Zeolites as nanoporous, gas-sensitive materials for in situ monitoring of DeNO_x-SCR

• Thomas Simons and
• Ulrich Simon

Beilstein J. Nanotechnol. 2012, 3, 667–673, doi:10.3762/bjnano.3.76

• sensor at the same time. By means of temperature-dependent impedance spectroscopy we found that the thermally induced NH3 desorption in H-form and in Fe-loaded zeolite H-ZSM-5 follow the same process, while a remarkable difference under DeNOx-SCR reaction conditions was found. The Fe-loaded catalyst

• performed a series of measurements to analyse the temperature-dependent impedance. Therefore, the nonsolvated samples were loaded with NH3 (100 ppmv NH3 in N2) at room temperature for 1 h and afterwards heated up to 500 °C, in steps of 5 °C (100–300 °C), 10 °C (300–400 °C) and 20 °C (400–500 °C). To observe

Focused electron beam induced deposition: A perspective

• Michael Huth,
• Fabrizio Porrati,
• Christian Schwalb,
• Marcel Winhold,
• Roland Sachser,
• Maja Dukic,
• Jonathan Adams and
• Georg Fantner

Beilstein J. Nanotechnol. 2012, 3, 597–619, doi:10.3762/bjnano.3.70

• deposited between Au/Cr contacts previously defined by standard lithographic means. The temperature-dependent measurements were performed in a 4He cryostat with variable temperature insert. In Figure 6 the results for the elemental composition of the deposits, as determined by energy dispersive X-ray

• reaching a well-defined minimum at a composition close to Pt2Si3. The temperature-dependent conductivity, which is shown in Figure 8, indicates for this composition and also for the composition PtSi a special form of thermally activated transport, which is commonly associated to a variable-range hopping

• experimentally demonstrated. Great care has therefore to be taken when this precursor in used. Secondly, FEBID structures from Co2(CO)8 can have a metal content of more than 95 atom % and show temperature-dependent transport properties reminiscent of dirty Co thin films in combination with soft-magnetic behavior

Spontaneous dissociation of Co₂(CO)₈ and autocatalytic growth of Co on SiO₂: A combined experimental and theoretical investigation

• Kaliappan Muthukumar,
• Harald O. Jeschke,
• Roser Valentí,
• Evgeniya Begun,
• Johannes Schwenk,
• Fabrizio Porrati and
• Michael Huth

Beilstein J. Nanotechnol. 2012, 3, 546–555, doi:10.3762/bjnano.3.63

• precursor [52][53]. A larger degree of grain boundary scattering in the spontaneously formed deposit, as well as a possibly higher carbon content may be the cause for this enhanced resistivity. We also performed temperature-dependent resistivity measurements (Figure 4a) as well as Hall effect measurements

• (Figure 4b) for the sample grown on the plasma-activated silica. The samples grown under pre-irradiation conditions are unstable under thermal stress and could not be measured below room temperature. The temperature-dependent resistivity shows a typical metallic behavior as expected for a dirty metal

Mesoporous MgTa₂O₆ thin films with enhanced photocatalytic activity: On the interplay between crystallinity and mesostructure

• Jin-Ming Wu,
• Igor Djerdj,
• Till von Graberg and
• Bernd M. Smarsly

Beilstein J. Nanotechnol. 2012, 3, 123–133, doi:10.3762/bjnano.3.13

• temperature-dependent X-ray scattering. Optimal activity was obtained when the mesoporous film was heated to 790 °C; at this temperature, crystallinity was significantly high, with MgTa2O6 nanocrystals of 1.6 nm in size (averaged over all reflections), and an ordered mesoporous structure was maintained. When

• , temperature-dependent structural analysis proved that mesoporosity itself is not sufficient to endow metal oxides with advanced physicochemical performance. Experimental section Film fabrication MgCl2 (47 mg; 99.99%, Aldrich) and Ta(OC2H5)5 (500 mg; 99.98%, Aldrich) were dissolved separately in ethanol (2 g

Substrate-mediated effects in photothermal patterning of alkanethiol self-assembled monolayers with microfocused continuous-wave lasers

• Anja Schröter,
• Mark Kalus and
• Nils Hartmann

Beilstein J. Nanotechnol. 2012, 3, 65–74, doi:10.3762/bjnano.3.8

• locally heat the substrate surface and initiate desorption or decomposition of the coating. Because of the strongly temperature-dependent desorption kinetics, the overall process is highly nonlinear in the applied laser power. For this reason, subwavelength patterning is feasible employing ordinary

• patterning technique. Because of the strongly temperature-dependent thermal conductivity of Si, surface-temperature profiles on Au/Si substrates are very narrow ensuring a particularly high lateral resolution. At a 1/e spot diameter of 2 µm, fabrication of subwavelength structures with diameters of 300–400

• absorption [11][12]: with and Note, I0, here and in the following, denotes the modified Bessel function of order zero. Moreover, Equation 3 takes into account the temperature-dependent thermal conductivity of Si. In the case of Au/glass substrates laser absorption is strictly limited to the thin Au layer

Nanostructured, mesoporous Au/TiO₂ model catalysts – structure, stability and catalytic properties

• Matthias Roos,
• Dominique Böcking,
• Kwabena Offeh Gyimah,
• Gabriela Kucerova,
• Joachim Bansmann,
• Johannes Biskupek,
• Ute Kaiser,
• Nicola Hüsing and
• R. Jürgen Behm

Beilstein J. Nanotechnol. 2011, 2, 593–606, doi:10.3762/bjnano.2.63

• the CO oxidation reaction, performed with a scanning mass spectrometer directly above the film, yielded reaction characteristics that are very close to those of highly dispersed Au/TiO2 catalysts at comparable reaction conditions, with an activation energy of 23.9 kJ·mol−1 and temperature-dependent

Simple theoretical analysis of the photoemission from quantum confined effective mass superlattices of optoelectronic materials

• Debashis De,
• Sitangshu Bhattacharya,
• S. M. Adhikari,
• A. Kumar,
• P. K. Bose and
• K. P. Ghatak

Beilstein J. Nanotechnol. 2011, 2, 339–362, doi:10.3762/bjnano.2.40

• properties, are based on the temperature-dependent carrier statistics in such materials. Plot of the normalized photoemission current density from QW effective mass superlattices of HgTe/Hg1−xCdxTe as a function of inverse magnetic field, in which the curves (a), (b) and (c) represent the perturbed three and

Dense lying self-organized GaAsSb quantum dots on GaAs for efficient lasers

• Thomas H. Loeber,
• Dirk Hoffmann and
• Henning Fouckhardt

Beilstein J. Nanotechnol. 2011, 2, 333–338, doi:10.3762/bjnano.2.39

• sample temperature TPL, giving a value of 0.08 nm/K for the temperature dependent peak shift. The FWHM is almost constant at 18 ± 3 nm. The peak of the larger dots shifts from 1.034 up to 1.059 µm, giving 0.14 nm/K, with a FWHM of 75 ± 16 nm. The weaker quantization in the larger dots leads to a stronger

• wavelength of λLaser = 0.909 µm (at j = 1.22 × jth) is very close to the expected wavelength. From temperature dependent threshold current measurements, characteristic temperatures of T0 = 476.8 K for the temperature range below 140 K, and T0 = 63.2 K above 140 K, were extracted. In principle, for different

Effect of large mechanical stress on the magnetic properties of embedded Fe nanoparticles

• Srinivasa Saranu,
• Sören Selve,
• Ute Kaiser,
• Luyang Han,
• Ulf Wiedwald,
• Paul Ziemann and
• Ulrich Herr

Beilstein J. Nanotechnol. 2011, 2, 268–275, doi:10.3762/bjnano.2.31

• . The stress is applied to the nanoparticles through expansion of the substrate during hydrogen loading. Experimental evidence for stress induced magnetic effects is presented based on temperature-dependent magnetization curves of superparamagnetic Fe particles. The results show the potential of the

• of static magnetization measurements have been presented showing large increases of the Mr/Ms ratio and a reduction of the saturation field of the nanoparticles. The temperature dependent magnetization curves obtained after field cooling are also influenced by the applied stress. The results may be

Manipulation of gold colloidal nanoparticles with atomic force microscopy in dynamic mode: influence of particle–substrate chemistry and morphology, and of operating conditions

• Samer Darwich,
• Karine Mougin,
• Akshata Rao,
• Enrico Gnecco,
• Shrisudersan Jayaraman and
• Hamidou Haidara

Beilstein J. Nanotechnol. 2011, 2, 85–98, doi:10.3762/bjnano.2.10

• adhesion between them. Similar thermal effects have been recognized in friction on hydrophilic surfaces measured with different scan velocities [42]. It is worth noting that during this temperature dependent manipulation no evident damage was observed on working areas. Figure 5b shows a logarithmic plot of

• similar behavior in, both, trend and activation barrier of the temperature-dependent mobility is observed for the hydrophilic OH-coated NPs. An explanation for this result may come at least partly from the complex behavior of the adsorbed (structural) water depending on temperature in the hydrophilic

Kinetic lattice Monte-Carlo simulations on the ordering kinetics of free and supported FePt L1₀-nanoparticles

• Michael Müller and
• Karsten Albe

Beilstein J. Nanotechnol. 2011, 2, 40–46, doi:10.3762/bjnano.2.5

• for simulating the dynamics of ordering. In the simulation of a bulk material, the vacancy concentration is fixed at while in a real system, a temperature dependent vacancy concentration of would be observed. In the latter case, the average vacancy formation energy in FePt alloys predicted by the

Magnetic interactions between nanoparticles

• Steen Mørup,
• Mikkel Fougt Hansen and
• Cathrine Frandsen

Beilstein J. Nanotechnol. 2010, 1, 182–190, doi:10.3762/bjnano.1.22

• close to θ = 0° and θ = 180°. The superparamagnetic relaxation time is given by the Néel–Brown expression [7][8] where kB is Boltzmann’s constant and T is the temperature. τ0 is on the order of 10−13–10−9 s and is weakly temperature dependent. In experimental studies of magnetic nanoparticles, the

Ultrafine metallic Fe nanoparticles: synthesis, structure and magnetism

• Olivier Margeat,
• Marc Respaud,
• Catherine Amiens,
• Pierre Lecante and
• Bruno Chaudret

Beilstein J. Nanotechnol. 2010, 1, 108–118, doi:10.3762/bjnano.1.13

• ], respectively. Interestingly, in low fields, for such an assembly of NPs, the susceptibility (χ = m/H) versus temperature follows a Curie law independent of the anisotropy [40]. It should be noted that this expression depends on MS and Keff which are both temperature dependent. The static ZFC-FC curves can be

Preparation and characterization of supported magnetic nanoparticles prepared by reverse micelles

• Ulf Wiedwald,
• Luyang Han,
• Johannes Biskupek,
• Ute Kaiser and
• Paul Ziemann

Beilstein J. Nanotechnol. 2010, 1, 24–47, doi:10.3762/bjnano.1.5