一些低维材料的微观结构(一)——超细羰基铁粉和SiCB激光制粉

THE MICROSTRUCTURE OF SOME LOW DIMENSIONAL MATERIALS(1)——Ultrafine Carbonyl Iron Powders and Laser-made SiCB Powders

利用电子能量损失谱、微衍射及高分辨电子显微术等方法观察和分析了直径为5—30nm的超细羰基铁粉和直径为30—80nm 的 SiCB 超细粉。超细铁粉主要由中心核α-Fe 和外壳 Fe_3O_4组成,其中部分超细粉完全被氧化,形成空心的γ-Fe_2O_3。激光制得的 SiCB 超细粉由 Si,SiC,SiB_6多相复合微粒组成,并有大量孪晶形成。

The carbonyl iron ultrafine powders(UFCIP)of the size ranging from 5 to30nm and the laser-made SiCB ultrafine powders of the size ranging from 30 to 80nmwere characterized by CTEM,EELS,HREM and microdiffraction.It was found that thecarbonyl iron ultrafine powders are composed of the particles of α-Fe enclosed in about6nm thick skin of polycrystalline Fe_3O_4,some of the particles being completely oxidized in-to polycrystalline γ-Fe_2O_3 with the grains of 5-10nm in size,which form about 6nm thickshell with a hollow core in the center.The SiCB ultrafine powders are composed of Si,SiCand SiB_6 with most of the particles being twinned.