

• Katrina Pui Yee Shak,
• Yean Ling Pang and
• Shee Keat Mah

Beilstein J. Nanotechnol. 2018, 9, 2479–2498, doi:10.3762/bjnano.9.232

• magnetic field. As a result, magnetic nanomaterials have drawn increasing attention. Nanocellulose incorporated with other magnetic nanomaterials is presented as an excellent composite adsorbent with magnetic properties. For example, a core–shell cellulose magnetite (Fe3O4) polymeric ionic liquid magnetic

• dioxide sample. The incorporation of magnetite was able to inhibit the photodegradation of the cellulose structure during UV irradiation and this hybrid structure demonstrated high catalyst recyclability using an external magnetic field. Nanoparticles generally tend to aggregate, leading to difficulties

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

• magnetization as function of the magnetic field for the sample GM3 (see Table 1) for magnetic field orientations parallel to the sample plane and perpendicularly to it. The presence of a well-pronounced hysteresis suggests that ferromagnetic ordering in these materials appears at T > 300 K. This is more evident

• agreement with values of Hc ≈ 130 Oe and Hsat ≈ 4 kOe obtained from SQUID data with the magnetic field oriented perpendicularly to the sample plane. Note, that the values of Hc and Hsat in Table 1 were obtained with the magnetic field oriented parallel to the sample plane. The difference between the values

• This work was partially supported by Russian Foundation for Basic Research (grants #17-02-00262 and #16-03-00150) and by Ministry of Education and Science of Russian Federation (grant #16.2814.2017/PCh). (a) Magnetization as a function of the magnetic field for sample GM3 at T = 300 K. Measurements

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

• implication in the magnetoresistance behavior, which has to remain constant when passing the applied magnetic field through any vicinity of the switching field (Figure 2). In order to support theoretically the mechanism of a S–W-like coherent rotation in transversal geometry also for nanowires with diameters

• no field applied, the magnetization lies along the wire due to the strong shape anisotropy. The perpendicular magnetoresistance as a function of the induction of the magnetic field (left column) and the corresponding magnetization reversal in perpendicular geometry (right column) as calculated via

• Equation 5, for single Ni–Cu alloy nanowires of different Ni concentrations. Hysteresis loops showing the average magnetic moment of Ni atoms as a function of the applied magnetic field, obtained from SQUID magnetometry measurements at 300 K on arrays of Ni–Cu nanowires of different compositions (54 and 92

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

• the propagation of light inside each sublayer separately. The matrix size depends on the number of modes considered. Based on this matrix, complex vectors of the electric and magnetic field, E and H, inside each sublayer can be defined at the end of the calculation. Eigenvectors of the matrix define

Metal–dielectric hybrid nanoantennas for efficient frequency conversion at the anapole mode

• Valerio F. Gili,
• Lavinia Ghirardini,
• Davide Rocco,
• Giuseppe Marino,
• Ivan Favero,
• Iännis Roland,
• Giovanni Pellegrini,
• Lamberto Duò,
• Marco Finazzi,
• Luca Carletti,
• Andrea Locatelli,
• Aristide Lemaître,
• Dragomir Neshev,
• Costantino De Angelis,
• Giuseppe Leo and
• Michele Celebrano

Beilstein J. Nanotechnol. 2018, 9, 2306–2314, doi:10.3762/bjnano.9.215

• the electric field, E0, polarized along the y-axis with respect to the reference system of Figure 2a. For the dispersion of the refractive index of Al0.18Ga0.82As we used the analytical model proposed in [39]. In Figure 2b,c both the electric and magnetic field enhancements are depicted, respectively

• ) Electric field vector map at 1550 nm for the proposed structure. b) Electric and c) magnetic field distribution in the hybrid nanoantenna at 1550 nm. d) The full multipolar decomposition of the first five contributing multipole moments: electric dipole (Pe), magnetic dipole (Md), toroidal dipole (Td

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

• was varied (5, 10, 15, 20 and 25 nm). No cooling of the samples in an external magnetic field through the Néel temperature (TN) was performed. For accurately estimating the thicknesses of individual layers and interfacial roughness, X-ray reflectivity (XRR) measurements were performed using a

• sweeping the in-plane external dc magnetic field through resonance at a constant microwave frequency (f). Here, the external field was modulated using a pair of Helmholtz coils, which provide a small ac field (211.5 Hz) of 1.3 Oe, and in combination with lock-in detection, the field derivative of FMR

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

• , Universidad Autónoma de Madrid, E-28049 Madrid, Spain 10.3762/bjnano.9.203 Abstract Majorana modes emerge in non-trivial topological phases at the edges of specific materials such as proximitized semiconducting nanowires under an external magnetic field. Ideally, they are non-local states that are charge

• in these regions disperse with magnetic field (or chemical potential) and appear below the induced gap in the wire spectrum (in blue in Figure 1b). In the topological regime, dot-like levels interact with Majorana states, anticrossing them when they approach zero energy. Similar phenomena were

• 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

Phosphorus monolayer doping (MLD) of silicon on insulator (SOI) substrates

• Noel Kennedy,
• Ray Duffy,
• Luke Eaton,
• Dan O’Connell,
• Scott Monaghan,
• Shane Garvey,
• James Connolly,
• Chris Hatem,
• Justin D. Holmes and
• Brenda Long

Beilstein J. Nanotechnol. 2018, 9, 2106–2113, doi:10.3762/bjnano.9.199

• wet-chemistry functionalization due to the precise dimensions needed for analysis. The Hall measurement system applies current and magnetic field and measures voltages and resistances. It then infers mobility and carrier properties from these measurements. The sheet resistivity (ρs) is directly

• measured first by the four-point method, followed by the sheet Hall coefficient (sheet Hall resistance divided by magnetic field) as measured by Hall effect, RHS = VH/(I·B), where VH is the measured Hall voltage, I is the applied current and B is the applied magnetic field. Since ρs and RHS are now

• effect measurements Room temperature Hall effect measurements are performed using a controllable electromagnet in a LakeShore Model 8404 Hall effect measurement system (HMS) with dc and ac magnetic field capability in the range of ±1.7 T for dc, and of 1.2 T RMS (ac, 50/100 mHz), respectively. The ac

A variable probe pitch micro-Hall effect method

• Maria-Louise Witthøft,
• Frederik W. Østerberg,
• Janusz Bogdanowicz,
• Rong Lin,
• Henrik H. Henrichsen,
• Ole Hansen and
• Dirch H. Petersen

Beilstein J. Nanotechnol. 2018, 9, 2032–2039, doi:10.3762/bjnano.9.192

• MHE measurement itself is performed simply by placing a micro four-point probe (M4PP) in parallel and close proximity to an insulating boundary, with an orthogonal magnetic field applied. Then the measured resistance will have three contributions: a drift term, a Hall effect term and a magnetoresitive

•  7 generalizes the results from Figure 6 in the sense that the sensitivity of each parameter to electrical noise is investigated for varying RH/R0 ratios. A small RH/R0 ratio corresponds to a low mobility sample or a setup using a small magnetic field, whereas a higher ratio indicates the opposite

• microHall-A300 tool from CAPRES A/S and an M7PP with an electrode pitch of 10 μm. The M7PP used consisted of nickel-coated poly-silicon cantilever electrodes extending from the edge of a silicon die. A magnetic field with the flux density Bz = 600 mT was applied perpendicular to a boron-doped (1015 cm−2

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

• indicates that both of the samples show superparamagnetic behavior at room temperature [31]. The maximum saturation magnetizations of Fe3O4/diatomite and MnO2/Fe3O4/diatomite were measured to be 16.57 and 10.61 emu/g, respectively, which make the composites very easy to be separated by an external magnetic

• field (inset). The decrease of the maximum saturation magnetizations after the treatment with KMnO4 is largely ascribed to the outer MnO2 shell, the saturation magnetization of which is much lower than the Fe3O4 nanoparticles. XPS measurements were carried out to determine the surface chemical

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

• resistance, then a magnetic field is applied orthogonally to the sample surface to measure the sheet Hall coefficient RSH, which is finally used to deduce NH and µH. Several classical Van der Pauw shapes were tested to perform electrical measurements (square, Greek cross and bridge “bar-shaped” structures

Tunable fractional Fourier transform implementation of electronic wave functions in atomically thin materials

• Daniela Dragoman

Beilstein J. Nanotechnol. 2018, 9, 1828–1833, doi:10.3762/bjnano.9.174

• proposed already. For instance, it was shown that a tunable continuous FrFT of the wave function of a 2DEG can be obtained by applying an in-plane magnetic field [14], while a discrete Fourier transform based on an array of four quantum waveguides was demonstrated in [19]. The advantage of the proposal put

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

• and NPLs-2.5-800 in Figure 5A indicate their strong magnetic response to the varying magnetic field, which is highly favorable for fast separation after the adsorption process. Figure 5B shows that the black adsorbent material (NPLs-2.5-800) can be attracted by a magnet within 20 s, indicating the

• dopamine hydrochloride concentrations of: (a) 2.0, (b) 2.5, (c) 1.0 and (d) 2.5 g/L. (B) A photograph illustrating the physical separation of the adsorbent material (NPLs-2.5-800) from water in the presence of an external magnetic field (permanent magnet). (A) Raman spectrum and (B–D) XPS spectra of the

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

• magnetic field, should yield a complete switching on and off of the superconducting current in such a construction. A number of experimental studies have confirmed the predicted effect of the mutual orientation of magnetizations in the F1/S/F2 structure on Tc [5][6][7][8][9]. However, the major difficulty

Magnetic properties of Fe₃O₄ antidot arrays synthesized by AFIR: atomic layer deposition, focused ion beam and thermal reduction

• Juan L. Palma,
• Alejandro Pereira,
• Raquel Álvaro,
• José Miguel García-Martín and
• Juan Escrig

Beilstein J. Nanotechnol. 2018, 9, 1728–1734, doi:10.3762/bjnano.9.164

• NanoMOKE3 from Quantum Design with the applied magnetic field applied parallel to the substrate plane and reaching a maximum value of 1.5 kOe. The laser spot was placed into each antidot array and, in order to check that the spot was located in the right position, the longitudinal reflectivity was measured

• . Magnetic field was applied along the 0° and 45° directions when measuring the square arrays (i.e., the first and second neighbors directions, respectively) and along 0° and 30° direction when measuring the hexagonal arrays (first and second neighbors directions in this case, respectively). Additionally

• lattice parameters are slightly larger than those of the arrays with smaller lattice parameters (i.e., the curves exhibit a wider and more vertical shape), regardless of whether we treat square or hexagonal arrays. Small differences exist between the loops obtained with the external magnetic field applied

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

• [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

• consider a semiconducting quantum dot in a magnetic field B and coupled with two superconducting leads, as shown in Figure 1. We assume that the only effect of the magnetic field is the lifting of the spin degeneracy via the Zeeman effect, and we neglect orbital effects of the field. Moreover, we assume

• the critical current by varying the magnetic field, or by varying, e.g., the energy level ε in a constant field B. Figure 4b shows the critical current of the junction as a function of the Zeeman field. As one can see, the critical current is finite in the trivial P = 1 state when |B| < Bmin (i.e., λ

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

• magnetic impurity in a local magnetic field. We here analyze the S–QD–TS setup in Figure 1a in some detail, where a quantum dot (QD) is present within the S–TS junction region. The QD is modeled as an Anderson impurity [36], which is equivalent to a spin-1/2 quantum impurity over a wide parameter regime

• . Once spin mixing is induced by the magnetic impurity and the local magnetic field, we predict that a finite Josephson current flows even in the deep topological limit. In particular, in the cotunneling regime, we find an anomalous Josephson effect with finite supercurrent at vanishing phase difference

• vanishing phase difference ( = 0) [45][46][72]. One can equivalently view this effect as a φ0-shift in the CPR, I() = Ic sin( + φ0). An observation of this φ0-junction behavior could then provide additional evidence for MBSs (see also [47]), where Equation 23 shows that the local magnetic field is required

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

• with the methyl methacrylate (MMA) monomer. The resulting suspension of magnetic nanoparticles decorated with poly(methyl methacrylate) (PMMA) chains in toluene were colloidal, even in the presence of a magnetic field gradient. Nanocomposites were precipitated from these suspensions. The transmission

• coercivity in the absence of an external magnetic field [1][2]. Their colloidal suspensions are vital in a variety of technological [3] and biomedical applications [4], such as contrast agents in magnetic resonance imaging (MRI) [5][6], targeted drug delivery [6] and magnetic hyperthermia based on the

• selective heating of magnetic nanoparticles using an external AC magnetic field [7][8]. While magnetic nanoparticles exhibit unique physico-chemical properties, they also tend to agglomerate, leading to the loss of their interesting properties and their potential for applications. Organic/inorganic

Closed polymer containers based on phenylboronic esters of resorcinarenes

• Tatiana Yu. Sergeeva,
• Rezeda K. Mukhitova,
• Irek R. Nizameev,
• Marsil K. Kadirov,
• Polina D. Klypina,
• Albina Y. Ziganshina and
• Alexander I. Konovalov

Beilstein J. Nanotechnol. 2018, 9, 1594–1601, doi:10.3762/bjnano.9.151

• pulsed gradient unit capable of producing magnetic-field pulse gradients in the z-direction of about 56 G/cm. D2O was used as solvent in all experiments. Chemical shifts were reported relative to H2O (δ = 4.7 ppm) as an internal standard. Measurements by the DSC and TGA methods were carried out with a

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

• properties of cobalt nanoholes were investigated by the magneto-optical Kerr effect technique in longitudinal configuration. The samples were placed between the poles of a GMW 3470 electromagnet, where the magnetic field intensity was measured by a Group3 Teslameter probe. A He–Ne laser beam (wavelength 633

• their possible applications in plasmonic and magnonic fields. In both cases, nanoparticle size, distribution and nanostructure mesospacing are key parameters for the control of the electric or magnetic field distribution and intensity on the investigated area. Concerning plasmonic applications, the

Solid-state Stern–Gerlach spin splitter for magnetic field sensing, spintronics, and quantum computing

• Kristofer Björnson and
• Annica M. Black-Schaffer

Beilstein J. Nanotechnol. 2018, 9, 1558–1563, doi:10.3762/bjnano.9.147

• ferromagnetic leads, the device can be used for sensitive measurements of magnetic field strengths. The same setup can also be used to implement a spintronic switch. Instead using normal metallic leads, we show that a switchable spintronics NOT-gate can be constructed. Finally, we also demonstrate how a

• coordinate x1 = r(2π − θ) and x2 = rθ along the upper and lower edges, respectively. The eigenvalue equations along the two edges are then and the corresponding eigenstates can be written as We now thread a magnetic flux of magnetic field strength B through the hole. To describe this we choose the vector

• spin-up electrons, the only relevant matrix element for the scattering matrix is The conductance is therefore given by It is clear that the very strong dependence of the current on the magnetic flux Br2π makes this setup ideal for measuring magnetic field strength, as a potential alternative to

Robust topological phase in proximitized core–shell nanowires coupled to multiple superconductors

• Tudor D. Stanescu,
• Anna Sitek and
• Andrei Manolescu

Beilstein J. Nanotechnol. 2018, 9, 1512–1526, doi:10.3762/bjnano.9.142

• Science and Engineering, Reykjavik University, Menntavegur 1, IS-101 Reykjavik, Iceland 10.3762/bjnano.9.142 Abstract We consider core–shell nanowires with prismatic geometry contacted with two or more superconductors in the presence of a magnetic field applied parallel to the wire. In this geometry, the

• lowest energy states are localized on the outer edges of the shell, which strongly inhibits the orbital effects of the longitudinal magnetic field that are detrimental to Majorana physics. Using a tight-binding model of coupled parallel chains, we calculate the topological phase diagram of the hybrid

• longitudinal magnetic field. The system is predicted to host zero-energy Majorana modes localized at the two ends of the nanowire [5][7][8]. These zero-energy states combine equal proportions of electrons and holes and are created by second quantized operators satisfying the “Majorana condition” γ† = γ. The