Primary crystallization and decomposition in the bulk amorphous alloy Zr41.2Ti13.8Cu12.5Ni10Be22.5 have been studied by small angle neutron scattering (SANS), transmission electron microscopy (TEM), differential scanning calorimetry (DSC). SANS data of samples annealed isothermally at 623 K exhibit an interference peak centered q=0.46 nm−1 after incubation time about 100 min. TEM DSC investigations confirm that respective periodic variation length density is due to formation nanocrystals...

The self-diffusivity of Be in the bulk metallic amorphous alloy ${\mathrm{Zr}}_{41.2}{\mathrm{Ti}}_{13.8}{\mathrm{Cu}}_{12.5}{\mathrm{Ni}}_{10}{\mathrm{Be}}_{22.5}$ is investigated. Below glass transition temperature data suggest a single atomic jump diffusion behavior Be. By taking into account change configurational entropy due to transition, we explain mechanism for supercooled liquid state (i.e., above transition)...

Triarylamine molecules appended with crown-ethers or carboxylic moieties form self-assembled supramolecular channels within lipid bilayers. Fluorescence assays and voltage clamp studies reveal that the self-assemblies incorporating crown ethers work as single for selective transport of K+ Rb+. The X-ray crystallographic structures confirm mutual columnar self-assembly triarylamines crown-ethers. dimensional fit cations 18-crown-6 leads to a partial dehydration formation alternating...

A S6-symmetric triarylamine-based macrocycle (i.e., hexaaza[16]paracyclophane), decorated with six lateral amide functions, is synthesized by a convergent and modular strategy. This shown to undergo supramolecular polymerization in o-dichlorobenzene, its nanotubular structure elucidated combination of spectroscopy microscopy techniques, together X-ray scattering molecular modeling. Upon sequential oxidation, spectroelectrochemical analysis the polymer suggests an extended electronic...

The nanocrystallization process of reactively sputtered thin amorphous Ta–Si–N films is investigated by anomalous small angle x-ray scattering (ASAXS) and diffraction (XRD). Changes in the microstructure Ta40Si14N46 films, density variations matrix, decomposition, formation, growth nanocrystals after vacuum anneals at different temperatures range between 800 1000 °C are observed results techniques compared. From a Fourier analysis ASAXS intensities nanostructure ternary system derived using...

AbstractThe concept of energy is one key component science education curricula worldwide. While it still being taught in many classrooms from a mainly conceptual knowledge perspective, the need to frame as socioscientific issue and implement context citizenship for sustainable development, getting more explicit. As we will be faced with limited fossil fuels consequences global climate change future, students have supported becoming literate citizens who are able reach informed energy-related...

We report a combination of analytical transmission electron microscopy, small angle neutron scattering, and studies magnetic properties the glass-forming alloy Nd60Fe30Al10. These investigations show existence an in situ formed finely dispersed nanocrystalline Nd-rich phase embedded Fe-rich glassy matrix bulk sample. The crystalline forms extended network over whole sample but its volume fraction is compared to that compact phase. Small scattering data exhibit power law behavior with...

Be diffusivity data in the bulk metallic glass forming alloy Zr46.7Ti8.3Cu7.5Ni10Be27.5 are reported for temperatures between 530 and 710 K, extending 85 K into supercooled liquid state of alloy. At transition temperature Tg, a change dependence is observed, above Tg increases more quickly with than below. The can be described by modified Arrhenius expression based on diffusion mechanism suggested earlier. comparison viscosity reveals breakdown Stokes–Einstein relation, indicating...

A recently developed large number of bulk glass-forming alloys, known as metallic glasses, offer new opportunities for engineering applications and basic research on the nature glassy undercooled liquid states in metals. This text gives a short review glasses their properties, focusing Vitreloy™alloys which belong to best-investigated group systems.

We report on a small-angle x-ray-scattering (SAXS) and differential scanning calorimetry study of phase separation crystallization in rapidly quenched amorphous ${\mathrm{Mg}}_{62}{\mathrm{Cu}}_{25}{\mathrm{Y}}_{10}{\mathrm{Li}}_{3}$ alloy samples. Differential demonstrates the occurrence grain growth upon isothermal annealing these samples at 135 \ifmmode^\circ\else\textdegree\fi{}C. The SAXS studies show presence large inhomogeneities even as-prepared that is attributed to undercooled...

We demonstrate the use of silicon double-paddle oscillators for study mechanical properties thin films in temperature range 300–673 K under ultrahigh vacuum conditions. It is shown that even at these temperatures damping coefficient Q−1 one particular eigenmode bare paddle lower than 10−5 and explained through thermoelastic damping. This small background provides a sufficient sensitivity investigations above room temperature. As an application, shear modulus internal friction are presented...

The magnetic properties and microstructure of glassy Nd60Fe30Al10 splat-quenched samples have been investigated by small-angle neutron scattering, Mössbauer spectroscopy, vibrating sample magnetometry. presence chemical inhomogeneities in the amorphous is evidenced scattering which indicates a complex network atom clusters with an average diameter 15 nm. These results are confirmed magnetization measurements show coexistence two phases different ordering temperatures indicate separation...

The current dropout rate in physics studies Germany is about 60%, with the majority of dropouts occurring first year. Consequently, study entry phase poses a significant challenge for many students. Students’ stress perceptions can provide more profound insights into processes and challenges during that period. In panel featuring 67 measuring points involving up to 128 participants at each point, we investigated students’ perceived questionnaire (PSQ), identified underlying sources stress,...

Zusammenfassung: Diskutiert werden methodische Überlegungen zur Anwendbarkeit des narrativ-biografischen Interviews mit Blick auf die frühe Kindheit – einer Biografie in „statu nascendi“ der aus emotionalen und kognitiven Verarbeitung Erlebens Erzählungen erste biografische Erfahrungen entstehen.

Synthesis of the first N-lithiated cyanophosphanide complexes 5a−c was achieved via reaction complex 1 with tBuLi/12-crown-4, NaN(SiMe3)2/15-crown-5, or KOtBu/18-crown-6 at low temperature. Compounds were isolated and fully characterized by NMR IR spectroscopy elemental analysis. The structure 5a, as established X-ray diffraction studies, revealed that lithium is coordinated to nitrogen oxygen centers (of crown ether unit). This geometry 5a best described a phosphanide isomeric...

Beryllium self-diffusion in the deeply supercooled state of a Zr46.7Ti8.3Cu7.5Ni10Be27.5 alloy has been studied by radiotracer technique employing isotope Be7 combination with ion-beam sectioning. The temperature dependence diffusivity D is Arrhenius like D(T)=102.6 m2 s−1 exp(−2.6 eV/kBT). tracer diffusivities consistently extend size diffusion observed liquid this to smallest constituent, but are at variance previously published results chemical Be diffusion.

Biocompatible silica-based mesoporous materials, which present high surface areas combined with uniform distribution of nanopores, can be organized in functional nanopatterns for a number applications. However, silica is by essence an electrically insulating material precludes applications electro-chemical devices. The formation hybrid electroactive nanostructures thus expected to great interest the design biocompatible conducting materials such as bioelectrodes. Here we show that grow...