On the relaxation time of interacting superparamagnetic nanoparticles and implications for magnetic fluid hyperthermia

• Andrei Kuncser,
• Nicusor Iacob and
• Victor E. Kuncser

Beilstein J. Nanotechnol. 2019, 10, 1280–1289, doi:10.3762/bjnano.10.127

• in the static regime, P* can be simply expressed by multiplying the area of the hysteresis loop developed under the amplitude of the AC field with its frequency. However, according to Equation 1, the experimentally obtained SAR values should increase linearly with φ under the condition that P* does

• nanoparticle size can be large enough to open a hysteresis loop), so it becomes really difficult to compare experimental results on SAR with the above-mentioned approach. On the other hand, according to the above-mentioned theory, the out-of-phase component of the susceptibility of interacting nanoparticles

Molecular attachment to a microscope tip: inelastic tunneling, Kondo screening, and thermopower

• Rouzhaji Tuerhong,
• Mauro Boero and
• Jean-Pierre Bucher

Beilstein J. Nanotechnol. 2019, 10, 1243–1250, doi:10.3762/bjnano.10.124

• tips. Interestingly, when the gap resistance is decreased from 2.1 to 0.90 GΩ (blue arrow in Figure 4d), the Kondo temperature TK decreases from 60 to 47 K. Following the hysteresis, when the gap resistance is increased from 2.1 to 2.5 GΩ (red arrow in Figure 4d), the Kondo temperature TK also

Playing with covalent triazine framework tiles for improved CO₂ adsorption properties and catalytic performance

• Giulia Tuci,
• Andree Iemhoff,
• Housseinou Ba,
• Lapo Luconi,
• Andrea Rossin,
• Vasiliki Papaefthimiou,
• Regina Palkovits,
• Jens Artz,
• Cuong Pham-Huu and
• Giuliano Giambastiani

Beilstein J. Nanotechnol. 2019, 10, 1217–1227, doi:10.3762/bjnano.10.121

• profile with a distinctive H2 hysteresis loop in the range of p/p0 = 0.4–0.6. As expected from its longer linker, CTF2 shows an increase of mesoporosity with respect to CTF1 (mesopore volume from 60% to 75% of the total pore volume). Both samples present a high and comparable specific surface area and a

Tailoring the magnetic properties of cobalt ferrite nanoparticles using the polyol process

• Malek Bibani,
• Romain Breitwieser,
• Alex Aubert,
• Vincent Loyau,
• Silvana Mercone,
• Souad Ammar and
• Fayna Mammeri

Beilstein J. Nanotechnol. 2019, 10, 1166–1176, doi:10.3762/bjnano.10.116

• confirm the high crystalline quality of the produced NPs. We pursued our investigations by plotting the variation of the magnetization of these particles as a function of the magnetic field at RT, typically T = 300 K (Figure 6). Low-temperature (T = 10 K) hysteresis behavior is not reported, as it is

Quantitative analysis of annealing-induced instabilities of photo-leakage current and negative-bias-illumination-stress in a-InGaZnO thin-film transistors

• Dapeng Wang and
• Mamoru Furuta

Beilstein J. Nanotechnol. 2019, 10, 1125–1130, doi:10.3762/bjnano.10.112

• . The hysteresis after negative-bias-illumination-stress (NBIS) is quantitatively investigated by using the double-scan mode and a positive gate pulse. Despite the abnormal transfer properties in the low-temperature-treated device, the excited holes are identically trapped at the front interface

• adjacent interfaces. The incident photon energy (>2.7 eV) excites the defect generation and the leakage current increases in the devices regardless of heating temperature. By means of the double-scan mode and a positive gate pulse, the NBIS-caused hysteresis of the TFTs annealed at different temperatures

• formation of the metal-oxide atomic framework, improving the channel layer quality. The notorious I–V hysteresis is regarded as an indicator for the quality of the GI/semiconductor interface. The values of the hysteresis, i.e., the difference of VGS at IDS = 1 pA scanned in the forward and reverse

Scavenging of reactive oxygen species by phenolic compound-modified maghemite nanoparticles

• Małgorzata Świętek,
• Yi-Chin Lu,
• Rafał Konefał,
• Liliana P. Ferreira,
• M. Margarida Cruz,
• Yunn-Hwa Ma and
• Daniel Horák

Beilstein J. Nanotechnol. 2019, 10, 1073–1088, doi:10.3762/bjnano.10.108

• . The superparamagnetism of the γ-Fe2O3 colloid was confirmed by SQUID magnetometry through the absence of remanence and coercivity in the magnetic hysteresis curve (Figure 3c,d). The saturation magnetization of the γ-Fe2O3 colloid (4.4 mg/mL was 0.307 A·m2·kg−1 at 260 K. The critical parameter for the

• stretching vibrations of the amine groups and polysaccharides, respectively. The similarity between the magnetic hysteresis of neat and heparin-modified nanoparticles indicated that the polymer-coated nanoparticles retained the same superparamagnetic behavior. However, a small decrease in the saturation

• temperature and magnetic field showed a typical superparamagnetic behavior of the γ-Fe2O3 nanoparticles with a saturation magnetization of 0.307 A∙m2·kg−1 at 260 K. The similarity of the magnetic hysteresis and ZF-C/F-C curves of the neat and modified nanoparticles indicated that the coatings did not affect

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

• 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

Tungsten disulfide-based nanocomposites for photothermal therapy

• Tzuriel Levin,
• Hagit Sade,
• Rina Ben-Shabbat Binyamini,
• Maayan Pour,
• Iftach Nachman and
• Jean-Paul Lellouche

Beilstein J. Nanotechnol. 2019, 10, 811–822, doi:10.3762/bjnano.10.81

• magnetic field until it approaches saturation, and there is no hysteresis loop. Superparamagnetism is typical for iron-oxide nanoparticles [67]. The nanocomposite WS2-NT-CM (blue curve) maintains superparamagnetism, with a saturation value of about ±13 emu/g, which is a sixth of the saturation value for

An efficient electrode material for high performance solid-state hybrid supercapacitors based on a Cu/CuO/porous carbon nanofiber/TiO₂ hybrid composite

• Mamta Sham Lal,
• Thirugnanam Lavanya and
• Sundara Ramaprabhu

Beilstein J. Nanotechnol. 2019, 10, 781–793, doi:10.3762/bjnano.10.78

• good access of electrolyte to the electrode surface. Figure 7a shows the N2 adsorption–desorption isotherm with hysteresis loop from 0.3 to 1 P/P0 for the Cu/CuO/PCNF/TiO2 composite. The BET specific surface area of the Cu/CuO/PCNF/TiO2 composite was found to be 71.879 m2 g−1. Pores with a mean

On the transformation of “zincone”-like into porous ZnO thin films from sub-saturated plasma enhanced atomic layer deposition

• Alberto Perrotta,
• Julian Pilz,
• Stefan Pachmajer,
• Antonella Milella and
• Anna Maria Coclite

Beilstein J. Nanotechnol. 2019, 10, 746–759, doi:10.3762/bjnano.10.74

• a type-II isotherm is associated with nonporous materials. Mesoporous materials are instead characterized by a type-IV isotherm, in which a hysteresis arises in the desorption step, due to the condensation of water in the pores. The adsorptive uptake was expressed as adsorptive volume obtained from

• stated, burning of the organic functionalities reduces the amount of carbon in the layers and, in turn, the swelling upon water exposure. In the literature, mesoporous materials showed hysteresis in the adsorption and desorption branches [78]. For the zincone-like layers, despite the increase in the

• refractive index at 60% and 80% relatice humidity, no or limited hysteresis was witnessed. Under these conditions, the pores are generally on the edge between microporosity and mesoporosity, that is, of the order of 1–3 nm in pore diameter. The amount of porosity measured in the layers is reported in Figure

Polymorphic self-assembly of pyrazine-based tectons at the solution–solid interface

• Achintya Jana,
• Puneet Mishra and
• Neeladri Das

Beilstein J. Nanotechnol. 2019, 10, 494–499, doi:10.3762/bjnano.10.50

• lattice parameters as well as the number, type, and orientation of molecules within a unit cell. In general, the STM experiments conducted under ambient conditions are prone to thermal drift and suffer from piezo creep and hysteresis. To overcome this limitation, the acquired STM images were corrected by

Wearable, stable, highly sensitive hydrogel–graphene strain sensors

• Jian Lv,
• Chuncai Kong,
• Chao Yang,
• Lu Yin,
• Itthipon Jeerapan,
• Fangzhao Pu,
• Xiaojing Zhang,
• Sen Yang and
• Zhimao Yang

Beilstein J. Nanotechnol. 2019, 10, 475–480, doi:10.3762/bjnano.10.47

• -hydrogel and the electron conduction change of the graphene film under different contact conditions [15] (spacing variations and contact area under stretching). The ionic conductivity is responsible for the electrical conductivity of the bare WG-hydrogel. The hysteresis curve for graphene/WG-hydrogel

• strain sensor is illustrated in Supporting Information File 1, Figure S3. The stretching and releasing curve is almost symmetric, indicating that hysteresis is not obvious. Supporting Information File 1, Figure S4 shows optical images of the graphene/hydrogel composite before and after 10 times 25

• showing the real life application of the strain sensor to sense the movement of the proximal interphalangeal joint (c) and the metacarpophalangeal joint (d). Supporting Information Yield strain stress curve of the hydrogels; Cross-section SEM image of the graphene/hydrogel composite; Hysteresis curve for

Nanocomposite–parylene C thin films with high dielectric constant and low losses for future organic electronic devices

• Marwa Mokni,
• Gianluigi Maggioni,
• Abdelkader Kahouli,
• Sara M. Carturan,
• Walter Raniero and
• Alain Sylvestre

Beilstein J. Nanotechnol. 2019, 10, 428–441, doi:10.3762/bjnano.10.42

• of samples B and C, the dose of which is higher than expected, is not completely clear, but it is thought to lie mainly in the very peculiar nature of the parylene deposition process, which is controlled by setting the pressure inside the chamber. This control method gives rise to hysteresis loops in

Improving control of carbide-derived carbon microstructure by immobilization of a transition-metal catalyst within the shell of carbide/carbon core–shell structures

• Teguh Ariyanto,
• Jan Glaesel,
• Andreas Kern,
• Gui-Rong Zhang and
• Bastian J. M. Etzold

Beilstein J. Nanotechnol. 2019, 10, 419–427, doi:10.3762/bjnano.10.41

• type I and type II with a pronounced H3 hysteresis loop. It suggests that a larger pore exists in CDC-Ni5, which is likely induced by the graphitizing effect of the nickel catalyst, as described in [18][31]. Increasing the nickel loading from 5 to 30 mg·g−1 carbide, leads to similar isotherm shapes but

One-step nonhydrolytic sol–gel synthesis of mesoporous TiO₂ phosphonate hybrid materials

• Yanhui Wang,
• P. Hubert Mutin and
• Johan G. Alauzun

Beilstein J. Nanotechnol. 2019, 10, 356–362, doi:10.3762/bjnano.10.35

• isotherms of TiO2 and of the hybrid samples are mainly of type IVa, characteristic of mesoporous adsorbents, with an H2 hysteresis loop indicating complex pore structures [38]. The TiP0.02 and TiP0.05 isotherms also showed Type II features (lack of plateau at high relative pressure) suggesting the presence

Heating ability of magnetic nanoparticles with cubic and combined anisotropy

• Nikolai A. Usov,
• Mikhail S. Nesmeyanov,
• Elizaveta M. Gubanova and
• Natalia B. Epshtein

Beilstein J. Nanotechnol. 2019, 10, 305–314, doi:10.3762/bjnano.10.29

• , Moscow, Russia National Research Nuclear University “MEPhI”, 115409, Moscow, Russia 10.3762/bjnano.10.29 Abstract The low frequency hysteresis loops and specific absorption rate (SAR) of assemblies of magnetite nanoparticles with cubic anisotropy are calculated in the diameter range of D = 20–60 nm

• appreciable contribution to the total particle energy. As a result, the nanoparticles having shape perturbation possess combined magnetic anisotropy [23]. In this paper the low frequency hysteresis loops and the SAR of magnetite nanoparticles with cubic and combined magnetic anisotropy have been calculated

• /2. The nanoparticle elongations are supposed to be small, ξmax ≤ 1.2, so that various spheroids are close to a sphere. The calculations show that in the limit Np >> 1 the averaged hysteresis loop of cluster assembly has a rather small dispersion being averaged over 30–40 independent realizations of

Nanoporous water oxidation electrodes with a low loading of laser-deposited Ru/C exhibit enhanced corrosion stability

• Sandra Haschke,
• Dmitrii Pankin,
• Vladimir Mikhailovskii,
• Maïssa K. S. Barr,
• Adriana Both-Engel,
• Alina Manshina and
• Julien Bachmann

Beilstein J. Nanotechnol. 2019, 10, 157–167, doi:10.3762/bjnano.10.15

• ruthenium catalyst as prepared is present as oxidized Ru(IV). This observation is consistent with the XPS analyses presented above. The consecutive cycles yield a rather constant hysteresis area, which indicates a low loss of material in electrochemical conditions. This relative stability of our nanoporous

• H2O to O2 visible at >0.9 V within 10 cycles is much more significant with the planar surface than with its porous counterpart. The area of the voltammetric hysteresis decreases concomitantly. These observations point to the rapid loss of noble metal catalyst from planar Ru/C surfaces. The contrasting

pH-mediated control over the mesostructure of ordered mesoporous materials templated by polyion complex micelles

• Emilie Molina,
• Mélody Mathonnat,
• Jason Richard,
• Patrick Lacroix-Desmazes,
• Martin In,
• Philippe Dieudonné,
• Thomas Cacciaguerra,
• Corine Gérardin and
• Nathalie Marcotte

Beilstein J. Nanotechnol. 2019, 10, 144–156, doi:10.3762/bjnano.10.14

• with H1-like hysteresis loop (IUPAC classification [34]) showing capillary condensation at a relative pressure p/p0 ranging from 0.42 to 0.70. This indicates that the structural mesoporosity presents a cylindrical pore geometry with a high degree of pore size uniformity. This is confirmed by the narrow

• the hexagonal materials becomes less pronounced, and the hysteresis loop extends on a wider partial pressure range, in agreement with the presence of lamellar domains coexisting with wormhole pore morphologies. The increase of pH from 5.5 to 6.9 resulted in a size pore increase with broadening PSD

• image of Figure 4a. The N2 sorption isotherm (Figure 4b) exhibited the classical H3-like hysteresis loop expected for such a mesostructure, with a mesoporous volume of 0.17 cm3·g−1. A pore thickness of 3 nm was calculated using the Broekhof and De Boer method from the relative pressure at which complete

New micro/mesoporous nanocomposite material from low-cost sources for the efficient removal of aromatic and pathogenic pollutants from water

• Emmanuel I. Unuabonah,
• Robert Nöske,
• Jens Weber,
• Christina Günter and
• Andreas Taubert

Beilstein J. Nanotechnol. 2019, 10, 119–131, doi:10.3762/bjnano.10.11

• interstitial voids among the particles. A very modest hysteresis is observed, which closes at approximately p/p0 = 0.45. This result is indicative of a few mesopores with restricted access within the material, which are emptied by cavitation [27]. Furthermore, analysis of 2Z-HYCA vs the synthesis temperature

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

• for the increase of the D band in the Raman spectra are related to magnetic changes in HOPG samples [37], magnetization measurements were conducted in order to attempt a more complete characterization of our samples. Hysteresis loops of pristine HOPG and the irradiated samples were measured at 4 K

• work, while the dashed, dashed-dotted and dotted lines are taken from Eckmann and co-workers [35]. The symbols +, * and # refer to sp3-hybridized bonds, vacancies, and boundary defects, respectively. a) Hysteresis loops of pristine HOPG and irradiated samples with low (LD) and high (HD) H+ doses, in

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

• properties are presented in this section. We measure zero-field cooling and field cooling (ZFC/FC) at an applied field of µ0H = 5 mT and hysteresis loops in the field range µ0H = ±9 T in the temperature interval 5–350 K for MNP-15 and MNP-25 and 5–390 K for samples MNP-6 and MNP-44. Figure 4A presents the

• the TEM diameter of 44 nm. In contrast, the diameter of Fe3O4 in sample MNP-25, as determined by TEM and XRD, is the same within the error bar. Figure 4B shows the magnetic hysteresis loops at T = 5 K and T = 300 K. All samples have an open hysteresis at T = 5 K while at ambient temperature only the

• the higher blocking temperature. Thus, all NPs in MNP-44 contribute to the temperature rise via Néel losses. Hysteresis losses prevail and stabilize the SLP values for MNP-25 and MNP-44 at 3.6 mg·mL−1 Fe concentration (Figure 6C). As a reference, the heating rate and corresponding SLP are also

Exploring the photoleakage current and photoinduced negative bias instability in amorphous InGaZnO thin-film transistors with various active layer thicknesses

• Dapeng Wang and
• Mamoru Furuta

Beilstein J. Nanotechnol. 2018, 9, 2573–2580, doi:10.3762/bjnano.9.239

• visible light irradiation exceeded ≈2.7 eV. Furthermore, the influence of the TIGZO on NBIS-induced instability in a-IGZO TFTs was explored by the combination of current–voltage measurements in double-sweeping VGS mode and capacitance–voltage measurements. The NBIS-induced hysteresis was quantitatively

• to device instability and restricts the development of oxide TFTs for commercial products. In our previous study, a double-sweeping VGS mode was proposed to investigate the origin of NBIS-induced hysteresis of a-IGZO TFTs [17]. A promising method to suppress NBIS degradation was also considered by

• explored by combining the current–voltage (I–V) measurements in double-sweeping VGS mode and capacitance–voltage (C–V) measurements. The NBIS-induced hysteresis was quantitatively analyzed using a positive gate pulse mode. The I–V and C–V results revealed that the trapped holes at the etch-stopper/IGZO

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

• , the Rxy(H) should reproduce the field dependence of the magnetization. As shown in Figure 3a, Rs·M(H) (the Hall resistivity after subtraction of the linear contribution) demonstrates hysteresis behavior (see inset) with Hc ≈ 140 Oe and a saturation field value of Hsat ≈ 3.8 kOe. This is in a good

• hysteresis at room temperature perfectly fits the idea of a dominant contribution of MnSb inclusions with Tc > 400 K interacting with holes. This is confirmed by the appearance of a substantial anomalous Hall effect even at room temperature that signifies the presence of spin-polarized charge carriers. The

Hydrothermal-derived carbon as a stabilizing matrix for improved cycling performance of silicon-based anodes for lithium-ion full cells

• Mirco Ruttert,
• Florian Holtstiege,
• Jessica Hüsker,
• Markus Börner,
• Martin Winter and
• Tobias Placke

Beilstein J. Nanotechnol. 2018, 9, 2381–2395, doi:10.3762/bjnano.9.223

• . For example, they maintain a high specific capacity (372 mAh g−1) compared to cathode materials, high electrochemical stability in suitable electrolytes, a low operation potential (0.2 V vs Li/Li+), low voltage hysteresis, low cost, and are environmentally friendly [7][8]. Nonetheless, alternative

• , the VE is lower than before and stabilizes at ≈94% in both cases. The decrease compared to the formation cycles is most likely due to stronger polarization effects of the electrodes at higher currents [8][70]. A high VE indicates a small voltage hysteresis between charge and discharge of the cell

Pinning of a ferroelectric Bloch wall at a paraelectric layer

• Vilgelmina Stepkova and
• Jiří Hlinka

Beilstein J. Nanotechnol. 2018, 9, 2356–2360, doi:10.3762/bjnano.9.220

• layer could be easily switched with a 0.5 kV/mm electric field, as is apparent from the quasistatic hysteresis loop shown in Figure 8 (see below). In fact, the thickness of the SrTiO3 layer can be tuned in a way that the wall passing through there is effectively in the state just below the phase

• the walls in the simulation box, but there were no real constrains introduced there, only the natural limitations resulting from the standard protocol of simulated annealing procedure, governed by the time-dependent Ginzburg–Landau equation. The hysteresis loop shown in Figure 8 has been calculated

• and (b) with the thickness of the SrTiO3 layer. Landau part of the domain wall energy density as a function of the position of the ferroelectric domain wall, estimated by sliding a rigid polarization profile across the potential relief of the superlattice described in the text. Calculated hysteresis