Formation and shape-control of hierarchical cobalt nanostructures using quaternary ammonium salts in aqueous media

• Ruchi Deshmukh,
• Anurag Mehra and
• Rochish Thaokar

Beilstein J. Nanotechnol. 2017, 8, 494–505, doi:10.3762/bjnano.8.53

• diffractometer using Cu Kα1 radiation. The magnetic properties of the samples dried in a vacuum desiccator were determined by vibrating sample magnetometry (Quantum Design, USA). The samples were also analyzed using X-ray photoelectron spectroscopy (XPS, VG Micro Tech ESCA-3000) using non-monochromatic, Al Kα

Grazing-incidence optical magnetic recording with super-resolution

• Gunther Scheunert,
• Sidney. R. Cohen,
• René Kullock,
• Ryan McCarron,
• Katya Rechev,
• Ifat Kaplan-Ashiri,
• Ora Bitton,
• Paul Dawson,
• Bert Hecht and
• Dan Oron

Beilstein J. Nanotechnol. 2017, 8, 28–37, doi:10.3762/bjnano.8.4

• Figure 2a, although the actual layer structure is much more complex, e.g., the recording layer consists of SiO2-embedded CoCrPt grains, the seed layer stack contains multiple layers, and the soft underlayer consists of a Fe-rich alloy. Superconducting quantum interference device (SQUID) magnetometry was

• (University of Würzburg). Further, we would like to thank T. Adler and his colleagues at LOT Germany for magnetic characterization of the samples by SQUID magnetometry. PD and RMcC acknowledge support from US-Ireland Partnership R&D Project USI 043 and EPSRC grant EP/1038411/1. GS and DO acknowledge support

A novel electrochemical nanobiosensor for the ultrasensitive and specific detection of femtomolar-level gastric cancer biomarker miRNA-106a

• Maryam Daneshpour,
• Kobra Omidfar and
• Hossein Ghanbarian

Beilstein J. Nanotechnol. 2016, 7, 2023–2036, doi:10.3762/bjnano.7.193

• the assay. Hence, the magnetization curve of prepared NPs was studied by Vibrating sample magnetometry (VSM) at room temperature. The hysteresis curves in Figure S2B (Supporting Information File 1) show that the saturation magnetization of naked magnetic NPs (70.62 emu/g) has decreased after coating

Cubic chemically ordered FeRh and FeCo nanomagnets prepared by mass-selected low-energy cluster-beam deposition: a comparative study

• Veronique Dupuis,
• Anthony Robert,
• Arnaud Hillion,
• Ghassan Khadra,
• Nils Blanc,
• Damien Le Roy,
• Florent Tournus,
• Clement Albin,
• Olivier Boisron and
• Alexandre Tamion

Beilstein J. Nanotechnol. 2016, 7, 1850–1860, doi:10.3762/bjnano.7.177

• behaviour of our nanoalloys. Magnetic characterization First, the magnetic properties of Fe-based clusters embedded in a carbon matrix have been studied by superconducting quantum interference device (SQUID) magnetometry experiments and simulations [4][19][20][21]. As illustrated in Figure 8a, the zero

Active and fast charge-state switching of single NV centres in diamond by in-plane Al-Schottky junctions

• Christoph Schreyvogel,
• Vladimir Polyakov,
• Sina Burk,
• Helmut Fedder,
• Andrej Denisenko,
• Felipe Fávaro de Oliveira,
• Ralf Wunderlich,
• Jan Meijer,
• Verena Zuerbig,
• Jörg Wrachtrup and
• Christoph E. Nebel

Beilstein J. Nanotechnol. 2016, 7, 1727–1735, doi:10.3762/bjnano.7.165

• optically detected magnetic resonance [3] at ambient conditions. Due to these outstanding properties it can be used for applications such as single-spin magnetometry [4], imaging in life science [5], quantum computing and quantum cryptography [6][7] at room temperature, i.e., without the need for cryogenic

Antitumor magnetic hyperthermia induced by RGD-functionalized Fe₃O₄ nanoparticles, in an experimental model of colorectal liver metastases

• Oihane K. Arriortua,
• Eneko Garaio,
• Borja Herrero de la Parte,
• Maite Insausti,
• Luis Lezama,
• Fernando Plazaola,
• Jose Angel García,
• Jesús M. Aizpurua,
• Maialen Sagartzazu,
• Mireia Irazola,
• Nestor Etxebarria,
• Ignacio García-Alonso,
• Alberto Saiz-López and
• José Javier Echevarria-Uraga

Beilstein J. Nanotechnol. 2016, 7, 1532–1542, doi:10.3762/bjnano.7.147

• achieved. The nanoparticles were characterized by transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), electron magnetic resonance (EMR) spectroscopy and magnetic hyperthermia. The nanoparticles present superparamagnetic behavior with very high magnetization values, which yield

Microwave synthesis of high-quality and uniform 4 nm ZnFe₂O₄ nanocrystals for application in energy storage and nanomagnetics

• Christian Suchomski,
• Ben Breitung,
• Ralf Witte,
• Michael Knapp,
• Sondes Bauer,
• Tilo Baumbach,
• Christian Reitz and
• Torsten Brezesinski

Beilstein J. Nanotechnol. 2016, 7, 1350–1360, doi:10.3762/bjnano.7.126

• microscopy and direct-current magnetometry confirm the size uniformity of the nanocrystals, while frequency-dependent alternating-current magnetic susceptibility measurements indicate the presence of a superspin glass state with a freezing temperature of about 22 K. Furthermore, as demonstrated by

• in Figure 4. It reveals a sextet pattern because of the presence of magnetic ordering. This is in accordance with both the magnetometry data below and temperature-dependent Mössbauer spectra shown in Supporting Information File 1, Figure S6. The low-temperature data can be fitted reasonably well with

• ), which is accompanied by the reduction of Fe3+ to Fe2+. The magnetic properties were thoroughly investigated by both direct-current (DC) and alternating-current (AC) superconducting quantum interference device (SQUID) magnetometry. Zero-field-cooled (ZFC) and field-cooled (FC) curves obtained on the as

Customized MFM probes with high lateral resolution

• Óscar Iglesias-Freire,
• Miriam Jaafar,
• Eider Berganza and
• Agustina Asenjo

Beilstein J. Nanotechnol. 2016, 7, 1068–1074, doi:10.3762/bjnano.7.100

• broad range of samples, having a nominal Co layer of either 20 or 25 nm. Single crystalline silicon substrates were placed close to the AFM tips during deposition and used as reference samples for vibrating sample magnetometry (VSM) and AFM/MFM characterization. In all the experiments shown hereafter

Signal enhancement in cantilever magnetometry based on a co-resonantly coupled sensor

• Julia Körner,
• Christopher F. Reiche,
• Thomas Gemming,
• Bernd Büchner,
• Gerald Gerlach and
• Thomas Mühl

Beilstein J. Nanotechnol. 2016, 7, 1033–1043, doi:10.3762/bjnano.7.96

• für Festkörperelektronik, Technische Universität Dresden, 01062 Dresden, Germany 10.3762/bjnano.7.96 Abstract Cantilever magnetometry is a measurement technique used to study magnetic nanoparticles. With decreasing sample size, the signal strength is significantly reduced, requiring advances of the

• interplay between the oscillations of the two cantilevers, allowing for a detection of interactions between the sensitive nanocantilever and external influences in the amplitude response curve of the microcantilever. In our magnetometry experiment we used an iron-filled carbon nanotube acting simultaneously

• as nanocantilever and magnetic sample. Measurements revealed an enhancement of the commonly used frequency shift signal by five orders of magnitude compared to conventional cantilever magnetometry experiments with similar nanomagnets. With this experiment we do not only demonstrate the functionality

Thickness dependence of the triplet spin-valve effect in superconductor–ferromagnet–ferromagnet heterostructures

• Daniel Lenk,
• Vladimir I. Zdravkov,
• Jan-Michael Kehrle,
• Günter Obermeier,
• Aladin Ullrich,
• Roman Morari,
• Hans-Albrecht Krug von Nidda,
• Claus Müller,
• Mikhail Yu. Kupriyanov,
• Anatolie S. Sidorenko,
• Siegfried Horn,
• Rafael G. Deminov,
• Lenar R. Tagirov and
• Reinhard Tidecks

Beilstein J. Nanotechnol. 2016, 7, 957–969, doi:10.3762/bjnano.7.88

• values for the splitting of the metallic and oxide cobalt signals, cross-checked with the RBS spectra for plausibility and slightly adapted to yield the best fit to the RBS spectra. Furthermore, we conducted superconducting quantum interference device (SQUID) magnetometry investigations on several SF1NF2

• curves measured by SQUID magnetometry at T = 10 K, where the sample is normal conducting, yield ms values resulting in mat = 0.074μB, 0.080μB, and 0.127μB. Investigations of the magnetic properties of thin films of Co (deposited on W) [68] and Cu40Ni60 (deposited as Cu40Ni60/Cu multilayers) [53], show

Magnetic switching of nanoscale antidot lattices

• Ulf Wiedwald,
• Joachim Gräfe,
• Kristof M. Lebecki,
• Maxim Skripnik,
• Felix Haering,
• Gisela Schütz,
• Paul Ziemann,
• Eberhard Goering and
• Ulrich Nowak

Beilstein J. Nanotechnol. 2016, 7, 733–750, doi:10.3762/bjnano.7.65

• for non-close packed voids in a magnetic film. We present a magnetometry protocol based on magneto-optical Kerr microscopy elucidating the switching modes using first-order reversal curves. The combination of various magnetometry and magnetic microscopy techniques as well as micromagnetic simulations

• comprehensive contribution. We start the discussion with a technical section on the achievements and limitations of magnetic antidot arrays by bottom-up nanosphere lithography and specially developed characterisation and simulation tools. We show that the development of a proper spatially resolving magnetometry

• magnetic properties of in-plane magnetized antidot films. Integral magnetometry averaging over all in-plane angles of the antidots with respect to the external field proves that the system is highly dominated by the local shape anisotropy introduced by the hole sites. We identify two distinct switching

Single-molecule magnet behavior in 2,2’-bipyrimidine-bridged dilanthanide complexes

• Wen Yu,
• Frank Schramm,
• Eufemio Moreno Pineda,
• Yanhua Lan,
• Olaf Fuhr,
• Jinjie Chen,
• Hironari Isshiki,
• Wolfgang Wernsdorfer,
• Wulf Wulfhekel and
• Mario Ruben

Beilstein J. Nanotechnol. 2016, 7, 126–137, doi:10.3762/bjnano.7.15

• was measured using AC, DC and micro-SQUID magnetometry techniques. The homo-dinuclear complexes of Dy(III) and Er(III) show single-molecule magnet behavior featuring hysteresis loops. The [Tb(tmhd)3]2bpm was sublimated on Au(111) surfaces and scanning tunneling microscopy results are presented in this

Paramagnetism of cobalt-doped ZnO nanoparticles obtained by microwave solvothermal synthesis

• Jacek Wojnarowicz,
• Sylwia Kusnieruk,
• Tadeusz Chudoba,
• Stanislaw Gierlotka,
• Witold Lojkowski,
• Wojciech Knoff,
• Malgorzata I. Lukasiewicz,
• Bartlomiej S. Witkowski,
• Anna Wolska,
• Marcin T. Klepka,
• Tomasz Story and
• Marek Godlewski

Beilstein J. Nanotechnol. 2015, 6, 1957–1969, doi:10.3762/bjnano.6.200

• -ray absorption fine structure (EXAFS) spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and with magnetometry using superconducting quantum interference device (SQUID). Irrespective of the Co content, nanoparticles in their initial state present a similar

• compared with two types of reference samples: ZnO NPs and Zn1−xCoxO layers grown by ALD, studied separately [84]. Magnetic investigations The measurement of the magnetic properties of both as-grown and annealed Zn1−xCoxO NPs were performed by a custom-built SQUID magnetometry experiment for the temperature

Radiation losses in the microwave K_u band in magneto-electric nanocomposites

• Talwinder Kaur,
• Sachin Kumar,
• Jyoti Sharma and
• A. K. Srivastava

Beilstein J. Nanotechnol. 2015, 6, 1700–1707, doi:10.3762/bjnano.6.173

• structural, magnetic and radiation absorbance properties of synthesized compounds have been investigated by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), electron spin resonance spectroscopy (ESR), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM

Thermal treatment of magnetite nanoparticles

• Beata Kalska-Szostko,
• Urszula Wykowska,
• Dariusz Satula and
• Per Nordblad

Beilstein J. Nanotechnol. 2015, 6, 1385–1396, doi:10.3762/bjnano.6.143

• expectations and hematite formation [36]. SQUID magnetometry The superconducting quantum interference device (SQUID) experiments were performed in a magnetic field of 50 Oe in the temperature range 10–300 K using zero-field cooled (ZFC) and field cooled (FC) measurement protocols. In the ZFC protocol, the

Silica micro/nanospheres for theranostics: from bimodal MRI and fluorescent imaging probes to cancer therapy

• Shanka Walia and
• Amitabha Acharya

Beilstein J. Nanotechnol. 2015, 6, 546–558, doi:10.3762/bjnano.6.57

• fluorescence spectroscopy, XRD, FTIR and SQUID magnetometry. The in vitro studies on bone-marrow-derived polymorphonuclear neutrophils (BM-PMNs) suggested that these nanoparticles exert toxic effects only at high concentrations. In a similar way, Chen et al. [25] synthesized FITC-conjugated mesoporous

• TEOS and finally amine functionalization was achieved by using APS. At last MPA-activated CdTe QDs were incorporated into a silica shell containing Fe3O4 NPs. The synthesized NPs were characterized by XRD, TEM, photoluminescence spectroscopy and magnetometry studies. In powder XRD, six diffraction

Influence of the supramolecular architecture on the magnetic properties of a Dy^III single-molecule magnet: an ab initio investigation

• Julie Jung,
• Olivier Cador,
• Kevin Bernot,
• Fabrice Pointillart,
• Javier Luzon and
• Boris Le Guennic

Beilstein J. Nanotechnol. 2014, 5, 2267–2274, doi:10.3762/bjnano.5.236

• , France Instituto de Ciencia de Materiales de Aragon, CSIC–Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain Centro Universitario de la Defensa, Academia General Militar, Zaragoza, Spain 10.3762/bjnano.5.236 Abstract Single-crystal angular-resolved magnetometry and wavefunction-based

• well-known architecture [23][24] that can be optimized for grafting [25][26] the magnetic properties of the molecular object can be kept at the surface [27][28]. This is a tremendous breakthrough in magnetic molecular science that opens the way to molecular surface magnetometry [29]. However, in a

• -crystal magnetometry, low temperature luminescence, and wavefunction-based ab initio calculations, has demonstrated that subtle modification of the DyIII environment such as the rotation of the water molecule is enough to be the driving force of the easy-axis orientation in such a molecule [40

Hybrid spin-crossover nanostructures

• Carlos M. Quintero,
• Gautier Félix,
• Iurii Suleimanov,
• José Sánchez Costa,
• Gábor Molnár,
• Lionel Salmon,
• William Nicolazzi and
• Azzedine Bousseksou

Beilstein J. Nanotechnol. 2014, 5, 2230–2239, doi:10.3762/bjnano.5.232

• later validated using magnetometry. For this purpose, 3 nm thick, organic copolymer, ferroelectric polyvinylidene fluoride trifluoroethylene films (PVDF:TrFE, 70:30) were deposited on graphite substrates using the Langmuir–Blodgett technique (Figure 8). Then, an up or down ferroelectric polarization

PEGylated versus non-PEGylated magnetic nanoparticles as camptothecin delivery system

• Paula M. Castillo,
• Mario de la Mata,
• Maria F. Casula,
• José A. Sánchez-Alcázar and
• Ana P. Zaderenko

Beilstein J. Nanotechnol. 2014, 5, 1312–1319, doi:10.3762/bjnano.5.144

• particular, the average size determined by line profile analysis is 11.0 ± 1.0 nm, in good agreement with the TEM data. The USM sample readily responds to an external magnet and the main magnetic parameters, as derived by SQUID magnetometry characterisation, are summarised in Table 1. ZFC-FC magnetisation

• incubated at 37 °C for 48 h. More than 100 cells were examined for each experimental condition. P < 0.05 significant differences with respect to control cells. Carbodiimide-mediated covalent attachment of PEG to USM-Suc. Main magnetic parameters as derived for the USM sample by SQUID magnetometry: Maximum

In situ monitoring magnetism and resistance of nanophase platinum upon electrochemical oxidation

• Eva-Maria Steyskal,
• Stefan Topolovec,
• Stephan Landgraf,
• Heinz Krenn and
• Roland Würschum

Beilstein J. Nanotechnol. 2013, 4, 394–399, doi:10.3762/bjnano.4.46

• gained by means of a direct comparison of the charge-induced response of two different properties, namely electrical resistance and magnetic moment. For this purpose, four-point resistance measurements and SQUID magnetometry were performed under identical in situ electrochemical control focussing on the

• four-point geometry with a Keithley 2400 multimeter using the outer contact pair for current supply and the inner contact pair for voltage measurement. SQUID magnetometry was performed in a MPMS-XL-7 device (Quantum Design) at a constant magnetic field of 5 kOe upon in situ electrochemical charging

• resistance variation were found by chronoamperometry and cyclic voltammetry. The combination of SQUID magnetometry and in situ cyclic voltammetry opens up attractive potentials for studying nanophase materials under full electrochemical control. Steady-state cyclic voltammograms (CVs) of porous

Tuning the properties of magnetic thin films by interaction with periodic nanostructures

• Ulf Wiedwald,
• Felix Haering,
• Stefan Nau,
• Carsten Schulze,
• Herbert Schletter,
• Denys Makarov,
• Alfred Plettl,
• Karsten Kuepper,
• Manfred Albrecht,
• Johannes Boneberg and
• Paul Ziemann

Beilstein J. Nanotechnol. 2012, 3, 831–842, doi:10.3762/bjnano.3.93

• magnetization. The impact of the particles on the magnetic switching behavior is measured by both integral magnetometry and magnetic microscopy techniques. We observe enhanced coercive fields while the switching field distribution is broadened compared to thin-film reference samples. It appears possible to

• switching in percolated Fe films The impact of such percolated structures as a function of thickness t, the remaining diameter of particles d and the average center-to-center distance a on the magnetic reversal was investigated by integral superconducting quantum interference device (SQUID) magnetometry

• characterization techniques, such as SQUID magnetometry, it is convenient to determine the coercive field HC as a function of the geometric parameters t, d, and a of the samples, as shown in Figure 5b–d, respectively. In panel (b) HC is displayed as a function of the film thickness t for different remaining

Focused electron beam induced deposition: A perspective

• Michael Huth,
• Fabrizio Porrati,
• Christian Schwalb,
• Marcel Winhold,
• Roland Sachser,
• Maja Dukic,
• Jonathan Adams and
• Georg Fantner

Beilstein J. Nanotechnol. 2012, 3, 597–619, doi:10.3762/bjnano.3.70

• the field of focused electron beam induced deposition. Keywords: atomic force microscopy; binary systems; electron beam induced deposition; granular metals; micro Hall magnetometry; radiation-induced nanostructures; strain sensing; Review Introduction Focused electron beam induced deposition (FEBID

Improvement of the oxidation stability of cobalt nanoparticles

• Celin Dobbrow and
• Annette M. Schmidt

Beilstein J. Nanotechnol. 2012, 3, 75–81, doi:10.3762/bjnano.3.9

• to 20 days from synthesis, and were immediately investigated with respect to their magnetic properties by vibrating sample magnetometry (VSM). In addition to the dispersions, the dried powders of selected preparations were investigated. The magnetization curves of all toluene-based particle charges

Nanoscaled alloy formation from self-assembled elemental Co nanoparticles on top of Pt films

• Luyang Han,
• Ulf Wiedwald,
• Johannes Biskupek,
• Kai Fauth,
• Ute Kaiser and
• Paul Ziemann

Beilstein J. Nanotechnol. 2011, 2, 473–485, doi:10.3762/bjnano.2.51

• formation of a CoPt phase with strongly increased magnetic anisotropy compared to pure Co. At higher temperatures, however, the Co atoms diffuse into a nearby surface region where Pt-rich compounds are formed, as shown by element-specific microscopy. Keywords: alloy; Co; CoPt; epitaxy; HRTEM; magnetometry

• alloy formation by X-ray absorption spectroscopy and SQUID magnetometry. The excellent sensitivity of SQUID magnetometers can be exploited, at suitably selected temperatures, to detect the magnetic response corresponding to the Co particles and nanoscale alloys. X-ray magnetic circular dichroism (XMCD

• additionally confirms the lateral spread of Co atoms. Additional in-plane hysteresis loops were measured by SQUID magnetometry for 7 nm Co NPs on Pt(111) films after different annealing steps. Note that each hysteresis loop was measured on a separate sample to exclude any effect of the thin SiO cover layer

Effect of large mechanical stress on the magnetic properties of embedded Fe nanoparticles

• Srinivasa Saranu,
• Sören Selve,
• Ute Kaiser,
• Luyang Han,
• Ulf Wiedwald,
• Paul Ziemann and
• Ulrich Herr

Beilstein J. Nanotechnol. 2011, 2, 268–275, doi:10.3762/bjnano.2.31

• first introduce the experimental method for applying stress and provide evidence for the presence of large biaxial stresses. Then we present results from SQUID magnetometry of Fe nanoparticles in the stressed and stress-free state for the same sample over a range of temperatures. Results and Discussion