Influence of dielectric layer thickness and roughness on topographic effects in magnetic force microscopy

• Alexander Krivcov,
• Jasmin Ehrler,
• Marc Fuhrmann,
• Tanja Junkers and
• Hildegard Möbius

Beilstein J. Nanotechnol. 2019, 10, 1056–1064, doi:10.3762/bjnano.10.106

• magnetic field of the probe with a magnetic moment of 3·10−16 A·m2 is sufficient to induce a magnetic moment at lift heights up to 150 nm in superparamagnetic nanoparticles with 10 nm diameter. This results in attractive forces and, thus, negative phase shifts in MFM measurements. Therefore the magnetic

• magnetized sphere [20][22][23]: where Q is the quality factor of the cantilever, k is the spring constant, µ0 is the vacuum permeability, mp is the magnetic moment of the nanoparticle, mtip is the magnetic moment of the tip, and a is the distance between the two dipoles and is shown schematically in Figure 5

• and SPION. Figure 7 shows the phase shift as a function of lift height for substrates with different dielectric layer thicknesses ranging from 0 nm (no layer) up to 380 nm. The measurements are carried out with a tip with high magnetic moment (ASYMFM-HM tip) in order to obtain a strong magnetic

Electronic and magnetic properties of doped black phosphorene with concentration dependence

• Ke Wang,
• Hai Wang,
• Min Zhang,
• Yan Liu and
• Wei Zhao

Beilstein J. Nanotechnol. 2019, 10, 993–1001, doi:10.3762/bjnano.10.100

• for the Si-doped phosphorene with 2 × 2 × 1 supercell and a dopant content of 6.25%. The magnetic moment induced by 3p orbit–spin splitting increases with the in-plane size of the supercell, and the largest magnetic moment can be found in 4 × 4 × 1 and 5 × 5 × 1 supercells. These findings offer an

• . According to the first-principles calculations, we find that the magnetic moment of doped phosphorene increases significantly with increasing the in-plane size of the supercell and reducing the impurity concentration, while the bandgap of doped phosphorene is opened due to the shrinking of the charge

• magnetic moment In order to identify the magnetism of Si- and S-doped phosphorenes, the energy difference ΔEsp was calculated as follows [24][25][26]: where Esp and Ensp are the energy of doped phosphorene computed with spin polarization and without polarization, respectively. According to the lowest

Magnetic field-assisted assembly of iron oxide mesocrystals: a matter of nanoparticle shape and magnetic anisotropy

• Julian J. Brunner,
• Marina Krumova,
• Helmut Cölfen and
• Elena V. Sturm (née Rosseeva)

Beilstein J. Nanotechnol. 2019, 10, 894–900, doi:10.3762/bjnano.10.90

• driven by competing of two types of anisotropic interactions caused by particle shape (i.e., faceting) and orientation of the magnetic moment (i.e., easy axes: <111>magnetite). Hence, these findings provide a fundamental understanding of formation mechanisms and structuring of mesocrystals built up from

• ]. Due to the superparamagnetic property of the magnetite nanocrystals, their assembly process can be strongly influenced by an external magnetic field which is then labelled as “directed assembly” [21]. The magnetic moment of the magnetic nanocrystals tends to align along a certain crystallographic axis

• shape (i.e., faceting), while the alignment along the magnetic field lines is driven by the orientation of the magnetic moment of the nanoparticles (i.e., easy axis: <111>magnetite). Future work applying varying magnetic field strength will show the structural variety of the mesocrystals, which is

Co-doped MnFe₂O₄ nanoparticles: magnetic anisotropy and interparticle interactions

• Bagher Aslibeiki,
• Parviz Kameli,
• Hadi Salamati,
• Giorgio Concas,
• Maria Salvador Fernandez,
• Alessandro Talone,
• Giuseppe Muscas and
• Davide Peddis

Beilstein J. Nanotechnol. 2019, 10, 856–865, doi:10.3762/bjnano.10.86

• general increment of the anisotropy. The Co2+ ions produced a marked magneto-crystalline contribution to the anisotropy in the spinel structure, more than Mn2+ and Mn3+ ions. Indeed, the crystal field does not entirely quench its orbital magnetic moment, allowing for a spin–orbital coupling responsible

• interactions belongs to C0, and decreases with respect to the Co content with an exponential decay. We roughly estimated the dipolar interaction energy as [53]: where µ is the magnetic moment of the single particle and d the distance between particle centers (considered as point dipole), calculated as the

Periodic Co/Nb pseudo spin valve for cryogenic memory

• Nikolay Klenov,
• Yury Khaydukov,
• Sergey Bakurskiy,
• Roman Morari,
• Igor Soloviev,
• Vladimir Boian,
• Thomas Keller,
• Mikhail Kupriyanov,
• Anatoli Sidorenko and
• Bernhard Keimer

Beilstein J. Nanotechnol. 2019, 10, 833–839, doi:10.3762/bjnano.10.83

• ferromagnetically aligned segment in the AP aligned lattice, this will lead to a substantial increase of the total magnetic moment (see the red dot in Figure 4b) which is in strong disagreement with the SQUID data. Thus we rule out the presence of stacking faults in our sample. Thus in this work we considered the

• shown by solid lines in Figure 3a. (b) Hysteresis loop measured by SQUID magnetometry (solid line). The black dot indicates the magnetic moment of the sample which is obtained by the integration of the depth profiles depicted in (a). The red dot shows the magnetic moment at H = 30 Oe expected if one P

The effect of translation on the binding energy for transition-metal porphyrines adsorbed on Ag(111) surface

• Luiza Buimaga-Iarinca and
• Cristian Morari

Beilstein J. Nanotechnol. 2019, 10, 706–717, doi:10.3762/bjnano.10.70

• exception. For FePP we obtain a magnetic moment of 4μB in the isolated molecule, while the adsorbed molecule has a magnetic moment of 1.69μB. The magnetic moments for different TMPP molecules are separated by approximately 1μB as a consequence of the gradual filling of the 3d orbitals. The largest magnetic

• moment is obtained for MnPP. The result is close to the result predicted by Hund’s rules for a single atom (5μB). The smallest value of zero was obtained for NiPP. In this case, there is only a change of the magnetic moment as a result of changing the adsorption site. At the low-symmetry “i” points, the

• . Consequently, the spin-down states are occupied and the system has a non-zero magnetic moment. This effect is reversed for the deep orbital at −3.7 eV, which is localized (i.e., no coupling to energy bands of Ag) in the “i” states, while there is a clear interaction with the metallic substrate at the bridge

Hydrogen-induced plasticity in nanoporous palladium

• Markus Gößler,
• Eva-Maria Steyskal,
• Markus Stütz,
• Norbert Enzinger and
• Roland Würschum

Beilstein J. Nanotechnol. 2018, 9, 3013–3024, doi:10.3762/bjnano.9.280

• ][2][3], resistance [4][5][6], magnetic moment [5][7], optical transmission [8] and selective chemical transport [9] have been reported in recent years, apart from the mechanical properties described below. Dealloying, a selective dissolution process, has become an established technique to produce

Size limits of magnetic-domain engineering in continuous in-plane exchange-bias prototype films

• Alexander Gaul,
• Daniel Emmrich,
• Timo Ueltzhöffer,
• Henning Huckfeldt,
• Hatice Doğanay,
• Johanna Hackl,
• Muhammad Imtiaz Khan,
• Daniel M. Gottlob,
• Gregor Hartmann,
• André Beyer,
• Dennis Holzinger,
• Slavomír Nemšák,
• Claus M. Schneider,
• Armin Gölzhäuser,
• Günter Reiss and
• Arno Ehresmann

Beilstein J. Nanotechnol. 2018, 9, 2968–2979, doi:10.3762/bjnano.9.276

• , the influence of the demagnetization field leads to the formation of a local, almost flux-closure-like pattern of the magnetic moment distribution. This can be also seen in the simulations particularly for the smaller domains, since there the contribution of the magnetocrystalline anisotropy energy is

• initial EB direction pointing to the left, positive angles imply counterclockwise rotation. (m–o) Magnified view on the smallest domain structures from panels (i–l). Arrows indicate the direction (orientation) and relative value (length) of the local magnetic moment. Simulated distribution of the energy

Magnetic and luminescent coordination networks based on imidazolium salts and lanthanides for sensitive ratiometric thermometry

• Pierre Farger,
• Cédric Leuvrey,
• Mathieu Gallart,
• Pierre Gilliot,
• Guillaume Rogez,
• João Rocha,
• Duarte Ananias,
• Pierre Rabu and
• Emilie Delahaye

Beilstein J. Nanotechnol. 2018, 9, 2775–2787, doi:10.3762/bjnano.9.259

• networks, the luminescent properties can be used to synthesize temperature probes with possible applications in the aerospace area, safety and health [17][18]. Beside luminescent properties, lanthanide ions exhibit large magnetic moment and strong magnetic anisotropy, which might have potential

Contactless photomagnetoelectric investigations of 2D semiconductors

• Marian Nowak,
• Marcin Jesionek,
• Barbara Solecka,
• Piotr Szperlich,
• Piotr Duka and
• Anna Starczewska

Beilstein J. Nanotechnol. 2018, 9, 2741–2749, doi:10.3762/bjnano.9.256

• importance. Results: Here we show a contactless method for determining these parameters in 2D semiconductors that is based on the photomagnetoelectric (PME) effect (also known as the photoelectromagnetic effect). We present calculated dependences of the PME magnetic moment, evoked in 2D Corbino configuration

• because of the Lorentz force. In this case, they flow around the illuminated region (Figure 1). The circulating PME-Corbino current evokes the PME magnetic moment. In the induction method of measurements, the varying PME magnetic moment caused by intermittent illumination induces an AC voltage in

• appropriate measuring coils. The formula describing the PME magnetic moment, evoked in a bulk semiconductor wafer illuminated by weakly absorbed radiation as a function of τ, sample thickness, and surface recombination velocity (s) of the illuminated (front) and unilluminated (back) surfaces were previously

Disorder in H⁺-irradiated HOPG: effect of impinging energy and dose on Raman D-band splitting and surface topography

• Lisandro Venosta,
• Noelia Bajales,
• Sergio Suárez and
• Paula G. Bercoff

Beilstein J. Nanotechnol. 2018, 9, 2708–2717, doi:10.3762/bjnano.9.253

• separation between each Raman measurement on the irradiated HOPG region (the geometrical centre of the sample) was also chosen as 1 µm, in order to have enough statistics on the defective area. After Raman measurements, the magnetic moment as a function of the applied field was measured at 4 K with a Quantum

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

• ], while the total magnetic moment of isolated Mn atoms can be substantially smaller than that of MnSb inclusions. The temperature dependence of ΔRH is more complicated. But in the present case of a large AHE contribution, MR and AHE itself can strongly affect RH through the relations of conductivity and

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

• extremely low associated magnetic moment needing peculiar experimental configurations and specific ultra-sensitive magnetic sensors such as micro-SQUID (superconducting quantum interference device) detectors [26]. Arrays of such nanowires (thousands of single elements) can be investigated by usual SQUID

• involving the field dependence of the average magnetic moment per formula unit were obtained (as exemplified in Figure 4 for the case of samples with 54 and 92 atom % of Ni). Average magnetic moments per Ni atom of 0.38µB, 0.22µB and 0.12µB (corresponding to MS values of 3.0·105, 1.7·105 and 0.9·105 A·m−1

• values are obtained for saturation magnetization values close to 6·105 A·m−1. It is worth mentioning that this value is much larger than the typical value of bulk Ni at 300 K of about 4.8·105 A·m−1 with a magnetic moment for Ni of about 0.75μB. This is a surprising result inferring specific electronic

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

• interaction between spin current and AF magnetic moment. Figure 2 shows characteristic FMR spectra of the trilayer sample series recorded at 9 GHz. For tIrMn ≤ 6 nm, only one spectral peak is observed. It indicates the presence of a long-range dynamic exchange coupling between the two CoFeB layers across the

Free-radical gases on two-dimensional transition-metal disulfides (XS₂, X = Mo/W): robust half-metallicity for efficient nitrogen oxide sensors

• Chunmei Zhang,
• Yalong Jiao,
• Fengxian Ma,
• Sri Kasi Matta,
• Steven Bottle and
• Aijun Du

Beilstein J. Nanotechnol. 2018, 9, 1641–1646, doi:10.3762/bjnano.9.156

• discussions on the adsorption of NO and NO2 on XS2 (X = Mo, W), as NO and NO2 are paramagnetic free radicals. Most other gas molecules, such as NH3, CO and CO2, have no magnetic moment. Monolayer XS2 (X = Mo, W) have a hexagonal configuration, where three pairs of S atoms are anchored on one X atom and form

• alternating corners (S–X–S) in a honeycomb network. Figure 1 illustrates the top and side view structures of the favorable NO and NO2 adsorption position on the 3 × 3 supercell of XS2 (X = Mo, W), and Table 1 summarizes the corresponding values of adsorption energy and magnetic moment. The equilibrium height

• NO2 are free radical gas molecules with a magnetic moment of 1µB. To fully understand the NOx adsorption mechanism, it is important to understand the interactions between the monolayer and the adsorbate molecules. Investigations [8][28] revealed that charge transfer occurs from the XS2 (X = Mo, W

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

• the superparamagnetic state is observed. Above a certain critical temperature, called the blocking temperature, the thermal energy induces rapid fluctuations of the nanoparticle’s magnetic moment relative to the time of observation [1][2]. Superparamagnetic nanoparticles do not show remanence and

• heating of the magnetic nanoparticles in the AC field is a consequence of the magnetic moment relaxation of the magnetic nanoparticles [35][36]. The heating and the characteristic value related to the heating ability, called the specific power loss (SLP), will be the greatest when the frequency of the AC

• lower (a) and higher (b) magnification and NC-3 at lower (c) and higher (d) magnification. (a) Room-temperature magnetization curves of the NP-RA nanoparticles and nanocomposites. (b) Temperature dependence of the magnetic moment under zero-field cooling conditions for the NP-RA nanoparticles and

Interplay between pairing and correlations in spin-polarized bound states

• Szczepan Głodzik,
• Aksel Kobiałka,
• Anna Gorczyca-Goraj,
• Andrzej Ptok,
• Grzegorz Górski,
• Maciej M. Maśka and
• Tadeusz Domański

Beilstein J. Nanotechnol. 2018, 9, 1370–1380, doi:10.3762/bjnano.9.129

• λ and it has experimentally observable consequences in the magnetization induced near the impurity site. For weak magnetic scattering |J| < Jc the impurity is partly screened, whereas for stronger couplings |J| > Jc the impurity polarizes its neighborhood in the direction of its own magnetic moment

Single-crystalline FeCo nanoparticle-filled carbon nanotubes: synthesis, structural characterization and magnetic properties

• Rasha Ghunaim,
• Maik Scholz,
• Christine Damm,
• Bernd Rellinghaus,
• Rüdiger Klingeler,
• Bernd Büchner,
• Michael Mertig and
• Silke Hampel

Beilstein J. Nanotechnol. 2018, 9, 1024–1034, doi:10.3762/bjnano.9.95

• -defined manner without the need of vigorous conditions. Depending on the chosen procedure, we were able to influence the filling yield, size, magnetic moment, coercivity, as well as the appearance of the sample in terms of particles inside CNTs to those on the outer surface. Tuning several parameters

Anchoring Fe₃O₄ nanoparticles in a reduced graphene oxide aerogel matrix via polydopamine coating

• Błażej Scheibe,
• Radosław Mrówczyński,
• Natalia Michalak,
• Karol Załęski,
• Michał Matczak,
• Mateusz Kempiński,
• Zuzanna Pietralik,
• Mikołaj Lewandowski,
• Stefan Jurga and
• Feliks Stobiecki

Beilstein J. Nanotechnol. 2018, 9, 591–601, doi:10.3762/bjnano.9.55

• , which is due to additional contribution of PDA to the sample volume [65]. The agglomeration of magnetic nanoparticles has a direct effect on any measurement performed on NPs when extracting quantitative parameters, such as, e.g., the magnetic moment value [66]. The interparticle distance affects the

• saturation magnetization of magnetic nanoparticles, as the strength of the magnetic moment interaction depends on the interparticle distance [67]. Therefore, the compression of nanoparticles in the c-rGO-PDA@Fe3O4 aerogel sample led to the increase of the saturation magnetization. Figure 7b presents ZFC and

Ferrocholesteric–ferronematic transitions induced by shear flow and magnetic field

• Dmitriy V. Makarov,
• Alexander A. Novikov and
• Alexander N. Zakhlevnykh

Beilstein J. Nanotechnol. 2017, 8, 2552–2561, doi:10.3762/bjnano.8.255

• ). F3 is the bulk density of the interaction energy of the magnetic field H with the magnetic moment μ = MSvpn of the particles (the dipole mechanism of the magnetic field effect on an FC). F4 is the contribution of the entropy of mixing of an ideal solution of magnetic particles to the free energy of a

Adsorption of iron tetraphenylporphyrin on (111) surfaces of coinage metals: a density functional theory study

• Hao Tang,
• Nathalie Tarrat,
• Véronique Langlais and
• Yongfeng Wang

Beilstein J. Nanotechnol. 2017, 8, 2484–2491, doi:10.3762/bjnano.8.248

• state, which will be used as reference for the total energy comparison from now on. At the three other adsorption sites (hollow-hcp, top and bridge), the energy is higher by 0.04 eV. The magnetic moment of HS state is 4.18 ± 0.05 μB for these four sites. At hollow-fcc, the IS state energy is found to be

• higher by 0.07 eV than the HS state, while at the three other sites (hollow-hcp, top and bridge) the IS energies are 0.10 eV larger than the reference. The magnetic moment of the IS state on these sites is 2.24 ± 0.02 μB. The molecule–surface distance is defined as the difference between the average z

• (111) is similar to that on Ag(111). Relative energy, E0, and magnetic moment, μ, of S4, D2d and C2h conformations in the states S = 1 and S = 2. The reference energy is that of the HS D2d conformation. Relative energy, E0, magnetic moment, μ, and Fe–surface distance, dFe-surface, of FeTPP (in

Dynamic behavior of a nematic liquid crystal mixed with CoFe₂O₄ ferromagnetic nanoparticles in a magnetic field

• Emil Petrescu,
• Cristina Cirtoaje and
• Cristina Stan

Beilstein J. Nanotechnol. 2017, 8, 2467–2473, doi:10.3762/bjnano.8.246

• systems is: where K1, K2 and K3 are twist, splay and bend elastic constants, Ms is saturation magnetization, V is the particle volume, a is the average particle diameter, m is the magnetic moment of the particles, W is the surface density of the interfacial energy on the nematic boundary of the particles

Magnetic properties of optimized cobalt nanospheres grown by focused electron beam induced deposition (FEBID) on cantilever tips

• Soraya Sangiao,
• César Magén,
• Darius Mofakhami,
• Grégoire de Loubens and
• José María De Teresa

Beilstein J. Nanotechnol. 2017, 8, 2106–2115, doi:10.3762/bjnano.8.210

• nanosphere [11]. From the maximal relative variation of the cantilever frequency (1.2% in Figure 6a) and knowing the cantilever spring constant and the second spatial derivative of the magnetic field ((1.5 ± 0.3) × 109 T/m2) in which the measurements are operated, one can estimate the magnetic moment of the

• standard laser deflection technique is used to monitor the displacement of the cantilever. Its resonance frequency is tracked using a piezoelectric bimorph and a feedback electronic circuit based on a phase lock loop. The relative frequency shift due to the force acting on the magnetic moment m of the

Electronic structure, transport, and collective effects in molecular layered systems

• Torsten Hahn,
• Tim Ludwig,
• Carsten Timm and
• Jens Kortus

Beilstein J. Nanotechnol. 2017, 8, 2094–2105, doi:10.3762/bjnano.8.209

• similar fluorinated copper phthalocyanine (F16CoPc), has demonstrated the occurrence of hybridization [11]. It was proved that a local charge transfer which affects only the transition-metal centers changes the charge state of the transition metal and is directly related to a change of its magnetic moment

• density of states as obtained from the DFT calculations. While the electronic structure of CoPc and F16CoPc is qualitative similar after surface contact, the manganese center in the F16CoPc/MnPc yields a larger local magnetic moment and more strongly occupied metal 3d states close to the Fermi level. Both

Charge transfer from and to manganese phthalocyanine: bulk materials and interfaces

• Florian Rückerl,
• Daniel Waas,
• Bernd Büchner,
• Martin Knupfer,
• Dietrich R. T. Zahn,
• Francisc Haidu,
• Torsten Hahn and
• Jens Kortus

Beilstein J. Nanotechnol. 2017, 8, 1601–1615, doi:10.3762/bjnano.8.160

• ][8]. Phthalocyanine molecules can harbor a number of metal ions, in particular transition-metal ions such as cobalt, iron or manganese. A special characteristic of transition-metal centered phthalocyanines is, that transition-metal ions often are characterized by a magnetic moment, and therefore such

• possible [43][45][46]. The EELS cross section is proportional to Im(−1/ε) (ε is the dielectric function). In this way, one can investigate valence-band excitations (cf. optical methods) and the element-projected unoccupied density of states. Also, access to orbital selective occupations and the magnetic

• moment of open shells is accessible. Spectroscopic ellipsometry [47][48][49] measures the change in the light polarization after reflection on a sample surface. This information allows for the determination of the real and the imaginary part of the dielectric function. XAS [42][50] is equivalent to EELS