为提高气相传输法制备微纳结构样品形貌的可控性,进行了生长温度调控下氧化锌晶体生长机制及其变化的实验研究。实验中的样品制备,以高纯度锌粉末为原料,在无模板、无催化条件下,通过加热蒸发-氧化冷却-生长晶体过程实现。其中,蒸发温度固定于750℃,反应区气体氛围保持稳定,生长区温度在450-600℃变化,制备出不同生长温度下样品。对所制备出诸样品,应用扫描电子显微镜、X-射线衍射仪和透射电子显微镜等方法,进行形貌与结构表征。基于表征结果,观察、分析、研究生长温度变化的影响,结合理论分析,得出了生长温度通过对生长过程中锌蒸汽过饱和度的影响,决定着不同生长机制,从而有着不同的形貌结构的样品。
For the effective morphology-controlled fabrication of nanostructure znic oxide samples, experimental investigation on how the variation of temperature in growth region influences the growing mechanism of samples, which was fabricated by vapor-phase transport(VPT) method, was presented. All the samples were prepared by using znic powder with high purity as raw materials through the process of vaporized -oxided - cooled - growing and under the condition of template-free, catalyst-free, fixed heating temperature at 750 and stable gas reaction circumstances while the temperature in growth region was controlled to varied from 450-600 ℃. The morphology of the products was examined by scanning electron microscopy (SEM) , and their crystal structures were characterized by X-ray diffraction ( XRD) , high-resolution transmission electron microscopy ( HRTEM). Then two paradoxical experimental phenomena were observed based on the experimental data. Theoretical analysis indicate that this was attributed to two different growing mechanism determined by zinc super saturation ratio originated from the variation of the temperature in growth region.