Formation and development of nanometer-sized cybotactic clusters in bent-core nematic liquid crystalline compounds

• Yuri P. Panarin,
• Sithara P. Sreenilayam,
• Jagdish K. Vij,
• Anne Lehmann and
• Carsten Tschierske

Beilstein J. Nanotechnol. 2018, 9, 1288–1296, doi:10.3762/bjnano.9.121

• individual molecular modes [30][31]. Temperature dependence of the dielectric properties The dielectric spectra of BCN66 were analyzed by using the WINFIT software of Novocontrol GmbH. The dielectric data on the complex permittivity were fitted to the Havriliak–Negami (H–N) equation (Equation 1). where ε∞ is

• of the Debye type. Figure 2b shows the temperature dependence of Δεj and fj obtained from fitting the dielectric data to Equation 1 over the entire temperature range of the nematic phase and temperatures in the isotropic phase close to the isotropic–nematic transition temperature. Fitting of the

• director. The temperature dependence of the relaxation frequencies f1 and f2 obey the Arrhenius mechanism. The activation energy corresponding to the processes P1 and P2 was found to be 2.55 eV and 1.93 eV, respectively. A higher value of the activation energy for the cluster compared to that of the

Atomistic modeling of tribological properties of Pd and Al nanoparticles on a graphene surface

• Alexei Khomenko,
• Miroslav Zakharov,
• Denis Boyko and
• Bo N. J. Persson

Beilstein J. Nanotechnol. 2018, 9, 1239–1246, doi:10.3762/bjnano.9.115

• defined as the sum of atomic contact areas of all metal atoms of which the distance from their centers to the centers of carbon atoms is below than 0.5 nm (Figure 7). Figure 8 shows the temperature dependence of the friction force. The contact area almost does not change with the temperature. The maximal

• surfaces in ultrahigh vacuum [5]. The temperature dependence of the friction shown in Figure 8 can be understood as follows [20][21][22][23]: At high temperatures the friction decreases with increasing temperature due to thermal fluctuations, which help to move the particles over the energy barriers they

• tribological properties of nanoparticles depend on the material. It was noted that the substrate force that acts on the nanoparticle has a sawtooth form as a function of coordinate (and time) as is also observed in nanotribological experiments [6][13][14]. We have studied the temperature dependence of friction

P3HT:PCBM blend films phase diagram on the base of variable-temperature spectroscopic ellipsometry

• Barbara Hajduk,
• Henryk Bednarski,
• Bożena Jarząbek,
• Henryk Janeczek and
• Paweł Nitschke

Beilstein J. Nanotechnol. 2018, 9, 1108–1115, doi:10.3762/bjnano.9.102

• temperature dependence of the thickness and refractive index with cosΔ(T). In this work, we present an in-depth study of the influence of the composition of P3HT:PCBM blend films on their phase transitions using variable-temperature spectroscopic ellipsometry. We demonstrate that this non-destructive method

• the ellipsometric angle Δ at 280 nm to the temperature changes. By comparing the temperature dependence of the film thickness with the corresponding dependence of tanΨ (850 nm) and Δ (280 nm), we show that raw data of Δ at 280 nm are most convenient to determine the phase diagram of P3HT:PCBM blend

• presented in Figure 3 the corresponding temperature dependence of tanΨ taken at λ = 850 nm. Both plots, d(T) and tanΨ(T), are pairwise almost identical. This is because those materials are transparent at λ > 750 nm and their refractive indexes are weakly dependent on T in this spectral range. Regarding P3HT

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

• -prepared samples compared to the annealed samples and to the formation of a bulk-like ferromagnetic core and a shell composed of disordered moments [32][34][53]. The temperature dependence of the saturation magnetization of the annealed samples prepared by both filling routes indicated a change of less

Electron interactions with the heteronuclear carbonyl precursor H₂FeRu₃(CO)₁₃ and comparison with HFeCo₃(CO)₁₂: from fundamental gas phase and surface science studies to focused electron beam induced deposition

• Ragesh Kumar T P,
• Paul Weirich,
• Lukas Hrachowina,
• Marc Hanefeld,
• Ragnar Bjornsson,
• Helgi Rafn Hrodmarsson,
• Sven Barth,
• D. Howard Fairbrother,
• Michael Huth and
• Oddur Ingólfsson

Beilstein J. Nanotechnol. 2018, 9, 555–579, doi:10.3762/bjnano.9.53

Design of polar self-assembling lactic acid derivatives possessing submicrometre helical pitch

• Alexej Bubnov,
• Cyril Vacek,
• Michał Czerwiński,
• Terezia Vojtylová,
• Wiktor Piecek and
• Věra Hamplová

Beilstein J. Nanotechnol. 2018, 9, 333–341, doi:10.3762/bjnano.9.33

• increase was observed with the temperature decrease. The difference in the temperature dependence of the helical pitch (KL 3/5 with respect to other studied compounds) can be associated with a different helical twist sense, which in turn depends on the change of the concentration of different conformers

• pitch length p was determined on homeotropically aligned samples under study placed on a single glass plate while leaving the other surface of the sample free. The measurements of the helical pitch p were based on the selective light reflection phenomenon [60]. The measurements of the temperature

• dependence of the helical pitch p were done using light at normal incidence, i.e., penetrating the sample along the helical pitch. To confirm the SmC* phase existence and to identifying the observation of the half pitch or full pitch selective reflection band, the spectrum were measured at oblique incidence

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

Alternating current magnetic susceptibility of a ferronematic

• Natália Tomašovičová,
• Jozef Kováč,
• Veronika Gdovinová,
• Nándor Éber,
• Tibor Tóth-Katona,
• Jan Jadżyn and
• Peter Kopčanský

Beilstein J. Nanotechnol. 2017, 8, 2515–2520, doi:10.3762/bjnano.8.251

• prepared sample was measured in the same experimental geometry as the magnetization curves. An ac magnetic field of 1 Oe was applied at a frequency of f = 10 Hz. To measure the temperature dependence of χ, the sample was first heated to 315 K (isotropic phase), then slowly cooled down to the nematic phase

• increased excitation of spin waves. The decrease of the ac susceptibility with the temperature is related to the decrease of magnetization. Therefore, the absence of a temperature dependence of χ′ at the lower concentration of MNPs [27] is a strong indication of the absence of interaction between MNPs. (v

• . Magnetization curve of the powder of Fe3O4 magnetic nanoparticles, measured at 285 K. Temperature dependence of the capacitance of 6CB and of two ferronematic samples with different MNP concentrations, . Magnetization curves of neat 6CB and the FN with a MNP concentration of = 10−4 in the nematic phase, as

Changes of the absorption cross section of Si nanocrystals with temperature and distance

• Michael Greben,
• Petro Khoroshyy,
• Sebastian Gutsch,
• Daniel Hiller,
• Margit Zacharias and
• Jan Valenta

Beilstein J. Nanotechnol. 2017, 8, 2315–2323, doi:10.3762/bjnano.8.231

• the function presented in Equation 20 (Figure 4b) for our ML structures. Temperature dependence of the ACS Contrary to the common assumption, the ACS should be generally considered as temperature-dependent [5][29]. There are two mechanisms responsible for this dependence. First, for the phonon

• [9][10] to the absorption coefficient α normalized by the volume concentration of NCs, cV, (σ = α/cV). Finally, by substituting Equation 23 into the approximation presented by Kovalev et al. [29], the temperature dependence of the ACS at a fixed energy of absorbed photons, , can be estimated as: The

• ACS of the SL sample is expected to be comparable with the values of ML samples with separation barriers of 1 and 1.6 nm. In contrast to Equation 24, the temperature dependence of ACS of both samples occurred to be well described by a simple exponential function in a broad interval of temperatures

Substrate and Mg doping effects in GaAs nanowires

• Perumal Kannappan,
• Nabiha Ben Sedrine,
• Jennifer P. Teixeira,
• Maria R. Soares,
• Bruno P. Falcão,
• Maria R. Correia,
• Nestor Cifuentes,
• Emilson R. Viana,
• Marcus V. B. Moreira,
• Geraldo M. Ribeiro,
• Alfredo G. de Oliveira,
• Juan C. González and
• Joaquim P. Leitão

Beilstein J. Nanotechnol. 2017, 8, 2126–2138, doi:10.3762/bjnano.8.212

• level structure of the nanowires, a detailed investigation on the temperature-dependent PL is required. Before the presentation of the results, we will mention briefly the common temperature dependence of the bandgap in a semiconductor. As the temperature increases, the thermal expansion coefficient of

• the lattice and the electron–phonon interaction promote the broadening and the redshift of the energy levels, which leads to a reduction of the bandgap [46][62][63]. Among the several theoretical models available in the literature, one that probably better describes the temperature dependence of the

• carriers dynamics. This is very important for the intended photovoltaic applications of these nanowires, in which the collection of charge carriers is a key issue. On average, for growth on the GaAs(111)B substrate, the temperature dependence of the PL showed the thermal activation of non-radiative de

Near-infrared-responsive, superparamagnetic Au@Co nanochains

• Varadee Vittur,
• Arati G. Kolhatkar,
• Shreya Shah,
• Irene Rusakova,
• Dmitri Litvinov and
• T. Randall Lee

Beilstein J. Nanotechnol. 2017, 8, 1680–1687, doi:10.3762/bjnano.8.168

• temperature dependence of the magnetization for nanochains was measured in an applied field of 100 Oe from 0 to 400 K. Figure 8a shows the zero-field-cooling (ZFC) and field-cooled (FC) measurements of the Au@Co nanochains. The sharp maximum in the ZFC curve demonstrated the blocking behavior of the

Formation of ferromagnetic molecular thin films from blends by annealing

• Peter Robaschik,
• Ye Ma,
• Salahud Din and
• Sandrine Heutz

Beilstein J. Nanotechnol. 2017, 8, 1469–1475, doi:10.3762/bjnano.8.146

• moment per MnPc we can further confirm that no significant amount of phthalocyanine molecules have been sublimed during the annealing process. For further analysis the temperature dependence of the magnetisation (Figure 5a) has been measured at fields of 20 and 40 mT for both field cooled (FC) and zero

Deposition of exchange-coupled dinickel complexes on gold substrates utilizing ambidentate mercapto-carboxylato ligands

• Martin Börner,
• Laura Blömer,
• Marcus Kischel,
• Peter Richter,
• Georgeta Salvan,
• Dietrich R. T. Zahn,
• Pablo F. Siles,
• Maria E. N. Fuentes,
• Carlos C. B. Bufon,
• Daniel Grimm,
• Oliver G. Schmidt,
• Daniel Breite,
• Bernd Abel and
• Berthold Kersting

Beilstein J. Nanotechnol. 2017, 8, 1375–1387, doi:10.3762/bjnano.8.139

• crystals of 7. Temperature dependence of the effective magnetic moment μeff (per dinuclear complex) for 7 (open triangles) and 8 (open squares). The solid lines represent the best fits to Equation 2. AFM topography characteristics considering a 1 × 1 μm2 area, after deposition of [Ni2L(HL5)](ClO4) (7) on

Charge transport in organic nanocrystal diodes based on rolled-up robust nanomembrane contacts

• Vineeth Kumar Bandari,
• Lakshmi Varadharajan,
• Longqian Xu,
• Abdur Rehman Jalil,
• Mirunalini Devarajulu,
• Pablo F. Siles,
• Feng Zhu and
• Oliver G. Schmidt

Beilstein J. Nanotechnol. 2017, 8, 1277–1282, doi:10.3762/bjnano.8.129

• slopes the change-over of which occur at around 125 K, as shown in Figure 3b. The curves for T > 125 K (left part) show more pronounced temperature dependence, which indicates that thermal activation plays an important role during the transport [37]. Both the left and right regions of Figure 3b are well

Growth, structure and stability of sputter-deposited MoS₂ thin films

• Reinhard Kaindl,
• Bernhard C. Bayer,
• Roland Resel,
• Thomas Müller,
• Viera Skakalova,
• Gerlinde Habler,
• Rainer Abart,
• Alexey S. Cherevan,
• Dominik Eder,
• Maxime Blatter,
• Fabian Fischer,
• Jannik C. Meyer,
• Dmitry K. Polyushkin and
• Wolfgang Waldhauser

Beilstein J. Nanotechnol. 2017, 8, 1115–1126, doi:10.3762/bjnano.8.113

• conductivity in all our investigated PVD films was somewhat unexpected. Further work, including measurements of the temperature dependence of the film conductivities, will be necessary to confirm the exact nature of the conduction mechanisms in our PVD MoS2 films [45]. Possible reasons for the unexpected

Fully scalable one-pot method for the production of phosphonic graphene derivatives

• Kamila Żelechowska,
• Marta Prześniak-Welenc,
• Marcin Łapiński,
• Izabela Kondratowicz and
• Tadeusz Miruszewski

Beilstein J. Nanotechnol. 2017, 8, 1094–1103, doi:10.3762/bjnano.8.111

• −2 to 4.2 × 10−2 S·cm−2 in the measured temperature range) and increases with increasing temperature. Moreover, an exponential temperature dependence of conductivity was noticed. The red line presented in Figure 10 represents the fit of an Arrhenius model (σ ~ exp(−T−1)). The good correlation between

• applied model and experimental results (R2 ≈ 0.998) indicates that the electrical conductivity at higher temperatures of the analyzed GO-P sample can be well described by an Arrhenius temperature dependence model for semiconductors. The results presented in Figure 10 clearly shows that the phosphonated

• GO (A and B) and GO-P (C and D). TG and DTG curves of A) GO and B) GO-P. DSC and DDSC curves of A) GO sample and B) GO-P. The TG curves are the same as in Figure 8. The temperature dependence of the total surface conductivity of the analyzed GO-P sample. Supporting Information Supporting Information

BTEX detection with composites of ethylenevinyl acetate and nanostructured carbon

• Santa Stepina,
• Astrida Berzina,
• Gita Sakale and
• Maris Knite

Beilstein J. Nanotechnol. 2017, 8, 982–988, doi:10.3762/bjnano.8.100

• use of nanocarbons increases the detection range as well as the electrical conductivity of the chemiresistors and decreases the temperature dependence. Hybrid composites were made of poly(dimethyl siloxane) (PDMS) with nanocarbon black (NCB) and carbon nanotubes (CNT) as fillers and these composites

• showed reversible gas-sensing measurements on BTEX. They also point out that the increased electrical conductivity, decreased temperature dependence of conductivity, and stretchability will be useful in stretchable electronics. In our previous works [8][9][20][21][22][23], we determined that the EVA–CB

Tuning the spin coherence time of Cu(II)−(bis)oxamato and Cu(II)−(bis)oxamidato complexes by advanced ESR pulse protocols

• Ruslan Zaripov,
• Evgeniya Vavilova,
• Iskander Khairuzhdinov,
• Kev Salikhov,
• Violeta Voronkova,
• Mohammad A. Abdulmalic,
• Francois E. Meva,
• Saddam Weheabby,
• Tobias Rüffer,
• Bernd Büchner and
• Vladislav Kataev

Beilstein J. Nanotechnol. 2017, 8, 943–955, doi:10.3762/bjnano.8.96

• ). This suggests additional temperature dependent contributions to the stochastic modulation of the HF interaction in the studied complexes. Such contributions, which could explain the observed temperature dependence of Tm, may arise due to a random modulation of the HF interaction by a temperature

• dependence of the intensity of the echo signal for complex P1 at T = 30 K on a linear (main panel) and on a logarithmic scale (inset) measured with the primary echo (blue squares) and CPMG (red circles) protocols at X-band (a) and at Q-band (b). Temperature dependence of the phase relaxation time Tm of P1

• (P2) (Q-band) and at T = 20 K for the magnetic field oriented normal (90°) to the molecular plane. The difference of the line positions of the two spectra is due to the different g-factor of Cu for the studied samples gz(P1) = 2.184 [9] and gz(P2) = 2.159 [10]. Temperature dependence of the phase

Probing the magnetic superexchange couplings between terminal Cu^II ions in heterotrinuclear bis(oxamidato) type complexes

• Mohammad A. Abdulmalic,
• Saddam Weheabby,
• Francois E. Meva,
• Azar Aliabadi,
• Vladislav Kataev,
• Bernd Büchner,
• Frederik Schleife,
• Berthold Kersting and
• Tobias Rüffer

Beilstein J. Nanotechnol. 2017, 8, 789–800, doi:10.3762/bjnano.8.82

• . Experimental Section and Supporting Information File 1, giving thus errors in the determination of the molecular weight of the samples. Further insights into the magnetism of the studied samples can be obtained from the analysis of the temperature dependence of the static magnetic susceptibility χ = M/H. The

• . The temperature dependence of the static magnetization was measured in a temperature range T = 1.8–300 K and at µ0H = 1 T with this device. For these magnetic measurements, single crystals of the individual complexes were taken and gently heated (ca. 35 °C) overnight in vacuum to obtain materials free

• versus magnetic field M(H) of 3 at T = 1.8 K (symbols) together with the fit of M(H) to the Brillouin function with S = 1/2 according to Equation 1 (solid line). Temperature dependence of the magnetic susceptibility χ = M/H and of the corresponding inverse susceptibility χ−1 for 1 (symbols). The black

First examples of organosilica-based ionogels: synthesis and electrochemical behavior

• Andreas Taubert,
• Ruben Löbbicke,
• Barbara Kirchner and
• Fabrice Leroux

Beilstein J. Nanotechnol. 2017, 8, 736–751, doi:10.3762/bjnano.8.77

• finds an Arrhenius-type temperature dependence associated to high ion conductivity. Indeed an optimized composition, MBA40IL, exhibits an ionic conductivity of almost 10−2 S·cm−1 at 357 K (84 °C, the upper limit in this study). Figure 12 however shows that 84 °C is not the upper limit for this system

Diffusion and surface alloying of gradient nanostructured metals

• Zhenbo Wang and
• Ke Lu

Beilstein J. Nanotechnol. 2017, 8, 547–560, doi:10.3762/bjnano.8.59

• kinetics in the preformed GNS layers. Temperature dependence of the diffusion coefficients of Cr in the GNS Fe produced by SMAT and in the CG Fe, in comparison with those for the α-Fe lattice diffusion, the α-Fe GB diffusion and the diffusion in Fe–Cr alloy. Figure reproduced with permission from [31

Impact of contact resistance on the electrical properties of MoS₂ transistors at practical operating temperatures

• Filippo Giannazzo,
• Gabriele Fisichella,
• Aurora Piazza,
• Salvatore Di Franco,
• Giuseppe Greco,
• Simonpietro Agnello and
• Fabrizio Roccaforte

Beilstein J. Nanotechnol. 2017, 8, 254–263, doi:10.3762/bjnano.8.28

• main limiting factors for suitable device performance. Furthermore, to gain a deeper understanding of MoS2 FETs under practical operating conditions, it is necessary to investigate the temperature dependence of the main electrical parameters, such as the field effect mobility (μ) and the threshold

• determined and it was found to increase with T as RC proportional to T3.1. The contribution of RC to the extraction of μ and Vth was evaluated, showing a more than 10% underestimation of μ when the effect of RC is neglected, whereas the effect on Vth is less significant. The temperature dependence of μ and

• 373 K, which was explained in terms of electron trapping at MoS2/SiO2 interface states. Keywords: contact resistance; mobility; MoS2; temperature dependence; threshold voltage; Introduction Transition metal dichalcogenides (TMDs) are compound materials formed by the Van der Waals stacking of MX2

Electron energy relaxation under terahertz excitation in (Cd_1−xZn_x)₃As₂ Dirac semimetals

• Alexandra V. Galeeva,
• Ivan V. Krylov,
• Konstantin A. Drozdov,
• Anatoly F. Knjazev,
• Alexey V. Kochura,
• Alexander P. Kuzmenko,
• Vasily S. Zakhvalinskii,
• Sergey N. Danilov,
• Ludmila I. Ryabova and
• Dmitry R. Khokhlov

Beilstein J. Nanotechnol. 2017, 8, 167–171, doi:10.3762/bjnano.8.17

• range 4.2–300 K. The resistivity temperature dependence is typical for degenerate semiconductors: the resistivity decrease with decreasing temperature from 300 K to 20 K is followed by a further saturation at T < 20 K. Since the free electron concentration does not change, this resistivity variation is

• completely determined by the mobility temperature dependence. It is important to note that the free electron concentration in the samples studied differs by a factor of four. The low temperature mobility absolute values are very high and exceed 105 cm2/(V·s). The main tool of the study was the measurement of

Nanocrystalline TiO₂/SnO₂ heterostructures for gas sensing

• Barbara Lyson-Sypien,
• Anna Kusior,
• Mieczylaw Rekas,
• Jan Zukrowski,
• Marta Gajewska,
• Katarzyna Michalow-Mauke,
• Thomas Graule,
• Marta Radecka and
• Katarzyna Zakrzewska

Beilstein J. Nanotechnol. 2017, 8, 108–122, doi:10.3762/bjnano.8.12

• , the temperature dependence of R0/R follows R0 vs temperature, because R is almost constant. On the other hand, in the case of the TiO2-rich sample both R0 and R exhibit a similar temperature dependence, which leads to a gas response R0/R almost independent of the temperature. In order to study the

• ). The gas-sensor response S is defined in Equation 4. Dynamic changes in the electrical resistance, R, of: a) 90 mol % SnO2/10 mol % TiO2; b) 10 mol % SnO2/90 mol % TiO2 heterostructures upon interaction with 1100 ppm H2. τ denotes the recovery time. Temperature dependence of the electrical resistance

Sub-nanosecond light-pulse generation with waveguide-coupled carbon nanotube transducers

• Felix Pyatkov,
• Svetlana Khasminskaya,
• Vadim Kovalyuk,
• Frank Hennrich,
• Manfred M. Kappes,
• Gregory N. Goltsman,
• Wolfram H. P. Pernice and
• Ralph Krupke

Beilstein J. Nanotechnol. 2017, 8, 38–44, doi:10.3762/bjnano.8.5

• ,mod(T) presented in Figure 2b (red symbols). Since the limited detection range of the CCD camera allows for the detection of broadband CNT-emitted light only for hc/λ >> kT, the temperature dependence of Iintegrated,mod(T) can be described using Wien’s approximation of Planck’s law. The best fit to