Characterization and photocatalytic study of tantalum oxide nanoparticles prepared by the hydrolysis of tantalum oxo-ethoxide Ta₈(μ₃-O)₂(μ-O)₈(μ-OEt)₆(OEt)₁₄

• Subia Ambreen,
• N D Pandey,
• Peter Mayer and
• Ashutosh Pandey

Beilstein J. Nanotechnol. 2014, 5, 1082–1090, doi:10.3762/bjnano.5.121

• substances at 200–400 °C is caused by the decomposition of organic species inside the mesopores of the sample. Further the weight loss in the temperature range of 400–650 °C is due to a phase transition. An exothermic peak centered at 386.7 °C in the DTA curve supports the statements above. The observation

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

• heat exchange between the vapor and fine solid particles is neglected in comparison with the much more intensive (accompanied by a phase transition) heat exchange between the vapor and liquid. (4) The polymineral nature of the fine solid particle is taken into account in the following manner: The real

• 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

• the relationships of continuity of the fluxes of mass, momentum, and energy on the surface of the discontinuity: where the subscript “w” characterizes the values on both sides of the wave of phase transition, ρw << ρl, plw is the pressure on the edge of the bubble, and Qv(Tlw) is the specific steam

One pot synthesis of silver nanoparticles using a cyclodextrin containing polymer as reductant and stabilizer

• Arkadius Maciollek and
• Helmut Ritter

Beilstein J. Nanotechnol. 2014, 5, 380–385, doi:10.3762/bjnano.5.44

• period of several weeks. Furthermore the changes in the optical properties of the nanoparticles due to thermo induced volume phase transition behavior of the thermoresponsive cyclodextrin containing polymer 1 have been characterized by UV–vis spectroscopy. Keywords: cyclodextrin; polymer; silver

• properties of the polymer stabled silver nanoparticles 2 have been investigated. By heating the AgNP’s 2 above the lower critical solution temperature (LCST) of the NIPAM containing copolymer 1 (33 °C), a volume phase transition will take place, which should effect the optical and solution properties

• immobilization of polymer 1 on the metal nanoparticle 2 surface due to coordination of silver with the nitrogen atoms of the NIPAM residue respectively hydroxy group of the CD function in 1 [25]. This adsorption suppresses the volume phase transition at higher temperatures [15]. Furthermore the thermoresponsive

Nanoscale patterning of a self-assembled monolayer by modification of the molecule–substrate bond

• Cai Shen and
• Manfred Buck

Beilstein J. Nanotechnol. 2014, 5, 258–267, doi:10.3762/bjnano.5.28

• , the phase transition involved in the annealing is another process likely to contribute as discussed further below. Defects in the SAM are introduced by pulsing the STM tip. The extent of damage depends on the voltage, and a value of 4.5 V was used in this example, which generates defects about 6 nm in

Some reflections on the understanding of the oxygen reduction reaction at Pt(111)

• Ana M. Gómez-Marín,
• Ruben Rizo and
• Juan M. Feliu

Beilstein J. Nanotechnol. 2013, 4, 956–967, doi:10.3762/bjnano.4.108

• is attained, i.e. the butterfly, followed by a wide potential region in which no faradaic charge is transferred, was assumed to correspond to the formation of PtO from PtOH, as a phase transition that involves the adsorption of additional OHads. This increased coverage of PtOH would destabilize the

Controlling the near-field excitation of nano-antennas with phase-change materials

• Tsung Sheng Kao,
• Yi Guo Chen and
• Ming Hui Hong

Beilstein J. Nanotechnol. 2013, 4, 632–637, doi:10.3762/bjnano.4.70

• switching the phase states of a GST thin film can be easily accomplished by various well-developed methods, such as electric current, optical pumping and thermal stimulus [23][24]. In the near-infrared (NIR) range, a drastic change in the real part of the refractive index from the phase transition and low

• obtained from [17]. With these supposed material parameters carried out in the FDTD simulation, the corresponding refractive index values and the transmission spectra of a GST thin film at different intermediate states can be obtained by carefully selecting the proportion value m. The phase transition of a

• sputtered GST phase-change thin film was performed by a homogeneous heating on a hot-plate with a crystallization temperature of 135 °C. This constant temperature was set to provide a slow phase transition rate, which facilitated a finer control of the crystalline proportions of samples. As the heating time

Mapping of plasmonic resonances in nanotriangles

• Simon Dickreuter,
• Julia Gleixner,
• Andreas Kolloch,
• Johannes Boneberg,
• Elke Scheer and
• Paul Leiderer

Beilstein J. Nanotechnol. 2013, 4, 588–602, doi:10.3762/bjnano.4.66

• various total energies. Both femtosecond and picosecond pulses induce a phase transition in GST, changing the film from a highly reflecting crystalline into an optically absorbing amorphous state, when the local fluence exceeds a certain threshold fluence Ith,GST. As illustrated in Figure 2b, this leads

Plasticity of Cu nanoparticles: Dislocation-dendrite-induced strain hardening and a limit for displacive plasticity

• Antti Tolvanen and
• Karsten Albe

Beilstein J. Nanotechnol. 2013, 4, 173–179, doi:10.3762/bjnano.4.17

• nanowires at high stresses and zero temperatures [4]. Non-close-packed nanostructures have been reported to deform by phase-transitions to a higher density phase. A limit of displacive plasticity leading to a phase-transition path was reported for Si nanospheres [5] concluding that in ultrasmall structures

• , where dislocation activity is suppressed, this path should dominate. Also in the tensile testing of twinned fcc Fe nanowires, a phase-transition path was reported as the dislocation activity is suppressed by the dense twin boundaries [6]. These findings raise a question: could there also be a size limit

• ? In the fcc phase, the material is at the maximum possible density and amorphisation cannot release the pressure by contraction of the atomic volume. However, in the observed surface phase transition the amorphous phase is effectively at zero pressure, and beyond the pressure limit of ca. 20 GPa the

Hydrogen-plasma-induced magnetocrystalline anisotropy ordering in self-assembled magnetic nanoparticle monolayers

• Alexander Weddemann,
• Judith Meyer,
• Anna Regtmeier,
• Irina Janzen,
• Dieter Akemeier and
• Andreas Hütten

Beilstein J. Nanotechnol. 2013, 4, 164–172, doi:10.3762/bjnano.4.16

• present in either sample. According to the XRD data, no phase transition during plasma exposure is observed. This is in accordance with the findings by Sun and Murray [22] who reported the transitions between the different crystallographic phases ε-Co → hcp-Co and hcp-Co → fcc-Co to have activation

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

• to low temperatures. This indicates that the phase transformation from an amorphous to the ordered L10 phase is accompanied by a corresponding phase transition from a superparamagnetic to a moderately hard ferromagnetic state. The overall magnetic properties of these samples depend strongly on the

Modeling noncontact atomic force microscopy resolution on corrugated surfaces

• Kristen M. Burson,
• Mahito Yamamoto and
• William G. Cullen

Beilstein J. Nanotechnol. 2012, 3, 230–237, doi:10.3762/bjnano.3.26

• were performed before imaging of the SiO2. Si(111) samples (Figure 1c) were cleaned in UHV by the standard procedure with repeated flashing at 1530 K, followed by slow cooling through the (1 × 1)-to-(7 × 7) phase transition [30]. NC-AFM measurements were performed with commercially available

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

• –Cowley short-range order parameters up to 8th neighbors for a Pt–Rh nanoparticle with 9201 atoms (corresponding to a diameter of 7.8 nm) in equilibrium versus temperature. The phase transition at T ≈ 226 K is clearly visible. Comparison of the (lower points) and (upper points) WC-order parameters

• 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

• parameters in Figure 10. Comparison of the WC-order parameters (lower points) and (upper points). The Pt concentration is chosen such that for all particles the phase transition is observed at the maximum critical temperature of the 40-phase. In contrast to the in Figure 8, the in this plot are biased

Investigation on structural, thermal, optical and sensing properties of meta-stable hexagonal MoO₃ nanocrystals of one dimensional structure

• Angamuthuraj Chithambararaj and
• Arumugam Chandra Bose

Beilstein J. Nanotechnol. 2011, 2, 585–592, doi:10.3762/bjnano.2.62

• oxide; one dimensional rod; phase transition; Introduction Considerable research interest has been focused on metastable nanocrystalline materials due to their unusual and enhanced properties as compared to their bulk counterparts. Synthesis of metastable nanocrystals with controlled size and shape has

• (HRTEM) images and EELS spectrum were acquired by means of a JEOL model JEM FX II 2000 instrument. The thermal behavior was analyzed by means of an EXSTAR6200 thermal analyzer at a heating rate of 10 °C/min, from room temperature to 550 °C in air. The weight loss and the corresponding phase transition

Surface induced self-organization of comb-like macromolecules

• Konstantin I. Popov,
• Vladimir V. Palyulin,
• Martin Möller,
• Alexei R. Khokhlov and
• Igor I. Potemkin

Beilstein J. Nanotechnol. 2011, 2, 569–584, doi:10.3762/bjnano.2.61

• of side chains is a phase transition in a quasi one-dimensional object. Hence, an ordered state is impossible according to Landau theorem [54]. In all the cases under consideration (poor, theta, and good solvents, and various forces of interaction between units of side chains of various types

• -trivial morphologies as arrowhead, zigzag, wavy lamellar and smectic bilayers [79][80]. For more details, see recent review [81]. LC phase transition temperatures were found to be close to the homopolymer case. However, in several examples stabilization of liquid-crystalline and microphases influenced

Switching adhesion forces by crossing the metal–insulator transition in Magnéli-type vanadium oxide crystals

• Bert Stegemann,
• Matthias Klemm,
• Siegfried Horn and
• Mathias Woydt

Beilstein J. Nanotechnol. 2011, 2, 59–65, doi:10.3762/bjnano.2.8

• , Universitätsstr. 1, D-86135 Augsburg, Germany 10.3762/bjnano.2.8 Abstract Magnéli-type vanadium oxides form the homologous series VnO2n-1 and exhibit a temperature-induced, reversible metal–insulator first order phase transition (MIT). We studied the change of the adhesion force across the transition temperature

• force when crossing the MIT temperature and correlate this behavior to the corresponding phase transition. Results and Discussion Adhesion force measurements were carried out on the cleavage planes of the vanadium oxide both at room temperature (298 K) and at an appropriate temperature beyond the MIT

• undergo no phase transition neither when the sample is cooled down nor when heated up. Rather it maintains its metallic state. Due to this feature the V7O13 phase acted as reference sample in order to prove that the observed jump in the adhesion force is not simply a temperature-related artifact but

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

• used to obtain quantitative information on the relaxation time. Such measurements on samples of interacting nanoparticles have shown that the relaxation time diverges in the same manner as in a spin glass, when the sample is cooled towards the phase transition temperature T0 [10][14][16][17][18], i.e

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

• ferromagnetic metals [1][2][3][4]. More surprisingly, the study of small Rh NPs revealed a paramagnetic to ferromagnetic phase transition induced by size reduction for clusters containing less than 40 atoms [5]. Band structure calculations have investigated the role of size reduction and demonstrated that it

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

• NPs [19] and spherical shape is the energetically favourable configuration. Evidence of NPs melting has been also reported for irradiated Au NPs [15][30]. Bulk CoPt alloy has a phase transition at 825 °C between the L10 ordered structure at low temperature and the disordered FCC structure at high

• temperature. As previously reported [9], this phase transition temperature decreases with particle size; however, such a size effect only occurs in sub-3 nm CoPt NPs. It can then be considered that the phase transition temperature for NPs larger than 10 nm is similar to the bulk phase transition temperature

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

• for systems which undergo a phase transition and thereby improves their magnetic properties such as in the cases of FePt or CoPt NPs which are of technological interest due to their high magnetocrystalline anisotropy in the L10 phase. However, it has mostly been observed that the as-prepared particles

• the XMCD and hysteresis loops were always measured in out-of-plane geometry. Moreover, our home-built plasma etching system can be attached to the high-field end-station which allows full in situ sample manipulation and characterization [32]. 3.3.1 Tracking the phase transition in FePt nanoparticles