Study on the impedance of aligned carbon microcoils embedded in silicone rubber matrix

This paper reports that carbon microcoils are grown through a chemical vapour deposit process, they are then embedded in silicone rubber, and manipulated to parallel with each other along their axes in the resulting composite. The impedance |Z| as well as phase angle θ of both the original carbon microcoil sheets and the aligned carbon microcoil/silicone rubber composites are measured. The results illustrate that carbon microcoils in different forms show different alternating current electric properties. The aligned carbon microcoils in the composites show stable parameters for f<10⁴ Hz but a sharp decrease in both |Z| and θ for frequencies >10⁴ Hz, which will also change as the carbon microcoils are extended. But, the original sheets have a pure resistance with their parameters stable throughout the entire alternating current frequency range investigated.     

复合碱媒介法合成棒状CdTe晶体

以Te粉和Cd(NO₃)₂为原料, 以联胺为还原剂, 采用复合氢氧化物媒介法, 在不同的反应条件下分别合成了棒状和立方体状的CdTe晶体, 其中棒状CdTe晶体的横向尺度为2～3 μm, 纵向尺度达几十微米. 选择反应温度为180 ℃并在反应体系中适量加水, 将有助于棒状CdTe的形成, 并提出了CdTe晶体的生长模型. X射线衍射图谱(XRD)以及紫外-可见分光吸收谱测试表明, 合成的棒状CdTe结晶性好, 吸收峰值位于近红外, 能带带隙值约为1.49 eV.