Nanoscale particles in technological processes of beneficiation

• Sergey I. Popel,
• Vitaly V. Adushkin and
• Anatoly P. Golub'

Beilstein J. Nanotechnol. 2014, 5, 458–465, doi:10.3762/bjnano.5.53

• equation: If the temperature Tlw of the liquid at the edge with the vapor is less than the critical temperature Tcr of the van der Waals gas then the phase transition takes place at the bubble surface. Considering the edge of the bubble as a hydrodynamical discontinuity (a wave of phase transition) we use

• heat. If the liquid temperature at the interface with the vapor is higher than (or equal to) the critical temperature then the phase transition is absent and the relationships in Equation 7 are fulfilled at the interface (ml = mw) under the condition At the surface of the bubble there are two competing

Charge and spin transport in mesoscopic superconductors

• M. J. Wolf,
• F. Hübler,
• S. Kolenda and
• D. Beckmann

Beilstein J. Nanotechnol. 2014, 5, 180–185, doi:10.3762/bjnano.5.18

• and 1980s, mostly in the vicinity of the critical temperature. Much less attention has been paid to low temperatures and the role of the quasiparticle spin. Results: We report here on nonlocal transport in superconductor hybrid structures at very low temperatures. By comparing the nonlocal conductance

• but no spin. The quasiparticle excitations, however, may carry both charge and spin. Non-equilibrium charge transport in superconductors has been investigated intensely in the 1970s and 1980s, mostly in the vicinity of the critical temperature [8][9][10] and more recently also in the low-temperature

• , some experiments reported shorter time scales (sometimes by orders of magnitude) under similar conditions [21][22]. In contrast, our results are quantitatively consistent with the “old” knowledge obtained from experiments close to the critical temperature [23][24][25], as well as more recent low

Size-dependent phase diagrams of metallic alloys: A Monte Carlo simulation study on order–disorder transitions in Pt–Rh nanoparticles

• Johan Pohl,
• Christian Stahl and
• Karsten Albe

Beilstein J. Nanotechnol. 2012, 3, 1–11, doi:10.3762/bjnano.3.1

• prove to be useful in order to assign a critical temperature to the smooth phase transitions in this finite system. Method The refined BOS mixing model We use a standard Metropolis Monte Carlo algorithm that implements a simulation model that is closely related to the “Bond Order Simulation” (BOS

• ). Second, we adjusted the composition for each particle size to coincide with the maximum of the critical temperature, i.e., xPt = 0.595, 0.66, 0.69 for the 7.8, 4.3 and 3.1 nm particles (Figure 8). For clarity only the two parameters for 6th and 8th neighbors that show the strongest variation at the

• such that for all particles the phase transition is observed at the maximum critical temperature of the 40-phase. No shift in magnitude of the concentration-averaged parameters is seen as is the case for non-concentration-averaged in Figure 9. Compare also to the core constrained short-range order

Enhancement of the critical current density in FeO-coated MgB₂ thin films at high magnetic fields

• Andrei E. Surdu,
• Hussein H. Hamdeh,
• Imad A. Al-Omari,
• David J. Sellmyer,
• Alexei V. Socrovisciuc,
• Andrei A. Prepelita,
• Ezgi T. Koparan,
• Ekrem Yanmaz,
• Valery V. Ryazanov,
• Horst Hahn and
• Anatolie S. Sidorenko

Beilstein J. Nanotechnol. 2011, 2, 809–813, doi:10.3762/bjnano.2.89

• material, with a hexagonal crystal structure and a critical temperature of Tc = 39 K, raised a lot of questions about its transport properties. This strong type-II superconductor has a fairly high critical current density in zero magnetic field, i.e., up to Jc ~ 1.6 × 107 A/cm2 at 15 K [2]. This

• films, in order to avoid the strong suppression of the critical temperature of the film. The proximity effect of nanoparticles has a very small effect on the superconducting properties of our MgB2 thin films, reducing their critical temperature by about 1 K. Taking into account these ideas, we studied

• , and the other 4.28 × 4.84 mm2 piece remained uncoated for comparison measurements. The Ginzburg–Landau coherence length of our films was obtained from the slope of the upper critical magnetic field measurements, Bc2(T), close to the critical temperature, resulting in ξGL(0) = 3.0 nm [12]. We measured

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

• high concentrations of magnetic nanoparticles, which would be superparamagnetic if they were non-interacting, magnetic dipole interactions can result in ordering of the magnetic moments of the nanoparticles below a critical temperature T0, where [9] Systems of magnetic nanoparticles with only magnetic