Expanded graphite/cobalt ferrite/polyaniline (EG/CF/PANI) ternary composites were obtained by a two-step process. The intercalation compound, CF embedded in EG, was synthesized by a coprecipitation method. PANI could then be coated on the surface of the EG/CF microparticles by in-situ polymerization to form ternary composites of EG/CF/PANI. The results indicate that the electrical and magnetic performance of EG/CF and EG/CF/PANI composites are related to their composition. The EG/CF composite with mass ratio of 1.0 has the maximal conductivity (833.33 S·cm−1) among the binary composites. Saturation magnetizations (Ms) of the EG/CF composite with mEG/mCF of 0.8 is the largest among EG/CF composites, the ternary composites of EG/CF/PANI were prepared from the EG/CF composite at this mass ratio. The electromagnetic wave absorbing property of all ternary composites excelled those of EG/CF composites, and the sample with 40 wt% of PANI has the best absorption properties in the range of 8–18 GHz frequency.

The metal nanoparticles dispersed in matrices of composite material are able to apply in different technologies based on their peculiarity. This article reports the preparation of Ag/epoxy nanocomposite film with aligned Ag nanowires coated on glass substrate by multistep processing including synthesis of Ag nanowires by seed-mediated method, dispersion of Ag nanowires in the epoxy resin, and stretching to form the Ag/epoxy nanocomposite film. The results showed that Ag nanowires had been well aligned in the direction of stretching, both in the surface layer and in the internal of the film. Meanwhile, the Ag/epoxy nanocomposite film showed an obviously infrared polarization property in a broad wavelength range from 1600 to 2600 nm, with transmittance over 70%. The mechanisms for the orientation of Ag nanowires and the generation of polarization property of the films were discussed, respectively.

In this work, antimony trioxide (Sb2O3) has been doped into MgB2 samples to act as an additive. The doping level varies from 2.5 to 15 wt%. The effects of Sb2O3 addition on the lattice parameters, critical temperature (Tc), critical current density (Jc), and upper critical field (Hc2) have been investigated in detail. It has been found that Sb2O3 doping results in a small depression in Tc. The Jc value is 2.4 × 103 A·cm−2 for the 2.5% Sb2O3-doped sample at 5 K and 8 T, which is more than two times higher than for the undoped sample. The significant Jc improvement at high fields is attributed to the Hc2 enhancement caused by the increased disorder.

Magnetoelectric (ME) effect has been studied in bi-rectangular structure made up of epoxy-bonded negative/positive magnetostrictive and piezoelectric flakes. The ME effect is affected by negative and positive magnetostrictive flakes. The ME voltage coefficient at resonance frequency shows a nearly constant plateau behavior with the bias magnetic field increased from 1 to 3.5 kOe. There is no interface between magnetostrictive and piezoelectric flakes required to achieve ME coupling, which provides a new choice to make ME devices.

Bismuth sulfide (Bi2S3) polycrystalline bulks with a high relative density (>90%) were fabricated by combining mechanical alloying (MA) and spark plasma sintering (SPS). The microstructural and thermoelectric (TE) properties were investigated with a special emphasis on the influence of SPS temperature. The components (Bi/S ratio), grain size, and relative density of Bi2S3 bulk are sensitive to the SPS temperature, which all affect the electrical transport properties of samples. Elevating SPS temperature results in grain growth, densification, and spontaneous texturing, which benefit to enhance TE properties, whereas overheating leads to severe volatilization of both S and Bi and formation of porous microstructure. The highest figure of merit value reaches 0.22 at 573 K for the Bi2S3 sample obtained by applying SPS at 673 K for 5 min, which is the maximum value reported so far in bulk Bi2S3 system. The enhanced TE property of cheap and environmental friendly Bi2S3 material indicates a great promise in TE devices.

Core–shell structured Sn/carbon nanotube (CNT) was prepared by one-pot chemical vapor deposition (CVD) method in N2/C2H2 (10% C2H2) using nanosized SnO2 as the starting material. The obtained one-dimensional material is composed of a disordered carbon shell and a single-crystalline Sn nanorod core. The diameter of the Sn nanorod and the thickness of the carbon shell are around 40–50 and 4–5 nm, respectively, when the CVD reaction was carried out at 650 °C for 2 h. The core–shell structured Sn/CNT exhibits improved electrochemical performance compared with bare Sn with a diameter of around 100 nm. A reversible capacity of around 350 mAh/g can be retained after 20 cycles at 50 mA/g for Sn/CNT, while for bare Sn, the capacity drops rapidly to 100 mAh/g after the same cycles.

The catalytic influence of Ni, Zr2Ni5, and LaNi5 on the dehydrogenation properties of milled MgH2 was investigated. MgH2 milled in the presence of Ni (5 wt%) and Zr2Ni5 (5 wt%) catalysts for 2 h showed apparent activation energies, EA, of 81 and 79 kJ/mol, respectively, corresponding to ∼50% decrease in EA and a moderate decrease (∼100 °C) in the decomposition temperature (Tdec). A further 27 °C decrease in Tdec was observed after milling with 10 wt%Ni. Based on the EA values, the catalytic activity decreased in the following order: Ni ≈ Zr2Ni5 > LaNi5. X-ray photoelectron spectroscopy analysis of the milled and dehydrogenated states of the hydrides modified with Ni catalyst revealed that the observed reduction in EA may be due to the ability of Ni catalyst to decrease the amount of oxygen atoms in defective positions that are capable of blocking catalytically active sites thereby enhancing the dehydrogenation kinetics. In particular, our results reveal a strong correlation between the type of oxygen species adsorbed on Ni-modified MgH2 and the EA of the dehydrogenation reaction.

Diffusion of interstitial hydrogen atoms in α-iron was investigated using molecular dynamic simulation. In particular, hydrogen diffusivities in bulk, on (001) surface and within a Σ5 [100]/(013) symmetric tilt grain boundary (STGB) were estimated in a temperature range of 400 and 700 K. Furthermore, hydrogen diffusivities in a series of Σ5 [100] tilt grain boundaries with different inclinations were also determined as a function of temperature. The inclination dependence of activation energy for diffusion exhibits two local maxima, which correspond to two STGBs. Additional calculation of inclination dependence of boundary energy and boundary specific excess volume shows two local minima at the same STGBs. This suggests hydrogen diffusion into and within a grain boundary might be assisted by grain boundary excess volume and stress. Simulation of effects of hydrostatic pressure on diffusion shows tensile stress can promote hydrogen diffusion in lattice into grain boundary or surface traps, while compressive stress leads to a decrease in diffusivity, and a slower rate of filling these traps.

The direct integration of Ge nanowires with silicon is of interest in multiple applications. In this work, we describe the growth of high-quality, vertically oriented Ge nanowires on Si (111) substrates utilizing a completely sub-Au–Si-eutectic annealing and growth procedure. With all other conditions remaining identical, annealing below the Au–Si eutectic results in successful heteroepitaxial nucleation and growth of Ge nanowires on Si substrate while annealing above the Au–Si eutectic leads to randomly oriented growth. A model is presented to elucidate the effect of the annealing temperature, in which we hypothesized that sub-Au–Si-eutectic annealing leads to the formation of a single and well-oriented interface, essential to template heteroepitaxial nucleation. These results are critically dependent on substrate preparation and lead to the creation of integrated nanowire systems with a low thermal budget process.

Bamboo is a typical natural fiber-reinforced composite material with superior mechanical properties. As the reinforce phase in bamboo composite, the vascular bundles were extracted from different height locations of a Moso bamboo with an alkali treatment method, and the mechanical properties were investigated via the tensile test. It is found that both the longitudinal Young’s modulus and strength of the vascular bundles are linearly increased from the inner to outer side. To study the variation of mechanical properties of bamboo culm along the radial direction, thin bamboo slices were also tested. Using a modified rule of mixtures, the longitudinal Young’s modulus of bamboo slices are analyzed and excellent agreement can be found between experimental and theoretical results, which indicates that the longitudinal Young’s modulus of bamboo culm is cubically increased in the radial direction.

This article investigates the effect of grain structure on electromigration (EM) reliability of dual-damascene Cu interconnects with a CoWP capping layer, including the lifetime and statistics. Downstream EM tests were performed on two sets of CoWP-capped Cu interconnects with different grain sizes. Compared to Cu interconnects with the standard SiCN cap layer, the CoWP capping clearly improved the EM lifetime by ∼24× for the small grain structure and by another ∼14× for the large grain structure. Here, the effect of grain structure on EM lifetime was attributed to the grain boundary contribution to mass transport. The lifetime improvement, however, was accompanied with an increase in the statistical deviation, increasing from 0.27 for the SiCN cap to 0.53 for the small grain structure and to 0.88 for the large grain structure with the CoWP cap. This was attributed to the effect of grain structure in changing the statistical distribution of flux divergence sites and thus the failure statistics.

Copper/diamond-like carbon (DLC) was fabricated using pulsed laser deposition, and the effects of copper on the properties of DLC composites were studied. Experimental results showed that the presence of copper promoted surface evolution through the formation of nanoclusters, accentuated the formation of Si–C but graphitized the diamond bondings of DLC matrix. By considering the interaction of laser with copper/carbon composite target, the presence of copper may have increased the energy absorbed during laser deposition, as envisaged by Saha’s equation. Thus, upon the impingement of ions on substrate during deposition, the carbon and silicon atoms may have been redistributed to form Si–C bonding while the excess energy was released as heat to promote the formation of nanoclusters but graphitize the sp3 bonding in DLC. Although sp3 bonding was reduced with the presence of copper, mechanical characterization showed that the adhesion strength of the composite films was approximately five times higher compared to undoped DLC, as a result of the decrease in internal stress and the formation of Si–C bondings in DLC.

ReB2 was recently reported to exhibit high hardness and low compressibility, which both are strong functions of its stoichiometry, namely Re to B ratio. Most of the techniques used for ReB2 synthesis reported 1:2.5 Re to B ratio because of the loss of the B during high temperature synthesis. However, as a result of B excess, the amorphous boron, located along the grain boundaries of polycrystalline ReB2, would degrade the ReB2 properties. Therefore, techniques which could allow synthesizing the stoichiometric ReB2 preferably at room temperature are in high demand. Here, we report synthesis of ReB2 powders using mechanochemical route by milling elemental crystalline Re and amorphous B powders in the SPEX 8000 high-energy ball mill for 80 h. The formation of boron and perrhenic acids are also reported after ReB2 powder was exposed to the moist air environment for a 12-month period of time.

We study the one-pot facile hydrothermal growth of ultralong silver–carbon (Ag–C) nanocables with Ag nanowires as the cores and carbon as the sheaths through the mediation of H2SO4 and without using an organic surfactant. In the investigation, Ag–C nanostructures were systematically and extensively examined as a function of both temperature and H2SO4 concentration to locate the optimal conditions for preparing ultralong, robust, and uniform Ag–C coaxial nanocables at T = 180 °C and 0.5 M H2SO4. The characterization clearly demonstrated a simple, efficient, and surfactant-free synthesis of Ag–C nanocables. In the hydrothermal process, glycerol acts as both reducing agent and carbon source, while H2SO4 mediates the directional growth of the silver nanowire core and assists the deposition of carbon. Moreover, the nanocables manifest unusual ferromagnetism at room temperature and a plausible mechanism of forming Ag–C nanocables was proposed as a result of the chain-like hydrogen sulfate compounds owing to the H2SO4 mediation.