A combustion synthesized AlN powder was studied for its feasibility as a filler for epoxy molding compound (EMC) and effects of various experimental parameters on the thermal conductivity and moisture resistance of the EMC were investigated. The AlN powder was coated with silane both to increase the moisture resistance of the EMC and to enhance the bonding between the filler AlN and the matrix resin. The thermal conductivity could be significantly increased by using AlN powders with large particle sizes and this was considered to be due to a reduction in interface area between the AlN particles and the matrix resin. A thermal conductivity of 14 W/mK was obtained when the EMC was fabricated by a process involving no use of a solvent and a AlN powder with a particle size of 35.3 mm and a filler content of 67 vol % were used.

The crossbar structure of resistive random access memory (RRAM) is the most promising technology for the development of ultrahigh-density devices for future nonvolatile memory. However, only a few studies have focused on the switching phenomenon of crossbar RRAM in detail. The main purpose of this study is to understand the formation and disruption of the conductive filament occurring at the crossbar center by real-time transmission electron microscope observation. Core-shell Ni/NiO nanowires are utilized to form a cross-structure, which restrict the position of the conductive filament to the crosscenter. A significant morphological change can be observed near the crossbar center, which results from the out-diffusion and backfill of oxygen ions. Energy dispersive spectroscopy and electron energy loss spectroscopy demonstrate that the movement of the oxygen ions leads to the evolution of the conductive filament, followed by redox reactions. Moreover, the distinct reliability of the crossbar device is measured via ex situ experiments. In this work, the switching mechanism of the crossbar core-shell nanowire structure is beneficial to overcome the problem of nanoscale minimization. The experimental method shows high potential to fabricate high-density RRAM devices, which can be applied to 3D stacked package technology and neuromorphic computing systems.

In the present work, a new type of ecofriendly and recyclable magnetic hierarchical porous Cd2+ imprinted photocatalytic nanoreactors (MHP-Cd) are developed by utilizing the ion imprinting technique. Owing to numerous Cd2+ cavities generation and corresponding high adsorption capacity of Cd2+ of 154.99 mg/g in the imprinted layer, the as-prepared nanoreactors exhibit excellent selectivity of Cd2+ adsorption under corroboration of enhanced k ions of Cd2+ to other ions [k ions(Cd2+/Fe3+) = 2.836, k ions(Cd2+/Cu2+) = 2.303, and k ions(Cd2+/Zn2+) = 3.064]. Importantly, with coexistence of mesoporous and sodium pyrrolidone carboxylate, i.e., light transmittance materials, toxic tetracycline can easily contact with CdS and most of the light is amenable to being adsorbed by CdS, consequently promoting higher photocatalytic activity for degradation of tetracycline (i.e., degradation rate reaches 75.32%). Such developed MHP-Cd photocatalysts demonstrate a highly selective adsorption of Cd2+ and simultaneous tetracycline degradation with effective inhibition of the secondary pollution. With a promoted stability for recycling, our work provides a new promising technique for environment-friendly selective adsorption of targeted heavy metal ions and synchronous degradation of antibiotic containment in mixed water environments.

The fabrication and placement of high purity nanometals, such as one-dimensional copper (Cu) nanowires, for interconnection in integrated devices have been among the most important technological developments in recent years. Structural stability and oxidation prevention have been the key issues, and the defect control in Cu nanowire growth has been found to be important. Here, we report the synthesis of defect-free single-crystalline Cu nanowires by controlling the surface-assisted heterogeneous nucleation of Cu atomic layering on the graphite-like loop of an amorphous carbon (a-C) lacey film surface. Without a metal-catalyst or induced defects, the high quality Cu nanowires formed with high aspect ratio and high growth rate of 578 nm/s. The dynamic study of the growth of heterogeneous nanowires was conducted in situ with a high-resolution transmission electron microscope. The study illuminates the new mechanism by heterogeneous nucleation control and laying the groundwork for better understanding of heterosurface-assisted nucleation of defect-free Cu nanowire on a-C lacey film.

Fig. 1. Study flow diagram. Selection of studies included in the present systematic review and meta-analysis.