The effects of carbon nano tubes on electric and dielectric properties of CNTs doped KBr (CNTs/KBr) compound

Carbon nano tubes (CNTs) are synthesized by chemical vapor deposition method. We used X-ray diffraction and scanning electron microscopy, for characterization of the samples. After mixing different weight percentages (0–5 wt%) of the CNTs with potassium bromide insulator powder, we pressed it into pellets forming the CNTs/KBr compound samples. We investigated the DC electrical conductivity and dielectric properties of the compounds and applied the percolation theory to demonstrate the electrical property transition from insulator to conductor. We found that the DC conductivity of the samples increases with increasing CNTs in the compound and the electric percolation threshold is around 0.7 wt% CNTs and the critical exponent is 1.7.We investigated the capacity and dielectric function of the samples in different frequencies (10 Hz to 200 kHz) at room temperature, and studied the behavior of the real and imaginary parts of the dielectric function versus applied frequencies and CNTs percentages in the compound. We found that sample with 1.5 wt% CNT has higher dielectric constant.