Ferromagnetic behaviour of ZnO: the role of grain boundaries

• Boris B. Straumal,
• Svetlana G. Protasova,
• Andrei A. Mazilkin,
• Eberhard Goering,
• Gisela Schütz,
• Petr B. Straumal and
• Brigitte Baretzky

Beilstein J. Nanotechnol. 2016, 7, 1936–1947, doi:10.3762/bjnano.7.185

• SQUID interferometer (Quantum Design MPMS-7 and MPMS-XL) in the external magnetic field applied parallel to the sample plane. The diamagnetic signal from a sample holder and a substrate was accurately subtracted from the magnetization curves. In Figure 3 the magnetization curves are plotted for pure ZnO

• . The drastic increase of the total solubility of dopants in ZnO with decreasing grain size has been also observed. It is explained by the multilayer GB segregation. Ferromagnetic (full symbols) and paramagnetic or diamagnetic properties (open symbols) of (a) pure zinc oxide [7] and ZnO doped with (b

Multiwalled carbon nanotube hybrids as MRI contrast agents

• Nikodem Kuźnik and
• Mateusz M. Tomczyk

Beilstein J. Nanotechnol. 2016, 7, 1086–1103, doi:10.3762/bjnano.7.102

• and increases diffusion and mobility. These effects are partially taken into account in the diamagnetic factor of Equation 1 (Ti,diam). However, they also affect relaxivity in a non-linear way. Finally, the medium used for the preparation of dispersion samples and the following dilutions have multiple

• . Relaxivity is intended to express the acceleration effect of the appropriate relaxation time (T1 or T2) caused by interaction with a non-diamagnetic agent. Now, for complexes with low molecular mass molarity is an easy and convenient value to operate with. This way of calculating relaxivity was translated

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

• realized. The second subscript of the parameters denotes the corresponding material. Moreover, m0 is a small offset of the magnetic moment scale and s is the slope of the superposition of the diamagnetic and paramagnetic contribution from the substrate and the antiferromagnet [64], respectively. The

• the F1 = Cu41Ni59 and F2 = Co layers; CR: crossed configuration of the magnetic moments of F1- and F2 layers). The diamagnetic contribution of the silicon substrate is subtracted (only in (b)). Here, cgs emu units are used. In SI units, it is 1 emu = 10−3 A·m2 and 1 Oe = 103/(4π) A/m [63], so that

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

• an oscillating magnetic field of 3.5 Oe. All data were corrected for diamagnetic contributions from the eicosane and core diamagnetism, estimated using Pascal’s constants [31]. Low temperature (0.03–5 K) magnetization measurements were performed on single crystals using a micro-SQUID apparatus at

A facile method for the preparation of bifunctional Mn:ZnS/ZnS/Fe₃O₄ magnetic and fluorescent nanocrystals

• Houcine Labiadh,
• Tahar Ben Chaabane,
• Romain Sibille,
• Lavinia Balan and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2015, 6, 1743–1751, doi:10.3762/bjnano.6.178

• could be related to the quantum confinement effects of nanocrystals and to the diamagnetic contribution of the ZnS core. At 2 K, all bifunctional nanoparticles exhibited hysteresis with remnance magnetization, MR, at 9 T and coercivity, HC, indicating a dominant ferromagnetic nature of the iron oxide

Synthesis, characterization and in vitro biocompatibility study of Au/TMC/Fe₃O₄ nanocomposites as a promising, nontoxic system for biomedical applications

• Hanieh Shirazi,
• Maryam Daneshpour,
• Soheila Kashanian and
• Kobra Omidfar

Beilstein J. Nanotechnol. 2015, 6, 1677–1689, doi:10.3762/bjnano.6.170

• /Fe3O4 and Au/TMC/Fe3O4 nanoparticles was 20.77 and 56.13 emu/g, respectively. While all synthesized nanoparticles exhibited good magnetic properties, even in the presence of polymers and Au nanoparticles, the addition of a diamagnetic layer of chitosan caused a more significant reduction in the magnetic

Magnetic properties of iron cluster/chromium matrix nanocomposites

• Arne Fischer,
• Robert Kruk,
• Di Wang and
• Horst Hahn

Beilstein J. Nanotechnol. 2015, 6, 1158–1163, doi:10.3762/bjnano.6.117

• experiments with Fe/Ag was to study the characteristics of the embedded Fe clusters. Since Ag is diamagnetic no noteworthy magnetic interaction takes place between matrix and the ferromagnetic clusters and it was possible to gain information about, e.g., the size of the embedded clusters via magnetic

• interactions) become dominant. Hysteresis loops were recorded at 5 K after field cooling from 350 K, which is above the TN of Cr (311 K [16]), in an external magnetic field of μ0H = 4.5 T. A linear diamagnetic background originating from the Si substrate as well as the Au layers was subtracted. The coercivity

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

• that in the hybrid nanocomposite material the thick silica coating acts as diamagnetic component. Similarly, Yi et al. [45] reported the synthesis of silica-coated γ-Fe2O3 magnetic NPs and CdSe QDs through a reverse microemulsion approach. The synthesis involved the isolated preparation of magnetic NPs

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

• ]. The easiest way to evidence these supramolecular effects is to design a diamagnetic solid solution in which the sample is present at a doping level [3][4][5][6][7][8][9][10][11][12]. The investigation of such sample shows drastic differences from the bulk and highlights that a “single-molecule” when

Towards bottom-up nanopatterning of Prussian blue analogues

• Virgile Trannoy,
• Marco Faustini,
• David Grosso,
• Sandra Mazerat,
• François Brisset,
• Alexandre Dazzi and
• Anne Bleuzen

Beilstein J. Nanotechnol. 2014, 5, 1933–1943, doi:10.3762/bjnano.5.204

• diamagnetic state into a ferrimagnetic state with a long life time. This photomagnetic effect is interesting for high-density storage since the property of bistability is intrinsically molecular and therefore persists up to molecular scale [5][6][7][8]. These coordination polymers are obtained by a reaction

Spin relaxation in antiferromagnetic Fe–Fe dimers slowed down by anisotropic Dy^III ions

• Valeriu Mereacre,
• Frederik Klöwer,
• Yanhua Lan,
• Rodolphe Clérac,
• Juliusz A. Wolny,
• Volker Schünemann,
• Christopher E. Anson and
• Annie K. Powell

Beilstein J. Nanotechnol. 2013, 4, 807–814, doi:10.3762/bjnano.4.92

• applied external magnetic field of 5 T has been measured for 2 (Figure 4). It confirms the diamagnetic ground state for the Fe2 units. The simulation parameters were the field at the nucleus Beff = 5.0 T, ΔEQ = 0.80 mm/s, δ = 0.47 mm/s, and the asymmetry parameter η = 0.95. The experimental data fit very

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

• and characterize possible structural changes during electrochemical cycling. In 7Li MAS NMR, the reduced material shows a single resonance at +0.5 ppm (Figure 5c), a value characteristic of diamagnetic lithium salts. No signals that could be assigned to metallic lithium and lithium silicide are

Synthesis and thermoelectric properties of Re₃As_6.6In_0.4 with Ir₃Ge₇ crystal structure

• Valeriy Y. Verchenko,
• Anton S. Vasiliev,
• Alexander A. Tsirlin,
• Vladimir A. Kulbachinskii,
• Vladimir G. Kytin and
• Andrei V. Shevelkov

Beilstein J. Nanotechnol. 2013, 4, 446–452, doi:10.3762/bjnano.4.52

• into plastic capsules. Measurements were performed with the VSM setup of Quantum Design PPMS in external fields of 0.1, 0.5, 1, 2, and 5 T. To estimate the diamagnetic contribution from the sample holder, an empty capsule was measured under the same conditions. Results and Discussion Synthesis, sample

Ferromagnetic behaviour of Fe-doped ZnO nanograined films

• Boris B. Straumal,
• Svetlana G. Protasova,
• Andrei A. Mazilkin,
• Thomas Tietze,
• Eberhard Goering,
• Gisela Schütz,
• Petr B. Straumal and
• Brigitte Baretzky

Beilstein J. Nanotechnol. 2013, 4, 361–369, doi:10.3762/bjnano.4.42

• broadening was performed by using the Scherrer equation [21]. The magnetic properties were measured on a superconducting quantum interference device (Quantum Design MPMS-7 and MPMS-XL). The magnetic field was applied parallel to the sample plane (“in plane”). The diamagnetic background signals, generated by

• diagram in Figure 4. Second, the coarse-grained samples synthesised by the conventional powder sintering method, bulk single crystals or single-crystalline films are always diamagnetic or paramagnetic [48][49][50][51][52][53][54][55]. They are positioned in the left part of the diagram in Figure 4. In

• “liquid ceramics” method. FM (full symbols) and para- or diamagnetic (open symbols) behaviour of Fe-doped ZnO in dependence on the specific GB area, sGB, the ratio of GB area to volume, at different preparation temperatures T. A vertical line marks the estimated threshold value sth. The enlarged symbol

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

• used for preservation in ambient conditions after in-situ annealing. Contrary to XMCD, SQUID magnetometry measures the total magnetic moment of the sample, i.e., the NPs, the paramagnetic Pt film, the SiO protective layer and the diamagnetic MgO(100) substrate. Usually the magnetic response of the

• support easily overwhelms the total magnetic moment of the tiny amount of ferromagnetic material in the NPs. In the present system one can benefit from the paramagnetic response of the Pt(111) film and paramagnetic impurities in MgO compensating the diamagnetic signal of the substrate. Since the

• : 30 min). The lines are given as guides to the eye. (a) In-plane hysteresis loops measured by SQUID magnetometry at T = 29 K, i.e., close to the compensation temperature of the diamagnetic MgO substrate and the paramagnetic Pt(111) film on top. In (b), the Henkel plots for three annealing steps are

Preparation and characterization of supported magnetic nanoparticles prepared by reverse micelles

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

Beilstein J. Nanotechnol. 2010, 1, 24–47, doi:10.3762/bjnano.1.5

• investigating the magnetic properties of NPs prepared by reverse micelles poses is having to deal with small magnetic signals composed of contributions from both, the NPs as well as the supporting mostly diamagnetic substrate. For example, 8 nm Co NPs with a bulk saturation magnetization of 1.73 µB per atom and

• interparticle distances of 100 nm on a 5 × 5 mm2 substrate produce a total magnetic moment of only 10–9 Am2 (10–6 emu). Although state-of-the-art SQUID-magnetometry is able to detect the related small signals, the response of the diamagnetic substrate has to be taken into account as well delivering for the

• typically applied external fields signals of the same order of magnitude as the particles, however, of opposite sign. Thus, the magnetic responses from the NPs and the substrate cancel each other at external fields between 20–200 mT depending on the volume of the substrate and diamagnetic susceptibility