直接氮化法制备氮化铝纳米线

Synthesis of AlN Nanowires Via a Direct Nitridation Method

在氮、氢混合气气流中(氢气10%,体积比),以铝和氯化铵混合粉体为原料,在水平管式炉中采用直接氮化法合成了氮化铝纳米线。使用扫描电子显微镜(SEM)、X射线衍射仪(XRD)和透射电子显微镜(TEM)对纳米线的形貌和结构进行了检测与分析;研究了铝和氯化铵的比例(质量比)、反应温度、升温速度等因素对生成物的种类、形貌和氮化铝纳米线产量的影响。研究发现,所获得的AlN纳米线为单晶六方纤锌矿结构,表面不光滑且有非晶层,而AlN纳米线依照Vapor-Solid(VS,气-固)生长机制生长。获得了较为优化的制备氮化铝纳米线的工艺条件,利用VS生长机制和气相过饱和度概念对上述影响氮化铝纳米线生长的条件进行了初步的机理分析。

AlN nanowires were synthesized by direct nitridation with Al-NH_4Cl as starting mixture.The nitridation experiments were carried out in a horizontal tube furnace and in a N_2 and H_2 mixture gas flow（10 vol% H_2）.The AlN nanowires were investigated using X-ray diffractometry（XRD）,scan electron microscopy（SEM）,high resolution transmission electron microscopy（HREM）.The effects of temperature,temperature rising rate and ratio of Al-NH_4Cl（wt%） on the types and morphologies of the products and the yields of the AlN nanowires were studied.The results indicate that the synthesized AlN nanowire has hexagonal single crystal structure covered with a thin amorphous layer and the growth of the AlN nanowires is based on a vapor-solid（VS） mechanism.The optimized synthesis factors of the AlN nanowires have been obtained and the effects of the above factors on the growth of the AlN nanowires are primarily analyzed using the VS growth mechanism and the concept of the vapor supersaturation degree.