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Ni and Co metallic microparticles with submicron size were synthesized with a simple wet chemical reduction method at a relatively low temperature. Then their morphologies and structures were characterized by SEM and XRD. Ni metallic microparticles have spherical-shape morphology with fcc crystalline structure, however, Co has a distinct leaf-like morphology with the fcc and hcp mixed phases crystalline structures. For the characterization of their electromagnetic properties, paraffin matrix composites containing different molar ratio Ni and Co mixture powder as fillers were prepared. It was found that both the electromagnetic properties and electromagnetic microwave absorption performances of absorber layer were remarkably influenced by Ni/Co molar ratio. The electromagnetic microwave absorption performances were significantly improved by blending Ni and Co metallic microparticles into paraffin matrix with changing Ni/Co molar ratio, and enhanced mechanism were discussed.

In this letter, we report that a new bulk metallic glass (BMG) of Ti 20 Zr 20 Cu 20 Ni 20 Be 20 , with a critical diameter of 3 mm, has been successfully fabricated using copper mold casting method. Different from most reported BMGs which possess one or two main constituents, this newly developed BMG possesses five elements with equal atomic concentration, which has been defined as high entropy alloy. This high entropy bulk metallic glass (HE-BMG) exhibits high fracture strength of 2315 MPa but a brittle behavior. The glass forming ability, mechanical property and phase transformation after annealing of the HE-BMG are discussed in detail. And a way for designing high entropy bulk glassy alloy has been proposed.

The strategy to manipulate nanoscale building blocks into well-organized hierarchical architectures is very important to both material synthesis and nanodevice applications. In this work, hierarchical ZnO nanostructures with controllable morphology were synthesized by a two-step chemical route. At step-one, hexagonal- and spherical-shaped ZnO nanostructures were deposited on glass slide substrates. At step two, the morphology of hierarchical ZnO nanostructures could be effectively controlled by changing the composition of solutions. The method described here is a simple and reproducible process, which does not require any templates, catalysts, or surfactants, but can control the morphology of ZnO crystals from simple to complex. The morphologies and structures of the products were characterized by field-emission scanning electron microscopy and X-ray diffraction measurements. Room-temperature photoluminescence spectra demonstrate that the variety of nanostructures can cause the variation of the photoluminescence intensity, suggesting that the controlled morphologies can be used to modulate the optical properties of ZnO nanostructures.