A new technique called energy-loss magnetic chiral dichroism (EMCD) has recently been developed [P. Schattschneider, et al. Nature441, 486 (2006)] to measure magnetic circular dichroism in the transmission electron microscope (TEM) with a spatial resolution of 10 nm. This novel technique is the TEM counterpart of x-ray magnetic circular dichroism, which is widely used for the characterization of magnetic materials with synchrotron radiation. In this paper we describe several experimental methods that can be used to measure the EMCD signal [P. Schattschneider, et al. Nature441, 486 (2006); C. Hébert, et al. Ultramicroscopy108(3), 277 (2008); B. Warot-Fonrose, et al. Ultramicroscopy108(5), 393 (2008); L. Calmels, et al. Phys. Rev. B76, 060409 (2007); P. van Aken, et al. Microsc. Microanal.13(3), 426 (2007)] and give a review of the recent improvements of this new investigation tool. The dependence of the EMCD on several experimental conditions (such as thickness, relative orientation of beam and sample, collection and convergence angle) is investigated in the transition metals iron, cobalt, and nickel. Different scattering geometries are illustrated; their advantages and disadvantages are detailed, together with current limitations. The next realistic perspectives of this technique consist of measuring atomic specific magnetic moments, using suitable spin and orbital sum rules, [L. Calmels, et al. Phys. Rev. B76, 060409 (2007); J. Rusz, et al. Phys. Rev. B76, 060408 (2007)] with a resolution down to 2 to 3 nm.

The mechanical properties of Zr52.5Ni14.6Al10Cu17.9Ti5 and Ti40Zr25Ni3Cu12Be20 metallic glasses were investigated under uniaxial compressive loading and small punch loading, respectively. The Zr-based metallic glass displays higher density of shear bands, larger critical shear offsets and higher energy absorbing capability than the Ti-based metallic glass under the small punch tests. A concept of critical shear offset is proposed to explain the difference in shear deformation abilities or plasticity of different metallic glasses. The current experiments demonstrate that, in contrast with the small difference between the responses of the Zr- and Ti-based metallic glasses under uniaxial compressive loading, the biaxial tension produced by the small punch test is an effective way to evaluate the difference in shear deformation abilities and can be used to distinguish the brittleness or plasticity of various metallic glasses.

Laser Engineered Net Shaping (LENS™) is a laser-assisted manufacturing process that offers the possibility of producing metallic coatings and components with highly nonequilibrium microstructures. In this work, the microstructure developed by LENS deposition of Cu47Ti33Zr11Ni8Si1 powder on a bulk metallic glass substrate, with nominal composition Zr58.5Nb2.8Cu15.6Ni12.8Al10.3, is investigated. Single-layer deposition results in the formation of an inhomogeneous but partially amorphous layer above a crystalline heat-affected zone. Elemental analysis of the deposited layer indicates incomplete mixing of the powder with the melt pool. The as-deposited alloy exhibits a single glass transition event and its primary crystallization event is consistent with the first crystallization temperature of the Cu-based powder. Subsequent remelting of this layer results in a still partially amorphous deposit with a uniform composition of (Zr + Nb)51.8Cu24.7Ti3.4Ni16.4Al3.7. The remelted layer exhibits a structural rearrangement immediately prior to the primary crystallization event, possibly associated with the formation of a quasicrystalline phase.

Artificially engineered metamaterials have emerged with properties and functionalities previously unattainable in natural materials. The scientific breakthroughs made in this new class of electromagnetic materials are closely linked with progress in developing physics-driven design and novel parallel fabrication methods. For example, a smooth superlens has been demonstrated with 30-nm imaging resolution, or 1/12 of the corresponding wavelength, far below the diffraction limit. Similarly, a photoswitchable optical negative-index material has been printed, showing a remarkable tuning range of refractive index in the communication wavelength. New frontiers are being explored as intrinsic limitations challenge the scaling of microwave metamaterial designs to optical frequencies. These novel metamaterials promise an entire new generation of passive and active optical elements, such as paper-thin superlenses and modulators.

In this study, the effects of electromigration (EM) on the growth of Cu–Sn intermetallic compounds (IMCs) in Cu/SnBi/Cu solder joints under 5 × 103 A/cm2 direct current stressing at 308, 328, and 348 K were investigated. For each Cu/SnBi/Cu solder joint under current stressing, the IMCs at the cathode side grew faster than that at the anode side. The growth of these IMCs at the anode side and the cathode side were enhanced by electric current. The growth of these IMCs at the cathode followed a parabolic growth law. The kinetics parameters of the growth of the IMCs were calculated from the thickness data of the IMCs at the cathode side at different ambient temperatures. The calculated intrinsic diffusivity (D0) of the Cu–Sn IMCs was 9.91 × 10−5 m2/s, and the activation energy of the growth of the total Cu–Sn IMC layer was 89.2 kJ/mol (0.92 eV).

Fe-doped In2O3 nanocubes were synthesized by a solvothermal method. The lattice constant a decreases linearly as Fe doping concentration increases, and Raman scattering measurement proves the incorporation of Fe ions into the In2O3 crystal lattice. Mössbauer spectra show the presence of mixed valence of Fe ions instead of Fe3O4, while the sample is superparamagnetic. The products with an average diameter of 80 nm have a single-crystalline phase and appear as a square shape. Magnetic measurements confirm the superparamagnetic properties of the nanocubes, and electron paramagnetic resonance studies indicate Fe ions occupy different sites in the In2O3 matrix.

A facile one-pot synthetic approach, using oleic acid and oleylamine as composite stabilizers combined with high-temperature treatment in 1-octadecene, has been developed for the preparation of monodisperse and uniform lanthanum phosphate and europium-doped lanthanum phosphate nanocrystals. In particular, with the present synthetic approach, the size of the resulting nanocrystals could be tuned precisely and continuously from 3.5 to 6.5 nm by seed-mediated epitaxial growth. The as-obtained uniform nanocrystals with hydrophobic surfaces, which show efficient photoluminescence, could be easily dispersed in nonpolar solvents. More importantly, these nanocrystals can also be easily modified to water-dispersed ones with hydrophilic surfaces for potential use in in vitro imaging in bioanalysis. In addition, a synthetic mechanism for these monodisperse nanocrystals is presented and discussed.

The thermodynamic and kinetic fragilities of two near-eutectic Mg-based bulk metallic glass (BMG)-forming liquids, Mg61Cu28Gd11 and Mg59.5Cu22.9Ag6.6Gd11, were investigated using high-precision differential scanning calorimeter (DSC). The thermodynamic fragility denoted as F3/4 was determined by evaluating the temperature dependence of the excess entropy Sex. The heating rate dependence of the relaxation time at the glass transition temperature was investigated to measure the kinetic fragility. A positive correlation between the thermodynamic and kinetic fragilities could be established in Mg-based BMG-forming liquids on the basis of Adam-Gibbs equation in contrast to a number of other BMGs.

Ni–7 wt% V diffusion barrier is commonly used in flip chip technology, and Sn is the primary element of all commercial electronic solders. Different from the interfacial reactions in the Sn/Ni couples, a ternary T phase is formed in the Sn/Ni–7 wt% V couples reacted at temperatures lower than 350 °C. The T phase is a mixture of an amorphous phase and the Ni3Sn4 phase with grains about 50 nm in size. The amorphous phase is composed mainly of Sn and V atoms, and it is formed due to the fast diffusion of Sn and relative immobility of V. Activation energy of the T phase formation is 16.5 kJ/mol, which is approximately 50% of that of the Ni3Sn4 phase determined from the Sn/Ni interfacial reactions. The T phase is no longer formed and the reaction product is the Ni3Sn4 phase in the Sn/Ni–7 wt% V couples reacted at temperatures higher than 350 °C.

A crystalline silicon surface, loaded by a Berkovich indenter to a constant maximum load, was unloaded using three unload functions, each consisting of five linear segments of equal time period. The first function had an exponentially decaying unload rate and was found to promote a pop-out event more readily than the second function, having a linear unload rate, or the third case with its unload rate increasing with time. Statistical analyses of experimental data suggest that the unload rate within 20%–30% of the maximum load, when the mean contact pressure in the indent volume is roughly 5 to 6 GPa, is the most dominant factor influencing the probabilistic occurrence of a pop-out event. Unload rates at higher load levels were shown to have a much less significant effect on the probability of pop-out occurrence.