Search results
Search for "alloy" in Full Text gives 201 result(s) in Beilstein Journal of Nanotechnology. Showing first 200.
Effects of swift heavy ion irradiation on structural, optical and photocatalytic properties of ZnO–CuO nanocomposites prepared by carbothermal evaporation method
Beilstein J. Nanotechnol. 2015, 6, 928–937, doi:10.3762/bjnano.6.96
- irradiated at fluences of 3 × 1013 and 1 × 1014 ions/cm2 are estimated to be 14.2 nm, 14.6 nm and 15.7 nm, respectively. It can be clearly seen that the average crystallite size of ZnO increases with increase in ion fluence. In addition to ZnO and CuO, nanostructured Cu–Zn alloy, Cu5Zn8 [JCPDS no. 71-0397
- ] were also observed, as can be seen from Figure 2. The Cu–Zn alloy is more prominently seen in the case of pristine sample. In the swift heavy ion irradiated samples the peaks corresponding to Cu–Zn alloy nanoparticles get increasingly diminished in intensity with increase in fluence. The UV–visible
- evaporation of ZnO and Cu, combined with annealing. FESEM studies showed the presence of ZnO nanosheets and nanorods, which are formed by Cu–Zn alloy nanodroplets assisted oriented attachment of ZnO nanoparticles. The effects of swift heavy ion irradiation on the structural, optical, and photocatalytic
Mapping of elasticity and damping in an α + β titanium alloy through atomic force acoustic microscopy
Beilstein J. Nanotechnol. 2015, 6, 767–776, doi:10.3762/bjnano.6.79
- . Physikalisches Institut, Georg-August-Universität, Friedrich Hund Platz 1, D-37077 Göttingen, Germany 10.3762/bjnano.6.79 Abstract The distribution of elastic stiffness and damping of individual phases in an α + β titanium alloy (Ti-6Al-4V) measured by using atomic force acoustic microscopy (AFAM) is reported
- cantilever with damped flexural modes. The cantilever dynamics model considering damping, which was proposed recently, has been used for mapping of indentation modulus and damping of different phases in a metallic structural material. The study indicated that in a Ti-6Al-4V alloy the metastable β phase has
- GPa. The type and amount of various phases formed during thermal/thermo-mechanical treatments influence both the mechanical as well as the elastic properties of α + β titanium alloys [1]. By varying the volume fractions of the two phases present in the alloy, various combinations of strength and
Influence of gold, silver and gold–silver alloy nanoparticles on germ cell function and embryo development
Beilstein J. Nanotechnol. 2015, 6, 651–664, doi:10.3762/bjnano.6.66
- fertility parameters deteriorated after co-incubation with ligand free gold nanoparticles. However, the effect could be alleviated by bio-coating the nanoparticles, which even applies to silver and silver-rich alloy nanoparticles. The most sensitive test system appeared to be in vitro oocyte maturation
- showing a dose-dependent response towards protein (BSA) coated gold–silver alloy and silver nanoparticles leading up to complete arrest of maturation. Recent biodistribution studies confirmed that nanoparticles gain access to the ovaries and also penetrate the blood–testis and placental barrier. Thus, the
- to nanoscale particles”. The aim was to study the impact of gold and silver nanoparticles, and to a degree gold–silver alloy nanoparticles, on spermatozoa, oocytes and embryos in vitro using murine as well as bovine and porcine models (Figure 1) [49][50][51]. The nanoparticles used in our studies
Influence of grain size and composition, topology and excess free volume on the deformation behavior of Cu–Zr nanoglasses
Beilstein J. Nanotechnol. 2015, 6, 537–545, doi:10.3762/bjnano.6.56
- properties of Cu–Zr nanoglasses (NGs) is investigated by molecular dynamics simulations using two model glasses of different alloy composition, namely Cu64Zr36 (Cu-rich) and Cu36Zr64 (Zr-rich). When the grain size is increased, or the fraction of interfaces in these NGs is decreased, we find a transition
- investigate if the plastic behavior of NGs changes with glass composition. Finally, the impact of the thermal relaxation of the glass–glass interface is studied. For this, two model glasses of different alloy composition are used, namely Cu64Zr36 (Cu-rich) and Cu36Zr64 (Zr-rich). All simulations are carried
- -centered FI [0,0,12,0] because this polyhedron is known to be the key structural motif in amorphous Cu–Zr alloy, characterized by a high packing density [21] and high shear resistance [22]. For modeling the NG microstructure, a 2D array of columnar grains with a hexagonal cross section is used. The grains
Filling of carbon nanotubes and nanofibres
Beilstein J. Nanotechnol. 2015, 6, 508–516, doi:10.3762/bjnano.6.53
- within the core of a filled MWCNT. This was achieved by first filling a MWCNT with iron, cobalt, nickel, or an iron–cobalt alloy using capillary action. Following this step, the sample was placed inside a transmission electron microscope (with the sample stage temperature set at 600 °C) and subjected to
Electrical properties of single CdTe nanowires
Beilstein J. Nanotechnol. 2015, 6, 444–450, doi:10.3762/bjnano.6.45
- a well-established method of plating conductive substrates with a specific metal or alloy. During the last decades, semiconductor electrodeposition became more and more attractive, as it may represent a viable alternative to more expensive fabrication methods [14][15][16]. CdTe electroplating is an
Materials and characterization techniques for high-temperature polymer electrolyte membrane fuel cells
Beilstein J. Nanotechnol. 2015, 6, 68–83, doi:10.3762/bjnano.6.8
- . To reduce the noble-metal loading of a fuel cell, platinum alloy catalysts such as PtNi and PtCo may be used. However, the stability of these Pt alloy catalysts is questionable partially because, under fuel cell operating conditions, transition metals such as nickel and cobalt are expected to form
- oxides or hydroxides that tend to dissolve from the electrode surface. Nevertheless, carbon-supported platinum/transition metal alloy catalysts are often used in conventional LT-PEMFCs as well as PAFCs. There is strong experimental evidence that platinum alloys outperform pure platinum catalysts [41][42
- the interatomic Pt–Pt distance [43]. Other researchers have suggested that the alloy layer beneath the platinum skin increases the d-band vacancy of the platinum itself improving, therefore, the oxygen reduction reaction [20]. A great deal of research on this subject was carried out from 1970’s until
Bright photoluminescence from ordered arrays of SiGe nanowires grown on Si(111)
Beilstein J. Nanotechnol. 2014, 5, 2498–2504, doi:10.3762/bjnano.5.259
- having an Orsay Physics mass filtered ion column operated at 30 keV. A liquid metal alloy ion source (LMAIS) of Au4Si ([Si] = 19%, [Au] = 81%) heated at 450 °C was used for the milling step; a Au2+ or Si+ ion beam was selected independently by a Wien filter. The patterns in the Si/SiO2 substrate were
- transformation from the small Au nanoclusters located within the SiO2-cover-free nanopits to the Au0.18Si0.82 eutectic alloy is obtained by thermal annealing at 550 °C for 30 min. The annealing and growth experiments were performed in the MBE growth chamber of a Riber SIVA32 system with a base pressure of 10−11
- volume of 0.006 µm3) and thus the carriers have to be recombining efficiently within the wires to produce this light emission at the SiGe-alloy band gap energy. We know from earlier studies of SiGe etched wires [32] and dots [33] that just the spatial confinement of carriers is sufficient to produce the
Si/Ge intermixing during Ge Stranski–Krastanov growth
Beilstein J. Nanotechnol. 2014, 5, 2374–2382, doi:10.3762/bjnano.5.246
- minimization of the surface energy, the strain energy, the alloy mixing energy and the configurational entropy [22]. In the case of a pure Ge dome island (no intermixing with Si), the stress was shown to be compressive in the interior of the island, and tensile at the edges of the island [34]. Thus, in the
Biopolymer colloids for controlling and templating inorganic synthesis
Beilstein J. Nanotechnol. 2014, 5, 2129–2138, doi:10.3762/bjnano.5.222
- ] demonstrated the synthesis of iron oxide nanoparticles in a semi-interpenetrating polymer network of alginate and poly(N-isopropylacrylamide). Gold and AuNi alloy gelatin nanocomposites were developed by Brayner et al. [84]. A gelatin network incorporating metallic nanoparticles was obtained after reduction of
- supercritical CO2 and subsequent calcination. Scaffold templating can also be achieved with starch and even with peptides. Thakore et al. [13] synthesized Cu, Ag, and Cu–Ag alloy nanoparticles in a matrix of starch through a green route and studied the antibacterial activity. Hexagonal silica platelets were
Carbon nano-onions (multi-layer fullerenes): chemistry and applications
Beilstein J. Nanotechnol. 2014, 5, 1980–1998, doi:10.3762/bjnano.5.207
- fluorescent-tagged CNOs (Scheme 8) were then used for in vitro fluorescence imaging, which will be discussed in the corresponding section of this review article. Recently, Echegoyen et al. reported for the first time the alkylation of CNOs [42], which was achieved by a reductive process utilizing a Na–K alloy
- . CNOs were added to a previously prepared, deep-blue solution of the Na–K alloy in 1,2-dimethoxyethane under inert atmosphere affording a brownish dispersion. Then an excess of 1-bromohexadecane was added as electrophile and the alkylated CNO material (CNO-C16) could be recovered. TGA analysis and IR as
The impact of the confinement of reactants on the metal distribution in bimetallic nanoparticles synthesized in reverse micelles
Beilstein J. Nanotechnol. 2014, 5, 1966–1979, doi:10.3762/bjnano.5.206
- than the other, it will form the core. The metal which is reduced more slowly will be deposited onto this core, forming the outer layers, which results in a core–shell nanostructure. In contrast, a small difference between reduction rates of the two metals leads to an alloy. Third, this result was
Cathode lens spectromicroscopy: methodology and applications
Beilstein J. Nanotechnol. 2014, 5, 1873–1886, doi:10.3762/bjnano.5.198
- , Fe preferentially wets the Pd-covered parts of the striped template. Furthermore, at about 200 °C Fe and Pd rearrange to make a surface alloy with a Pd-rich surface layer. The magnetization of the FePd stripes was found to be along the direction perpendicular to the stripe axis, as shown in the XMCD
On the structure of grain/interphase boundaries and interfaces
Beilstein J. Nanotechnol. 2014, 5, 1603–1615, doi:10.3762/bjnano.5.172
- deformation in micro-grained and nanostructured pseudo-single phase as well as micro-duplex metallic materials, ceramics, ceramic composites, intermetallics, dispersion strengthened alloys and an alloy containing quasi-crystalline particles [53]. Very recently, it has been found to be useful for interpreting
Current state of laser synthesis of metal and alloy nanoparticles as ligand-free reference materials for nano-toxicological assays
Beilstein J. Nanotechnol. 2014, 5, 1523–1541, doi:10.3762/bjnano.5.165
- paragraph of this article highlights the recent progress concerning the synthesis of composition controlled alloy nanoparticles by laser ablation in liquids. Here, binary and ternary alloy nanoparticles with totally homogeneous elemental distribution could be fabricated and the composition of these
- particles closely resembled bulk implant material. Finally, the model AuAg was used to systematically evaluate composition related toxicological effects of alloy nanoparticles. Here Ag+ ion release is identified as the most probable mechanism of toxicity when recent toxicological studies with gametes
- , mammalian cells and bacteria are considered. Keywords: albumin; gold-silver; implant alloy; laser ablation; nickel-titanium; size control; wear debris; Introduction The widespread use of medical implants consisting of metals (e.g., gold coatings [1]) and alloys (e.g., NiTi, CoCr, stainless steel) [2][3][4
Liquid fuel cells
Beilstein J. Nanotechnol. 2014, 5, 1399–1418, doi:10.3762/bjnano.5.153
- alloy increases the reaction rate by more than one order of magnitude compared to pure Pt supposedly due to the formation of hydrous molybdenum oxide that reduces the surface poisoning by adsorbed CO [130]. Palladium-based electrocatalysts deliver higher power densities compared to platinum-based ones
- on carbon was comparable [157]. Nickel-0based electrocatalysts are the most active for hydrazine oxidation. An alloy with the composition Ni0.6Co0.4 was about 6 times more active than the pure Ni catalyst [155]. The design space of binary Ni–M (with M = Mn, Fe, Zn, La) and ternary Ni–Mn–Fe and Ni–Zn
- reduces the cell efficiency and poisons the cathode catalyst. A fuel cell with a Laves phase AB2 Zr–Ni based alloy and Pd/C as the anode catalyst, a Nafion® NRE-211 membrane and Pt/C as the cathode catalyst delivered a power density of 290 mW/cm2 at 60 °C [172]. The NaBH4 utilization was only 51% but
Synthesis, characterization, and growth simulations of Cu–Pt bimetallic nanoclusters
Beilstein J. Nanotechnol. 2014, 5, 1371–1379, doi:10.3762/bjnano.5.150
- randomly in the Cu lattice. A novel simulation method is applied to study the growth mechanism, which shows the formation of alloy structures in good agreement with the experimental evidence. The findings give insight into the formation mechanism of the nanosized Cu–Pt bimetallic catalysts. Keywords: Cu
- , heterostructures, and alloy nanocrystals, and this diversity potentiates the increase of the mass specific activity (MSA) of the nanoparticle while also minimizing the cost by using precious metals only in the surface of the particles. Thus, in order to attain a better control on shape, size and composition of the
- novel simulation method to study the growth mechanism of CuPt bimetallic nanoclusters; in particular, we explored the attaching of Pt atoms on Cu seeds by using grand-canonical Langevin dynamics (GCLD) simulations, which shows the formation of alloy structures in good agreement with empirical evidence
Magnesium batteries: Current state of the art, issues and future perspectives
Beilstein J. Nanotechnol. 2014, 5, 1291–1311, doi:10.3762/bjnano.5.143
Review of nanostructured devices for thermoelectric applications
Beilstein J. Nanotechnol. 2014, 5, 1268–1284, doi:10.3762/bjnano.5.141
- ][79][80], and rapidly diffused and applied by several other groups [81][82][83][84][85]. The VLS growth is based on the catalytic effect of metal (gold or iron) nanoparticles, deposited on a silicon substrate. At high temperatures, an eutectic alloy is formed among metal and Si, supplied by a silane
- (SiH4) flux (or others silicon-based gases). A precise calibration of silane flux and reaction temperature gives a supersaturation of the melt and induces a transformation from the liquid alloy phase to solid Si that crystallizes under the metal nanoparticle. In this way, crystalline silicon
Integration of ZnO and CuO nanowires into a thermoelectric module
Beilstein J. Nanotechnol. 2014, 5, 927–936, doi:10.3762/bjnano.5.106
- material for the probing tips, Chromel was used. Chromel is an alloy of nickel and chromium, which exhibits a positive absolute Seebeck coefficient of about 28.1 μV/K [39] and is commonly used with Alumel to form K-type thermocouples. The voltage ΔV, measured at the ends of the probing tips, is
Injection of ligand-free gold and silver nanoparticles into murine embryos does not impact pre-implantation development
Beilstein J. Nanotechnol. 2014, 5, 677–688, doi:10.3762/bjnano.5.80
- nanoparticles made from gold [26], silver [27][28][29][30], silver–palladium alloy [31], and silver–copper alloy [30] by in ovo injection. Interestingly, no abnormal development was observed, except a low-grade inflammation of the embryonic liver after exposure to AgCu alloy nanoparticles. In mammals, almost
Magnesiothermic conversion of the silica-mineralizing golden algae Mallomonas caudata and Synura petersenii to elemental silicon with high geometric precision
Beilstein J. Nanotechnol. 2014, 5, 554–560, doi:10.3762/bjnano.5.65
- ][14][23]. The formation of the mixed binary phase Mg2Si was also described in the literature, but the formation of the alloy phase occurs only as an intermediate that reacts in a subsequent step with silica to the products silicon and magnesium oxide [16]. These equations correspond to our results
Calibration of quartz tuning fork spring constants for non-contact atomic force microscopy: direct mechanical measurements and simulations
Beilstein J. Nanotechnol. 2014, 5, 507–516, doi:10.3762/bjnano.5.59
- precision. Recent achievements of this force spectroscopy method manifest in the identification of the chemical identity of single atoms in an alloy [2] or the measurement of the force applied during the controlled manipulation of molecules or atoms on a surface [3][4]. nc-AFM experiments at the atomic
Confinement dependence of electro-catalysts for hydrogen evolution from water splitting
Beilstein J. Nanotechnol. 2014, 5, 195–201, doi:10.3762/bjnano.5.21
- assembly for the cathode process during water splitting. A computational model was designed to determine how alloying elements control the fraction of H2 released during zirconium oxidation by water relative to the amount of hydrogen picked up by the corroding alloy. This model is utilized to determine the
- ] site (cf. Figure 1c) Indeed, Equation 6 was found to be decisive for the fraction of hydrogen atoms not forming H2 but being absorbed in the Zr alloy according to For completeness, a 1.1 eV/H2 drive to release H2 from the confining grain boundary was computed according to Utilization of the hydride
- -proton recombination channel (see Figure 1b), the correlation between the computed reaction energies for the HER, Equation 6, and the experimental hydrogen pick-up fractions (HPUF), i.e., the fraction of the hydrogen, which does not undergo hydrogen evolution but are instead picked-up by the alloy during
3D-nanoarchitectured Pd/Ni catalysts prepared by atomic layer deposition for the electrooxidation of formic acid
Beilstein J. Nanotechnol. 2014, 5, 162–172, doi:10.3762/bjnano.5.16
- film uniformly. This could be due to a lower surface energy between the Pd and the annealed substrate. It is even possible to form a Pd/Ni alloy if the NiO top layer appears only when the sample is exposed to air. The two different growth mechanisms demonstrate the strong influence of the substrate on
Other Beilstein-Institut Open Science Activities
