【摘要】 以纯锌粉作为原料,用气相输运法在650℃合成了ZnO双晶纳米梳结构,并用高分辨透射电镜及选区电子衍射等方法对其微观结构进行了研究.结果表明双晶纳米梳两侧的齿针呈一定角度以孪晶方式对称生长,其孪晶面为(11-3),两侧齿针都垂直于孪晶界,其直径均匀分布在50—100nm,每一侧梳背和齿针的生长方向均分别为〈01-10〉和〈0001〉.由于孪晶造成了晶体取向的变化,基于镜像对称的特征,ZnO双晶纳米梳两侧梳背的外缘可以均为Zn终结的(0001)面,因此都可以发生自催化作用并形成分支结构,这种纳米结构的生长过程与王中林等人提出的极性生长机理相符合.更多还原

【Abstract】 Bicrystalline ZnO nanocombs have been prepared by zinc powder evaporation process at 650℃. The structure of bicrystalline ZnO nanocombs was characterized by XRD, HTEM, SAD, etc., which indicate that the as-synthesized sample are composed of two crystals that form a twin structure parallel to the (1 1 3) plane with the growth direction of the branching nanowires and the main stems closely parallel to〈0 0 0 1〉 and〈0 1 1 0〉,respectively. Due to the unique twin structures, both sides of the main stems could be Zn-terminated ZnO (0 0 0 1) polar surfaces, which are chemically active. Therefore the aligned branching nanowires can be grown from both sides of the main stems, which is consistent with the structure of the bicrystalline nanomaterials we have obtained. The growth of bicrystalline ZnO nanocombs bears direct evidence to the polar-surface dominated growth mechanism of the ZnO nanomaterials.更多还原