Microstructure And Electrical Properties Of Ni/NiO Core/shell Nanowires

One-dimensional core-shell nanostructures are the double-layer or multi-layer structures prepared by the tailoring and modification of original nanomaterials.Due to its special optical,electrical and catalytic characteristics,the one-dimensional core-shell nanostructures have a potential applications in semiconductor devices,biomedicine and environment engineering area and so on,as essential components in catalysis,chemical sensor,supercapacitor and resistive random access memory.Following the development of nanotechnology,especially,the one-dimensional core-shell nanostructures have attracted extensive attention from the synthesis to design.In our work,the structures of Ni/NiO core-shell nanowires?NWs?under the different annealing temperature have been characterized and analyzed.Also,the relationship between the microstructural and resistive switching of the single Ni/NiO nanowire device has been analyzed.In our work,the structures of Ni/NiO core-shell nanowires under the different annealing temperature have been characterized and analyzed.Also,the relationship between the microstructural and resistive switching of the single Ni/NiO core-shell nanowire device has been analyzed.First,the Ni/NiO core/shell nanowires?NWs?have been prepared by chemical reduction under assistance of magnetic fields and subsequent heat treatment.The surface morphology,microstructural and magnetic properties of Ni/NiO core-shell NWs under the different annealing temperature have been characterized and analyzed by the scanning electron microscopy,Raman spectra,x-ray diffraction,transmission electron microscope,and thermogravimetric analyzer and the oxidation process of Ni NWs was discussed.The single Ni/NiO core-shell-nanowire device was fabricated by the conventional CMOS process on SiO₂/Si substrate and the influence of annealing temperature on the resistance switching effect of device has been analyzed.These results showed that the surface of Ni/NiO NWs become smoother,the crystallinity of the NiO layer was improved,and the thickness of NiO layer increased with the annealing temperature increasing.Correspondingly,the magnetic properties of Ni/NiO NWs degraded.The I-V curves showed that the single Ni/NiO core-shell nanowire annealed at 300?has a great resistance switching behavior with a low switching threshold voltage and a high ON/OFF ratio.Unfortunately,electrical properties of Ni/NiO core-shell nanowire degraded with the annealing temperature increasing.It is possibly resulted from the thicker NiO layer and higher crystal quality of NiO,which prevented the formation of the conductive filaments in NiO layer.These results suggested that the Ni/NiO core-shell-nanowire will be have an optimized resistance switching effect after annealed at an optical temperature.