Mingwei Chen

TL;DR: The evolution of nanoscale structural heterogeneity in a metallic glass during β-relaxation is reported by utilizing amplitude-modulation dynamic atomic force microscopy and provides direct evidence on the structural origins of β- Relaxation in metallic glasses.

Abstract: A quasicrystalline phase was discovered in a Zr65Al7.5Ni10Cu12.5Ag5 bulk metallic glass annealed in the supercooled liquid range. Through systematical transmission electron microscopy rotation analyses, the selected area electron diffraction patterns are obtained corresponding to fivefold, threefold, and twofold rotational symmetry, demonstrating that the precipitated phase is an icosahedral quasicrystalline phase with good rotational symmetry. It is concluded that the addition of Ag in the Zr-based metallic glass promotes the formation of the quasicrystalline phase. The present experimental result implies that there is a natural relationship between the Zr-based bulk metallic glasses and icosahedral quasicrystalline.

TL;DR: Freestanding nanoporous N-doped graphene with encapsulated RuO2 nanoparticles is developed as a cathode for rechargeable Li-O2 batteries, and the stabilized metal oxide catalyst reduces charge overpotentials enabling high-efficiency rechargeables with a long cycling lifetime.