The effect of magneto-crystalline anisotropy on the properties of hard and soft magnetic ferrite nanoparticles

• Hajar Jalili,
• Bagher Aslibeiki,
• Ali Ghotbi Varzaneh and
• Volodymyr A. Chernenko

Beilstein J. Nanotechnol. 2019, 10, 1348–1359, doi:10.3762/bjnano.10.133

• to destroy cancer cells through the elevated temperatures [16][17]. The heating efficiency of the NPs as heat sources under ac magnetic fields is often denominated as specific absorption rate (SAR), which is directly related to the area of the magnetic hysteresis loop of the nanoparticles by the

• following formula [18][19]: where f is the field frequency, c is the weight concentration of the material and A is the area of the hysteresis loop. Size and shape of the particles, saturation magnetization and magnetic anisotropy, as well as field amplitude and frequency strongly affect the hyperthermia

• reported for NixCo1−xFe2O4 by Caetano and co-workers [15]. They showed that the heat generation increases with Ni content because of an increase of the minor hysteresis loop area. Our results can be related to the magnetic anisotropy of the NPs. When the coercivity of the NPs is larger than the field

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

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

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

• ) Size-distribution histogram of γ-Fe2O3 nanoparticles. (a) ATR-FTIR spectra of (i) γ-Fe2O3, (ii) γ-Fe2O3@Hep, (iii) γ-Fe2O3@Hep-CS-G, (iv) γ-Fe2O3@Hep-CS-H, and (v) γ-Fe2O3@Hep-CS-P nanoparticles. (b) TGA of (i) γ-Fe2O3, (ii) γ-Fe2O3@Hep, and (iii) γ-Fe2O3@Hep-CS-G. (c) Magnetic hysteresis loop of 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

• 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

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

• /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

• low frequency hysteresis loop of the assembly changes considerably as a function of nanoparticle diameter at fixed values of other parameters. For the case of nanoparticles with tsh = 20 nm, the area of the hysteresis loop is maximal for nanoparticles with diameter D = 45 nm. Therefore, for assemblies

• among the closest nanoparticles of the cluster. As a result, the area of the hysteresis loop increases as a function of tsh. One can see in Figure 2b that the area of the hysteresis loop is the largest one for the assembly of noninteracting nanoparticles when formally tsh → ∞. On the other hand, the

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

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

• were performed with the magnetic field oriented parallel to the sample plane (solid symbols) and perpendicularly to it (open symbols). The inset shows the hysteresis loop at low fields. (b) Temperature dependence of the remanent magnetization. Open circles are SQUID data for sample GM3, red squares are

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

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

• -dependent micromagnetic simulations. Such a fast movement of the domain walls cannot be sensed in a static hysteresis loop, which will change “instantaneously” the direction of the magnetization at the “switching field” similar to the case of a S–W-like coherent rotation. Moreover, there is an equivalent

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

• . The asymmetric hysteresis loop and training effect observed at low temperature is related to the presence of a metastable AF domain state. We show that both the static and dynamic magnetic properties of trilayer films can be adjusted over a wide range by changing the thickness of the IrMn spacer layer

• AF-induced interfacial damping parameter is also calculated. At low temperatures, the asymmetric hysteresis loop and training effect indicates the presence of a dynamic AF spin structure instead of a static structure. Experimental FM/AF/FM trilayers of Co20Fe60B20 (10 nm)/Ir19Mn81 (tIrMn)/Co20Fe60B20

• (Figure 9). We indeed found a strong training effect in the second loop, where there is large decrease in the values of coercivity and exchange bias along with a symmetrically rounded reversal at both branches of the hysteresis loop. This training results from the effect, where the initial field cooling

Controllable one-pot synthesis of uniform colloidal TiO₂ particles in a mixed solvent solution for photocatalysis

• Jong Tae Moon,
• Seung Ki Lee and
• Ji Bong Joo

Beilstein J. Nanotechnol. 2018, 9, 1715–1727, doi:10.3762/bjnano.9.163

• adsorption/desorption isotherm and corresponding Barrett–Joyner–Halenda (BJH) pore size distributions of the TiO2 samples. The TiO2 sample calcined at 400 °C (TiO2-400) displayed a typical type IV isotherm with a well-developed hysteresis loop that indicated mesoscale porosity (Figure 5a). The TiO2 sample

Nanoscale electrochemical response of lithium-ion cathodes: a combined study using C-AFM and SIMS

• Jonathan Op de Beeck,
• Nouha Labyedh,
• Alfonso Sepúlveda,
• Valentina Spampinato,
• Alexis Franquet,
• Thierry Conard,
• Philippe M. Vereecken,
• Wilfried Vandervorst and
• Umberto Celano

Beilstein J. Nanotechnol. 2018, 9, 1623–1628, doi:10.3762/bjnano.9.154

• electrical conductivity as highly lithiated regions show enhanced electrical conductivity. Appearance of the ionic hysteresis and influence of Li depletion during preconditioning. (a) The hysteresis loop visible in the I–V curves is indicating the local change in resistance under the tip induced by the Li

• modulation. The inset shows a schematic of the migration of Li ions towards the AFM tip. The measurements were performed on RF-sputtered LMO under high vacuum at a sweep rate of 0.2 Hz. (b) An enhanced hysteresis loop opening, i.e., electrochemical response, can be observed due to a preconditioning dc scan

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

• theoretically driven route for a feasible fabrication of metal nanostructures has been demonstrated with this work. Concerning magnetic samples and their properties, a hysteresis loop of cobalt nanoholes is presented in Figure 5d as obtained by magneto-optic Kerr effect (MOKE) measurements – a ferromagnetic

Magnetic characterization of cobalt nanowires and square nanorings fabricated by focused electron beam induced deposition

• Federico Venturi,
• Gian Carlo Gazzadi,
• Amir H. Tavabi,
• Alberto Rota,
• Rafal E. Dunin-Borkowski and
• Stefano Frabboni

Beilstein J. Nanotechnol. 2018, 9, 1040–1049, doi:10.3762/bjnano.9.97

• of a square hysteresis loop with a coercive field of approximately 10 mT. L-TEM images of square nanorings revealed a horseshoe magnetic state, which could be changed to an opposite horseshoe state by reversing the magnetic field applied in situ. By increasing the external magnetic field and

• leftwards along the NW in (c) and (d) as the specimen tilt angle is increased, thus increasing the leftward-oriented component of the lens field in the sample plane (Beff). Blue and red arrows mark the opposite magnetic domains M1 and M2, respectively. (e) Hysteresis loop of the NW measured as a function of

Facile synthesis of a ZnO–BiOI p–n nano-heterojunction with excellent visible-light photocatalytic activity

• Mengyuan Zhang,
• Jiaqian Qin,
• Pengfei Yu,
• Bing Zhang,
• Mingzhen Ma,
• Xinyu Zhang and
• Riping Liu

Beilstein J. Nanotechnol. 2018, 9, 789–800, doi:10.3762/bjnano.9.72

• heterostructured nanocomposites of ZnO and BiOI. The structural characteristics of the as-prepared ZnO/BiOI composites were revealed by nitrogen adsorption–desorption isotherms shown in Figure S3, Supporting Information File 1. The isotherm of sample B-4, with a unique hysteresis loop and a classical two capillary

Synthesis and characterization of two new TiO₂-containing benzothiazole-based imine composites for organic device applications

• Anna Różycka,
• Agnieszka Iwan,
• Krzysztof Artur Bogdanowicz,
• Michal Filapek,
• Natalia Górska,
• Damian Pociecha,
• Marek Malinowski,
• Patryk Fryń,
• Agnieszka Hreniak,
• Jakub Rysz,
• Paweł Dąbczyński and
• Monika Marzec

Beilstein J. Nanotechnol. 2018, 9, 721–739, doi:10.3762/bjnano.9.67

• characteristic for mesoporous materials. As can be seen in Figure 1a, this isotherm possesses a characteristic feature of a hysteresis loop, which is the consequence of adsorbate condensation in TiO2 pores. The limiting adsorption at the high pressure close to 1.0 p/p0 results in a plateau of the isotherm

• , indicating the complete pore filling (according to the type IV isotherm model). However, this effect was not observed in the case of TiO2 since the material isotherm is a combination of both II and IV types. The shape of the hysteresis loop is correlated with pore size distribution and pore geometry

• . According to the IUPAC, four types of hysteresis loop shapes can be distinguished [44]. Based on the shape analysis of the TiO2 hysteresis loop (Figure 1a) one can assign it to the H3 shape, which means that the material structure consists of slit-shape mesopores. The result of this geometry can be

Photocatalytic and adsorption properties of TiO₂-pillared montmorillonite obtained by hydrothermally activated intercalation of titanium polyhydroxo complexes

• Mikhail F. Butman,
• Nikolay L. Ovchinnikov,
• Nikita S. Karasev,
• Nataliya E. Kochkina,
• Alexander V. Agafonov and
• Alexandr V. Vinogradov

Beilstein J. Nanotechnol. 2018, 9, 364–378, doi:10.3762/bjnano.9.36

• samples are shown in Figure 6a. All the isotherms are characterized by the presence of capillary condensation hysteresis loops and belong to type IV according to IUPAC classification [39], which is typical for materials with mesoporous structure. Furthermore, the shape of the hysteresis loop for these

Review: Electrostatically actuated nanobeam-based nanoelectromechanical switches – materials solutions and operational conditions

• Liga Jasulaneca,
• Jelena Kosmaca,
• Raimonds Meija,
• Jana Andzane and
• Donats Erts

Beilstein J. Nanotechnol. 2018, 9, 271–300, doi:10.3762/bjnano.9.29

• significant contribution of vdW forces [69], jump-off occurs at lower voltages in comparison to jump-in, and typical hysteresis loops in I(V) curves of NEM switches are observed [8][10][15]. A hysteresis loop is illustrated in Figure 2b showing experimentally obtained results [15] in comparison with the

Bombyx mori silk/titania/gold hybrid materials for photocatalytic water splitting: combining renewable raw materials with clean fuels

• Stefanie Krüger,
• Michael Schwarze,
• Otto Baumann,
• Christina Günter,
• Michael Bruns,
• Christian Kübel,
• Dorothée Vinga Szabó,
• Rafael Meinusch,
• Verónica de Zea Bermudez and
• Andreas Taubert

Beilstein J. Nanotechnol. 2018, 9, 187–204, doi:10.3762/bjnano.9.21

• , the fraction of TiO2 in TPS is ca. 8% higher than in TS. Figure 7 shows nitrogen sorption data obtained from the Au-free and Au-modified samples. All samples show a type IV(a) isotherm with a type H2(a) hysteresis loop; the hysteresis loop is typical for materials with pore diameters wider than 4 nm

Beyond Moore’s technologies: operation principles of a superconductor alternative

• Igor I. Soloviev,
• Nikolay V. Klenov,
• Sergey V. Bakurskiy,
• Mikhail Yu. Kupriyanov,
• Alexander L. Gudkov and
• Anatoli S. Sidorenko

Beilstein J. Nanotechnol. 2017, 8, 2689–2710, doi:10.3762/bjnano.8.269