Nickel powders were obtained after chemical reduction of nickel chloride by KBH4 using absolute ethylenediamine as solvent in a stainless autoclave. The product was characterized by X-ray powder diffraction (XRD), sca...Nickel powders were obtained after chemical reduction of nickel chloride by KBH4 using absolute ethylenediamine as solvent in a stainless autoclave. The product was characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). XRD results show that the as-prepared sample have different crystal structures at different reaction temperatures. It was face-centered cubic (fcc) nickel under 200 ℃, and there was only hexagonal close-packed (hcp) Ni above 300 ℃. At 250 ℃, the patterns indicate that both fcc and hcp phases of Ni coexist in the as-prepared sample. When the ethylenediamine was respectively substituted by benzene and toluene, only fcc phase nickel was obtained. SEM and TEM indicate that the fcc Ni is nano-particles with about 100 nm in diameter, and hcp nickel is nano-crystalline clusters.展开更多
Nano-crystalline NiO was synthesized by combustion reaction between aqueous Ni（NO3）2 and Glycin at 500℃.The crystal structure,particle size and morphology of the products were examined by X-ray powder diffraction ...Nano-crystalline NiO was synthesized by combustion reaction between aqueous Ni（NO3）2 and Glycin at 500℃.The crystal structure,particle size and morphology of the products were examined by X-ray powder diffraction （XRD）and transmission electron microscope （TEM）.The results show that the NiO is face-centered cubic （fcc） crystal phase with average diameter of 10 nm.展开更多
文摘Nickel powders were obtained after chemical reduction of nickel chloride by KBH4 using absolute ethylenediamine as solvent in a stainless autoclave. The product was characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). XRD results show that the as-prepared sample have different crystal structures at different reaction temperatures. It was face-centered cubic (fcc) nickel under 200 ℃, and there was only hexagonal close-packed (hcp) Ni above 300 ℃. At 250 ℃, the patterns indicate that both fcc and hcp phases of Ni coexist in the as-prepared sample. When the ethylenediamine was respectively substituted by benzene and toluene, only fcc phase nickel was obtained. SEM and TEM indicate that the fcc Ni is nano-particles with about 100 nm in diameter, and hcp nickel is nano-crystalline clusters.
文摘Nano-crystalline NiO was synthesized by combustion reaction between aqueous Ni（NO3）2 and Glycin at 500℃.The crystal structure,particle size and morphology of the products were examined by X-ray powder diffraction （XRD）and transmission electron microscope （TEM）.The results show that the NiO is face-centered cubic （fcc） crystal phase with average diameter of 10 nm.
基金supported by theScience and Technology Project of Guangdong Prov-ince (2KM02304G)Qian Bai Shi Project of Guang-dong Province (Q02059)International Coopera-tion Project of Hubei Province (2006CA014)~~
