Unveiling the nature of atomic defects in graphene on a metal surface

• Karl Rothe,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2024, 15, 416–425, doi:10.3762/bjnano.15.37

• , the Δf traces for the tetravacancy exhibit a hysteresis loop in tip approach and retraction cycles. The width of the loop, defined as δ = Δzp − Δza with Δza and Δzp denoting the tip excursions where Δf↓ and Δf↑ intersect (Figure 5c), varies across the defect. Large values of δ are mostly observed at

• retraction (I↑) current data, albeit with a smaller width of the hysteresis loop. The onset of deviations of I↓ from a uniform exponential increase, marked Δzc in the inset to Figure 5f, signals the collapse of the tunneling barrier and the formation of a chemical bond between the tip and the surface [32][36

• reached. To this end, the tip has to be displaced further by Δz > Δzc to reach the energy minimum. The hysteresis loop in Δf and I data can, therefore, be rationalized in terms of a Au–C bond that is formed upon approaching the tip to the defect up to the point of maximum attraction at Δzc ≈ Δz0. This

Modulated critical currents of spin-transfer torque-induced resistance changes in NiCu/Cu multilayered nanowires

• Mengqi Fu,
• Roman Hartmann,
• Julian Braun,
• Sergej Andreev,
• Torsten Pietsch and
• Elke Scheer

Beilstein J. Nanotechnol. 2024, 15, 360–366, doi:10.3762/bjnano.15.32

• at a positive critical current Ic+ of 1.5 mA in the upsweep of I (initiating from a large negative current) and an abrupt jump at a negative critical current Ic− of around −1.2 mA in the downsweep of I (starting from a large positive current), thereby forming a hysteresis loop. The hysteresis loop

• number of contacted nanowires can be estimated to be around six in the present case; for detailed calculations see Supporting Information File 1. The maximal dV/dI is achieved at µ0H ≈ −21 mT/21 mT in the downsweep/upsweep of the magnetic field, respectively. The gradual changes in the dV/dI hysteresis

• loop may be attributed to multidomain structures in the long NiCu segment and wire-to-wire variations of the interaction between the segments of the nanowires. Several jumps and drops are observed, which are mainly mirror-symmetrically distributed in the upsweep and downsweep curves. Since dV/dI

Vinorelbine-loaded multifunctional magnetic nanoparticles as anticancer drug delivery systems: synthesis, characterization, and in vitro release study

• Zeynep Özcan and
• Afife Binnaz Hazar Yoruç

Beilstein J. Nanotechnol. 2024, 15, 256–269, doi:10.3762/bjnano.15.24

• × magnification. (d) Particle diameter distribution of Fe3O4 NPs. (a) X-ray diffraction patterns of Fe3O4 NPs. (b) FTIR spectra of Fe3O4 NPs. (c) Hysteresis loop for Fe3O4 NPs. FESEM images of (a) PDA/Fe3O4 NPs (1:1), (b) PDA/Fe3O4 NPs (2:1), and (c) PDA/Fe3O4 NPs (4:1), all 250,000× magnification. (d) FTIR

Ferromagnetic resonance spectra of linear magnetosome chains

• Elizaveta M. Gubanova and
• Nikolai A. Usov

Beilstein J. Nanotechnol. 2024, 15, 157–167, doi:10.3762/bjnano.15.15

• is well known [14][15][33][34][35] that the power absorbed by the assembly per unit time and per unit volume is proportional to the area of the assembly hysteresis loop where m is the reduced magnetic moment of the assembly. To numerically calculate the power absorbed by an assembly of

Upscaling the urea method synthesis of CoAl layered double hydroxides

• Camilo Jaramillo-Hernández,
• Víctor Oestreicher,
• Martín Mizrahi and
• Gonzalo Abellán

Beilstein J. Nanotechnol. 2023, 14, 927–938, doi:10.3762/bjnano.14.76

• hysteresis loop [71][72][73][74][75][76] and a low specific surface area (<50 m2/g) as previously reported [46]. Additional data, such as pore contributions (micro-, meso- and macropores) and other textural parameters, are compiled in Figure S16 and Table S8 (Supporting Information File 1). To conclude

Specific absorption rate of randomly oriented magnetic nanoparticles in a static magnetic field

• Ruslan A. Rytov and
• Nikolai A. Usov

Beilstein J. Nanotechnol. 2023, 14, 485–493, doi:10.3762/bjnano.14.39

• of the field-free point is obtained for assemblies with different nanoparticle size distributions. The results obtained seem to be helpful for the development of a promising joint application of magnetic nanoparticle imaging and magnetic hyperthermia. Keywords: dynamic hysteresis loop; magnetic

• magnetic nanoparticles in a liquid, an increase of the dc magnetic field leads to a decrease in the area of the hysteresis loop for both parallel and perpendicular configurations of external magnetic fields. Analytical and numerical calculations of the dynamics of the nanoparticle magnetization in an ac

• combined action of ac and dc magnetic fields is studied using a numerical simulation based on the solution of the stochastic Landau–Lifshitz equation [17][20][22][23][26]. The SAR of a randomly oriented assembly is calculated in terms of the area of the dynamic hysteresis loop according to the well-known

A novel approach to pulsed laser deposition of platinum catalyst on carbon particles for use in polymer electrolyte membrane fuel cells

• Bogusław Budner,
• Wojciech Tokarz,
• Sławomir Dyjak,
• Andrzej Czerwiński,
• Bartosz Bartosewicz and
• Bartłomiej Jankiewicz

Beilstein J. Nanotechnol. 2023, 14, 190–204, doi:10.3762/bjnano.14.19

• mesoporosity, i.e., a wider hysteresis loop and a higher isotherm with p/p0 values approaching 1. Both isotherms (i.e., of XC-72R and C-11) can be classified as type II (according to IUPAC classification [39]) but with H3-type hysteresis loops. A sharp increase of N2 adsorption capacity at p/p0 values

Investigation of a memory effect in a Au/(Ti–Cu)Ox-gradient thin film/TiAlV structure

• Damian Wojcieszak,
• Jarosław Domaradzki,
• Michał Mazur,
• Tomasz Kotwica and
• Danuta Kaczmarek

Beilstein J. Nanotechnol. 2022, 13, 265–273, doi:10.3762/bjnano.13.21

• [2][21][39]. Some examples of resistive switching behavior were also found in structures based on nanowires [40] or nanotubes [25][40], where the resistive switching device is characterized by the presence of a pinched or nonpinched hysteresis loop in the I–V characteristics in the DC plane. Our

Heating ability of elongated magnetic nanoparticles

• Elizaveta M. Gubanova,
• Nikolai A. Usov and
• Vladimir A. Oleinikov

Beilstein J. Nanotechnol. 2021, 12, 1404–1412, doi:10.3762/bjnano.12.104

• is well known that the SAR of an assembly of magnetic nanoparticles is proportional to the area of the low-frequency hysteresis loop of the assembly. It can be calculated [18][20] by the formula SAR = 10−7MsfA/ρ (W/g), where A is the hysteresis loop area in the variables (M/Ms, H), and ρ is the

• can see that for particles with a large aspect ratio, a/b = 3.0, the area of the low-frequency hysteresis loop changes extremely rapidly with a change of the transverse diameter in the range of 8–10 nm. The explanation of the observed behavior of the SAR of non-interacting assembly of elongated

• hysteresis loop area of the oriented assembly is significantly larger than that of the non-oriented one. Accordingly, as Figure 3b shows, the SAR of the oriented assembly at the maximum is approximately two times higher than that of the non-oriented assembly. Nevertheless, for both types of assemblies the

Free and partially encapsulated manganese ferrite nanoparticles in multiwall carbon nanotubes

• Saja Al-Khabouri,
• Salim Al-Harthi,
• Toru Maekawa,
• Mohamed E. Elzain,
• Ashraf Al-Hinai,
• Ahmed D. Al-Rawas,
• Abbsher M. Gismelseed,
• Ali A. Yousif and
• Myo Tay Zar Myint

Beilstein J. Nanotechnol. 2020, 11, 1891–1904, doi:10.3762/bjnano.11.170

• particles, in addition to the sextets, is detected (Figure 1f). Hysteresis loops at 77 and 4 K display an increase in magnetization, compared to the hysteresis loop at 300 K, as a result of the decrease in thermal energy as the temperature decreases [20]. As the temperature decreases, the coercivity

Unravelling the interfacial interaction in mesoporous SiO₂@nickel phyllosilicate/TiO₂ core–shell nanostructures for photocatalytic activity

• Bridget K. Mutuma,
• Xiluva Mathebula,
• Isaac Nongwe,
• Bonakele P. Mtolo,
• Boitumelo J. Matsoso,
• Rudolph Erasmus,
• Zikhona Tetana and
• Neil J. Coville

Beilstein J. Nanotechnol. 2020, 11, 1834–1846, doi:10.3762/bjnano.11.165

• type IV, demonstrating the presence of a mesoporous structure associated with capillary condensation [45][46]. The mSiO2 spheres exhibited a type-H2 hysteresis loop confined at 0.35 < P/P0 < 0.6, indicating the presence of randomly interconnected pore systems [47]. In contrast, the mSiO2@NiPS core

• –shell nanostructures showed a type-H1 hysteresis loop, implying the existence of agglomerates with cylindrical pores [45][48]. Similar to the mSiO2@NiPS composite, the mSiO2@NiPS/TiO2 exhibited a type-IV isotherm with a type-H1 hysteresis loop, illustrating the presence of mesopores with randomly

On the frequency dependence of viscoelastic material characterization with intermittent-contact dynamic atomic force microscopy: avoiding mischaracterization across large frequency ranges

• Enrique A. López-Guerra and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2020, 11, 1409–1418, doi:10.3762/bjnano.11.125

• approximately doubles between 70 and 350 kHz, while a calculation with Equation 4 shows that its loss modulus increases by a factor of approximately 4.7 in the same frequency range. Additionally, material 1 now exhibits an obvious hysteresis loop, whereby the surface relaxes approximately 0.8 nm, leading to tip

• –sample dissipation and a different phase response between the two materials [36][37] (at 350 kHz material 2 shows an imperceptible hysteresis loop and similar indentation as for 70 kHz). The increase in hysteresis is also consistent with the increase in the loss modulus, evident in Figure 2b. A

• obvious hysteresis loop, which the softer cantilever was not able to probe. Finally, we see that the oscillation amplitude as a function of the cantilever position is larger for the larger force constant, and also decreases less rapidly, confirming that the sample is less capable of perturbing the

Structure and electrochemical performance of electrospun-ordered porous carbon/graphene composite nanofibers

• Yi Wang,
• Yanhua Song,
• Chengwei Ye and
• Lan Xu

Beilstein J. Nanotechnol. 2020, 11, 1280–1290, doi:10.3762/bjnano.11.112

• their corresponding pore-size distribution (PSD) curves were obtained by using Barrett–Joyner–Halenda (BJH) analysis, as illustrated in Figure 4. The adsorption isotherms of DCGCNFs, OCGCNFs, and OPCGCNFs in Figure 4a showed a typical type IV behavior. There was a visible hysteresis loop between the

• . This is due to the fact that large mesoporous holes are more suitable for rapid ion diffusion at a high-load current density. This way, the specific surface area generated by these pores is effectively utilized [39]. At relatively high pressure values (P/P0 > 0.5), there was an evident hysteresis loop

Proximity effect in [Nb(1.5 nm)/Fe(x)]₁₀/Nb(50 nm) superconductor/ferromagnet heterostructures

• Yury Khaydukov,
• Sabine Pütter,
• Laura Guasco,
• Roman Morari,
• Gideok Kim,
• Thomas Keller,
• Anatolie Sidorenko and
• Bernhard Keimer

Beilstein J. Nanotechnol. 2020, 11, 1254–1263, doi:10.3762/bjnano.11.109

• and (b) sample s6. Dashed tilted lines show the direction of specular reflection. The color bars show the logarithmic intensity scale. SQUID data of the s3 sample. (a) Hysteresis loop measured at T = 300 K (red) and T = 13 K (black). (b) Temperature dependence of the magnetic moment measured at H

Observation of unexpected uniaxial magnetic anisotropy in La_2/3Sr_1/3MnO₃ films by a BaTiO₃ overlayer in an artificial multiferroic bilayer

• John E. Ordóñez,
• Lorena Marín,
• Luis A. Rodríguez,
• Pedro A. Algarabel,
• José A. Pardo,
• Roger Guzmán,
• Luis Morellón,
• César Magén,
• Etienne Snoeck,
• María E. Gómez and
• Manuel R. Ibarra

Beilstein J. Nanotechnol. 2020, 11, 651–661, doi:10.3762/bjnano.11.51

• samples grown on LSAT (Figure 3d) and LAO (Figure 3f) we do not detect appreciable changes in the shape of the hysteresis loops in comparison with those for LSMO film. However, in the bilayer grown on STO (Figure 3b), the Mr for the hysteresis loop taken along the [100] (black squares) is reduced when

Synthesis of amorphous and graphitized porous nitrogen-doped carbon spheres as oxygen reduction reaction catalysts

• Maximilian Wassner,
• Markus Eckardt,
• Andreas Reyer,
• Thomas Diemant,
• Michael S. Elsaesser,
• R. Jürgen Behm and
• Nicola Hüsing

Beilstein J. Nanotechnol. 2020, 11, 1–15, doi:10.3762/bjnano.11.1

• counterparts regarding porosity and surface areas. With the onset of graphitization, however, the g-NCS-850 and g-NCS-1000 samples develop a distinct mesoporosity (type-IV isotherms and a H2 hysteresis loop, Figure 7), concomitant with a loss of microporosity of about 66%. The formation of mesopores can be

Design and facile synthesis of defect-rich C-MoS₂/rGO nanosheets for enhanced lithium–sulfur battery performance

• Chengxiang Tian,
• Juwei Wu,
• Zheng Ma,
• Bo Li,
• Pengcheng Li,
• Xiaotao Zu and
• Xia Xiang

Beilstein J. Nanotechnol. 2019, 10, 2251–2260, doi:10.3762/bjnano.10.217

• are almost completely removed during the hydrothermal synthesis and annealing process [41]. Full nitrogen sorption isotherms of the composites were measured to obtain the specific surface area and the pore size distribution. A type-IV isotherm with a type-H3 hysteresis loop in the relative pressure

Targeted therapeutic effect against the breast cancer cell line MCF-7 with a CuFe₂O₄/silica/cisplatin nanocomposite formulation

• B. Rabindran Jermy,
• Vijaya Ravinayagam,
• Widyan A. Alamoudi,
• Dana Almohazey,
• Hatim Dafalla,
• Lina Hussain Allehaibi,
• Abdulhadi Baykal,
• Muhammet S. Toprak and
• Thirunavukkarasu Somanathan

Beilstein J. Nanotechnol. 2019, 10, 2217–2228, doi:10.3762/bjnano.10.214

• adsorption technique (Figure 2). HYPS particles show a type IV isotherm corresponding to the presence of mesopores. The silica hysteresis loop tends to be present at a higher relative pressure of P/P0 > 0.8. The HYPS texture exhibited a surface area of 170 m2/g, pore volume of 0.35 cm3/g with an intermediate

TiO₂/GO-coated functional separator to suppress polysulfide migration in lithium–sulfur batteries

• Ning Liu,
• Lu Wang,
• Taizhe Tan,
• Yan Zhao and
• Yongguang Zhang

Beilstein J. Nanotechnol. 2019, 10, 1726–1736, doi:10.3762/bjnano.10.168

• water. The remainder after the heating process was regarded as the TiO2, which accounts for 45.6 wt % of the whole. The N2 adsorption–desorption isotherm of the TiO2/GO composite is shown in Figure 2d. A distinct hysteresis loop can be identified, indicating the microporous structure of the TiO2/GO

Selective gas detection using Mn₃O₄/WO₃ composites as a sensing layer

• Yongjiao Sun,
• Zhichao Yu,
• Wenda Wang,
• Pengwei Li,
• Gang Li,
• Wendong Zhang,
• Lin Chen,
• Serge Zhuivkov and
• Jie Hu

Beilstein J. Nanotechnol. 2019, 10, 1423–1433, doi:10.3762/bjnano.10.140

• in the figure, the curves are type II isotherms with a H3 hysteresis loop, suggesting non-porous structures. The specific surface area of all samples are 14.82, 14.66, 14.23 and 13.98 m2/g, respectively, which slightly reduce with increasing Mn concentration. This result might be related to the

BiOCl/TiO₂/diatomite composites with enhanced visible-light photocatalytic activity for the degradation of rhodamine B

• Minlin Ao,
• Kun Liu,
• Xuekun Tang,
• Zishun Li,
• Qian Peng and
• Jing Huang

Beilstein J. Nanotechnol. 2019, 10, 1412–1422, doi:10.3762/bjnano.10.139

• and pore volume are shown in Table 1. Density functional theory (DFT) mode was undertaken to characterize the porosity of these samples. According to the N2 adsorption–desorption isotherms, we can see that all four samples belong to IV-type isotherms. BiOCl has an H2-type hysteresis loop, while

• diatomite, TiO2/diatomite and BTD have an H4-type hysteresis loop, indicating that all samples have a mesoporous structure. At the same time, the pore size distribution and average pore size also confirm that the samples have mesoporous structure. Figure 2b shows that the pore size distribution of BTD has a

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