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In this paper, copper coated carbon nanotubes (CNTs) was synthesized by decomposition of Cu(II) acetylacetonate (Cu(acac)2) in hydrogen atmosphere at 300 °C. The thickness of the copper coating was in nanoscale according to scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images, and Raman spectra indicated that certain intermediate bonds were formed between copper and the template CNTs. The crystalline structure of copper and its growth orientation were determined by X-ray diffraction (XRD) and selected area electron diffraction (SAED). The copper coating on CNTs had a face-centered cubic structure and its growth orientation was parallel to $$ (\bar 111) $$ planes. The method developed in this paper had the advantages of simplicity in both process control and experiment equipments, so that it might provide a possibility of large-scale production. [ABSTRACT FROM AUTHOR]

Gd3+ was chosen as a substitute for Bi3+ in BiNbO4 ceramics, and the substitution effects on the sintering performance and microwave dielectric properties were studied in this paper. The high temperature triclinic phase was observed only in the Bi0.98Gd0.02NbO4 ceramics when sintered at 920 °C. Both bulk densities and dielectric constant (εr) increased with the sintering temperature, while decreased with the Gd content. The quality factor ( Q) exhibited a correlation to the Gd content and the microstructures of Bi1− x Gd x NbO4 ceramics. At the sintering temperature of 900 °C, Bi0.992Gd0.008NbO4 ceramics exhibited microwave dielectric properties of εr ∼ 43.87, Q × f ∼ 16,852 GHz (at 4.3 GHz), and its temperature coefficient of resonant frequency (τf) was found to be near-to-zero. [ABSTRACT FROM AUTHOR]

In this work, the effect of copper through-silicon via (TSV) interconnect diameter on stress buildup in Cu TSVs was experimentally determined using a synchrotron-based X-ray microdiffraction technique. A single chip with different Cu TSV diameters (3, 5, and 8 µm), all having the same depth and processing conditions was studied. Prior to the measurements, the chip was annealed at 420 °C (30 min), leading to microstructurally stable Cu TSVs. The mean measured hydrostatic stresses were (190 ± 25) MPa (3 µm diameter), (138 ± 19) MPa (5 µm diameter), and (209 ± 26) MPa (8 µm diameter), respectively. No clear relationship between the measured stress and Cu TSV diameter was observed. This trend is attributed to the operation of stress relaxation mechanisms in the polycrystalline Cu TSVs, which includes plastic deformation, grain boundary sliding, void formation/growth, and rate-controlled dislocation motion, which are often neglected in reported finite element analysis studies. Additionally, this study highlights that the thermo-mechanical behavior of Cu TSVs is significantly influenced by their thermal history. [ABSTRACT FROM AUTHOR]

Cu–Ag bimetallic nanoparticles with atomic ratio of 2.1:1 and diameter in the range of 15–30 nm were decorated on acid-treated multi-walled carbon nanotubes by a chemical reduction method, which was characterized by transmission electron microscope (TEM), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTEM). The Cu–Ag/MWNTs nanocomposites were used to construct a modified electrode toward biosensing of H2O2 with a high sensitivity. The catalytic ability of MWNTs/Cu–Ag toward H2O2 was much better than that of MWNTs/Cu and MWNTs/Ag, which indicated that there is a cooperation effect between Cu and Ag. [ABSTRACT FROM AUTHOR]

Single layers of Cu and In were deposited onto Mo coated glass substrates by radio frequency sputtering. The Cu11In9 phase has been found to be the majority phase in these precursors. The selenization of the sputtered layers has been achieved by depositing a 1 μm Se layer onto the precursor by thermal evaporation followed by an annealing in vacuum. Samples were annealed at different temperatures varying between 100–600°C at intervals of 50°C. The chalcopyrite structured ternary phase of CuInSe2 with a significant amount of preferential orientation in the (112) direction was obtained in samples annealed at 400°C or above. Morphological, compositional and structural analyses of the samples annealed at different temperatures were performed using a variety of complementary techniques. The results were analysed to explain the growth of CuInSe2 on the selenization of sputtered Cu-In precursors. The occurrence of various binary phases of Cu-In, Cu-Se and In-Se in different annealing temperature ranges has also been investigated. The phenomenon of volume expansion in CuInSe2 on selenization has been found to manifest itself as a shift in the characteristic (110) X-ray diffraction peak of Mo. [ABSTRACT FROM AUTHOR]

Focuses on the in situ combustion synthesis of ultrafine TiB2 particles reinforced Cu matrix composite. Discussion of the microstructure of Cu matrix; Presentation of the X-ray diffraction patterns of the synthesized Cu-TiB2 composite.

Cuprous oxide (Cu2O) nano- and microstructures possess unique properties that may find a variety of applications. Environmentally benign synthesis of Cu2O with well-controlled morphology is highly desirable. In this study, Cu2O crystals with tunable shapes are synthesized using cellulose nanofibrils (CNFs) as a shape regulator and the sole reducing agent in aqueous environment. By simply increasing Cu2O precursor concentration, the Cu2O crystals evolved from octahedra to cuboctahedra, and finally cubes, accompanied with increasing size from nano- to microscale. The selection of Cu chelating agent (sodium tartrate or potassium sodium tartrate) affected the crystal growth rate. Transition in the relative intensities of the (111) and the (200) crystalline peaks in their XRD patterns was consistent with the morphology change. During the growth of crystals, CNFs were preferably bound to the {111} crystalline facet. The introduction of KBr to the reaction system produced short hexapods. The resultant CNF-Cu2O hybrids were incorporated into waterborne polyurethane (WPU) films. Even with 0.5 wt% CNF-Cu2O, the WPU film showed significant enhancement in modulus, strength and elongation at break. This work proves the possibility of controlled growth of Cu2O particles aided by CNFs and provides a new strategy for improving the performance of eco-friendly WPU films. [ABSTRACT FROM AUTHOR]