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

• and low platinum concentration. A decrease of platinum surface segregation with increasing global platinum concentration was observed, when a second, ordered phase is formed inside the core of the particle. The order–disorder transitions were analyzed in terms of the Warren–Cowley short-range order

• question of how to interpret a two-phase equilibrium in the particle, and the effects related to surface segregation are examined. Furthermore, we evaluate the Warren–Cowley short-range order (WC-SRO) parameters in order to investigate the order–disorder phase transitions in the particles. These parameters

• surface phase emerges at low concentrations of the segregating element. We conclude from the simulations that these features are likely to be found in ordering systems with a surface segregation tendency of one element. Short-range order and order–disorder transitions We calculated the short-range order

Self-assembled monolayers and titanium dioxide: From surface patterning to potential applications

• Yaron Paz

Beilstein J. Nanotechnol. 2011, 2, 845–861, doi:10.3762/bjnano.2.94

• disorder–order change for alkanephosphate SAMs on TiO2 supported the validity of the uniform growth mechanism, i.e., strong chemisorption of single molecules that once chemisorbed are incapable of surface diffusion. The dichroic ratio of the methylene antisymmetric stretching band, defined as the intensity

Direct monitoring of opto-mechanical switching of self-assembled monolayer films containing the azobenzene group

• Einat Tirosh,
• Enrico Benassi,
• Silvio Pipolo,
• Marcel Mayor,
• Michal Valášek,
• Veronica Frydman,
• Stefano Corni and
• Sidney R. Cohen

Beilstein J. Nanotechnol. 2011, 2, 834–844, doi:10.3762/bjnano.2.93

• hindrance requires close packing, thus some slight disorder in the film could be an enabling condition for the isomerization [11]. Molecular packing also governs the excitonic coupling between chromophores, which can strongly influence the conversion efficiency [12]. A variety of methods to monitor the cis

Dynamics of capillary infiltration of liquids into a highly aligned multi-walled carbon nanotube film

• Sławomir Boncel,
• Krzysztof Z. Walczak and
• Krzysztof K. K. Koziol

Beilstein J. Nanotechnol. 2011, 2, 311–317, doi:10.3762/bjnano.2.36

• . It is worth noting that the spread convolutes variations in graphitic quality at the atomic scale, with overall variations in CNT orientation, and more complex diffraction effects are observed as disorder increases [22]. The mean outer and inner diameters of CNTs as measured by TEM were 60 ± 25 and

Extended X-ray absorption fine structure of bimetallic nanoparticles

• Carolin Antoniak

Beilstein J. Nanotechnol. 2011, 2, 237–251, doi:10.3762/bjnano.2.28

• distribution function (PDF) of atoms around the absorber atom. To account for thermal or configurational disorder, the complex wavenumber p is introduced and should be used instead of k. The imaginary part of p represents losses of photoelectron coherence, which includes the mean free path and core-hole

Structural and magnetic properties of ternary Fe_1–xMn_xPt nanoalloys from first principles

• Markus E. Gruner and
• Peter Entel

Beilstein J. Nanotechnol. 2011, 2, 162–172, doi:10.3762/bjnano.2.20

• significant percentage of surface atoms with diameters of a few nanometers. Several authors have therefore argued that at small particle sizes ordering is suppressed due to surface-induced disorder and segregation [21][24]. Both effects can be related to a change in the effective pair interactions between the

• arrangement in the surface layers. Onion-ring and hybrid morphologies have been considered for other alloys [59][60][61] as well as for Fe–Pt in the context of surface induced disorder [24][62][63][64]. This has been verified very recently in a combined ab initio and Monte Carlo approach [65], while

• configuration the most favorable L10-type structure in this concentration range. However, as discussed above, for binary Fe–Pt such a configuration will effectively be suppressed by a small amount of disorder in the system, due to Fe or Mn occupying a Pt site and mediating an effective ferromagnetic interlayer

Superhydrophobicity in perfection: the outstanding properties of the lotus leaf

• Hans J. Ensikat,
• Petra Ditsche-Kuru,
• Christoph Neinhuis and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2011, 2, 152–161, doi:10.3762/bjnano.2.19

• lotus wax. The ‘long spacing’ peaks indicate a layer structure which is common in aliphatic waxes. The broad ‘short spacing’ peak at 2θ = 27° indicates a strong disorder in the lateral package of the molecules. Model of a wax tubule composed of layers of nonacosan-10-ol and nonacosanediol molecules. The

Pore structure and surface area of silica SBA-15: influence of washing and scale-up

• Jörg P. Thielemann,
• Frank Girgsdies,
• Robert Schlögl and
• Christian Hess

Beilstein J. Nanotechnol. 2011, 2, 110–118, doi:10.3762/bjnano.2.13

• all samples to exclude it as source for the observed disorder. Importantly, it was found that under the chosen conditions only the amount of solvent used in the washing process had a significant influence on the shape of the isotherm of the final product (Figure 4). To gain insight into the influence

• extent depends on the degree of modification, in particular, the number of narrowed sections created during washing. The height of the bulge in the desorption branch may therefore be used to estimate qualitatively the degree of disorder created by combinational washing with plenty of solvent. However

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

• correct stacking sequence. In this paper, we present lattice-based kinetic Monte-Carlo simulations of FePt nanoparticles that reveal the influence of free surfaces, bulk vacancies and interaction with a substrate on the disorder–order transition. After describing the methodology, the case of a free

• , however, no single domain particles are obtained and an elimination of the antiphase boundaries could not be observed within the time scales accessible by the simulations. Simulations including a crystalline support show that, even if strong interface segregation is assumed, no influence on the disorder

Review and outlook: from single nanoparticles to self-assembled monolayers and granular GMR sensors

• Alexander Weddemann,
• Inga Ennen,
• Anna Regtmeier,
• Camelia Albon,
• Annalena Wolff,
• Katrin Eckstädt,
• Nadine Mill,
• Michael K.-H. Peter,
• Jochen Mattay,
• Carolin Plattner,
• Norbert Sewald and
• Andreas Hütten

Beilstein J. Nanotechnol. 2010, 1, 75–93, doi:10.3762/bjnano.1.10

Flash laser annealing for controlling size and shape of magnetic alloy nanoparticles

• Damien Alloyeau,
• Christian Ricolleau,
• Cyril Langlois,
• Yann Le Bouar and
• Annick Loiseau

Beilstein J. Nanotechnol. 2010, 1, 55–59, doi:10.3762/bjnano.1.7

• gives an unprecedented opportunity to control the size and the shape of bimetallic nanoparticles without changing their composition. The mechanisms involved in the complete reshaping of the nanoparticle thin films are discussed and it is also shown that order-disorder phase transformations occur under

• ; nanosecond pulsed laser annealing; order-disorder transformation; Introduction Future high-density recording systems require 10 nm magnetic grains with a high magnetic anisotropy (Ku) to insure their thermal stability [1]. CoPt and FePt nanoparticles (NPs) in the chemically ordered L10 structure [2] are