ZnO双晶纳米梳

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(1 1-3)，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〈0 1-1 0〉和〈0 0 0 1〉.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(0 0 0 1)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.关键词：氧化锌纳米梳双晶极性生长

Bicrystalline zinc oxide nanocombs

Bicrystalline ZnO nanocombs have been prepared by zinc powder evaporation proces s at 650℃. The structure of bicrystalline ZnO nanocombs was characterized by XR D, 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 th e growth direction of the branching nanowires and the main stems closely paralle l 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 surface s, 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 bicrystallin e ZnO nanocombs bears direct evidence to the polar-surface dominated growth mech anism of the ZnO nanomaterials.