Corrosion product formed on zinc sample during 2 weeks immersion in saline solution has been investigated. The corrosion layer morphology as well as its chemical composition, was analyzed using scanning electron microscopy (SEM), x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Electrochemical measurement was used to analyze the corrosion behavior. Zinc oxide, zinc hydroxide and zinc hydroxide chloride were formed on zinc surface in saline solution. The thickness of corrosion layer increased with the time increased. The pure Zn has an estimated corrosion rate of 0.063 mm y−1 after immersion for 336 h. Probable mechanisms of zinc corrosion products formation are presented.

Flowerlike Ni−Fe alloy nanostructures composed of nanorods have been synthesized via a facile hydrothermal approach at relatively low temperature (100 °C) independent of surfactants or external magnetic field. The concentrations of NaOH and FeCl3 play a crucial role in determining the morphology of the Ni−Fe alloy via adjusting the reaction rate. The excessive amount of NaOH favors the formation of alloyed phase without segregation. Such flowerlike architectures follow a stepwise growth mechanism with initial formation of nanocores aggregated from nuclei and a subsequent site-specific anisotropic growth of nanorods along their easy magnetic axis under kinetic control. The Ni−Fe flowers showed enhancement of their ferromagnetic properties, which may be attributed to the anisotropic shape and the incorporation of Fe compared to pure Ni. Our work may shed light on the designed fabrication of complex 3D architectures of other alloyed materials.

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High pressure has been demonstrated to be a powerful approach of producing novel condensed-matter states, particularly in tuning the superconducting transition temperature (T c) of the superconductivity in a clean fashion without involving the complexity of chemical doping. However, the challenge of high-pressure experiment hinders further in-depth research for underlying mechanisms. Here, we have successfully synthesized continuous layer-controllable SnSe2 films on SrTiO3 substrate using molecular beam epitaxy. By means of scanning tunneling microscopy/spectroscopy (STM/S) and Raman spectroscopy, we found that the strong compressive strain is intrinsically built in few-layers films, with a largest equivalent pressure up to 23 GPa in the monolayer. Upon this, unusual 2 × 2 charge ordering is induced at the occupied states in the monolayer, accompanied by prominent decrease in the density of states (DOS) near the Fermi energy (E F), resembling the gap states of CDW reported in transition metal dichalcogenide (TMD) materials. Subsequently, the coexistence of charge ordering and the interfacial superconductivity is observed in bilayer films as a result of releasing the compressive strain. In conjunction with spatially resolved spectroscopic study and first-principles calculation, we find that the enhanced interfacial superconductivity with an estimated T c of 8.3 K is observed only in the 1 × 1 region. Such superconductivity can be ascribed to a combined effect of interfacial charge transfer and compressive strain, which leads to a considerable downshift of the conduction band minimum and an increase in the DOS at E F. Our results provide an attractive platform for further in-depth investigation of compression-induced charge ordering (monolayer) and the interplay between charge ordering and superconductivity (bilayer). Meanwhile, it has opened up a pathway to prepare strongly compressed two-dimensional materials by growing onto a SrTiO3 substrate, which is promising to induce superconductivity with a higher T c.

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